Log in

Relevant bibliographies by topics / Ca(2+)-calmodulin dependent protein kinase

Contents

Journal articles
Dissertations / Theses
Books
Book chapters
Conference papers

Academic literature on the topic 'Ca(2+)-calmodulin dependent protein kinase'

Author: Grafiati

Published: 4 June 2021

Last updated: 3 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Ca(2+)-calmodulin dependent protein kinase.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Ca(2+)-calmodulin dependent protein kinase"

1

Lee, J. C., and A. M. Edelman. "A protein activator of Ca(2+)-calmodulin-dependent protein kinase Ia." Journal of Biological Chemistry 269, no. 3 (January 1994): 2158–64. http://dx.doi.org/10.1016/s0021-9258(17)42149-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Mayer, P., M. Möhlig, U. Seidler, H. Rochlitz, M. Fährmann, H. Schatz, H. Hidaka, and A. Pfeiffer. "Characterization of γ- and δ-subunits of Ca2+/calmodulin-dependent protein kinase II in rat gastric mucosal cell populations." Biochemical Journal 297, no. 1 (January 1, 1994): 157–62. http://dx.doi.org/10.1042/bj2970157.

Full text

Abstract:

We searched for the occurrence of a Ca2+/calmodulin-dependent protein kinase in rat gastric cell types as a likely member in the chain of gastrin- and muscarinic-receptor-mediated signal transmission. A Ca(2+)- and calmodulin-dependent phosphorylation of major 50, 60 and 100 kDa substrates was observed in parietal cell cytosol and a major 60 and 61 kDa protein doublet was found to bind 125I-calmodulin in 125I-calmodulin-gel overlays. A specific substrate of the multifunctional Ca2+/calmodulin-dependent protein kinase II, autocamtide II, was phosphorylated in a calmodulin-dependent manner. The specific inhibitor of this enzyme, KN-62, antagonized protein kinase activity. RNA extracted from gastric mucosal cells was shown to contain sequences of the gamma- and delta- but not alpha- and beta-subunits of the calmodulin-dependent kinase II, and mRNA of both subtypes was demonstrated in highly purified parietal, chief and mucous cells. A calmodulin-dependent kinase II composed of gamma- and delta-subunits is a likely mediator of Ca(2+)-dependent signal transmission in these populations of gastric cells.

APA, Harvard, Vancouver, ISO, and other styles

3

Chenglong, Liu, Liu Haihua, Zhang Fei, Zheng Jie, and Wei Fang. "Scutellarin Mitigates Cancer-Induced Bone Pain by Suppressing CaMKII/CREB Pathway in Rat Models." Current Topics in Nutraceutical Research 17, no. 3 (April 1, 2019): 249–53. http://dx.doi.org/10.37290/ctnr2641-452x.17:249-253.

Full text

Abstract:

Cancer-induced bone pain is a severe and complex pain caused by metastases to bone in cancer patients. The aim of this study was to investigate the analgesic effect of scutellarin on cancer-induced bone pain in rat models by intrathecal injection of Walker 256 carcinoma cells. Mechanical allodynia was determined by paw withdrawal threshold in response to mechanical stimulus, and thermal hyperalgesia was indicated by paw withdrawal latency in response to noxious thermal stimulus. The paw withdrawal threshold and paw withdrawal latencies were significantly decreased after inoculation of tumor cells, whereas administration of scutellarin significantly attenuated tumor cell inoculation-induced mechanical and heat hyperalgesia. Tumor cell inoculation-induced tumor growth was also significantly abrogated by scutellarin. Ca²⁺/calmodulin-dependent protein kinase II is a multifunctional kinase with up-regulated activity in bone pain models. The activation of Ca²⁺/calmodulin-dependent protein kinase II triggers phosphorylation of cAMP-response element binding protein. Scutellarin significantly reduced the expression of phosphorylated-Ca²⁺/calmodulin-dependent protein kinase II and phosphorylated-cAMP-response element binding protein in cancer-induced bone pain rats. Collectively, our study demonstrated that scutellarin attenuated tumor cell inoculation-induced bone pain by down-regulating the expression of phosphorylated-Ca²⁺/calmodulin-dependent protein kinase II and phosphorylated-cAMP-response element binding protein. The suppressive effect of scutellarin on phosphorylated-Ca²⁺/calmodulin-dependent protein kinase II/phosphorylated-cAMP-response element binding protein activation may serve as a novel therapeutic strategy for CIBP management.

APA, Harvard, Vancouver, ISO, and other styles

4

Purohit, Anil, Adam G. Rokita, Xiaoqun Guan, Biyi Chen, Olha M. Koval, Niels Voigt, Stefan Neef, et al. "Oxidized Ca 2+ /Calmodulin-Dependent Protein Kinase II Triggers Atrial Fibrillation." Circulation 128, no. 16 (October 15, 2013): 1748–57. http://dx.doi.org/10.1161/circulationaha.113.003313.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Yuan, W., and D. M. Bers. "Ca-dependent facilitation of cardiac Ca current is due to Ca-calmodulin-dependent protein kinase." American Journal of Physiology-Heart and Circulatory Physiology 267, no. 3 (September 1, 1994): H982—H993. http://dx.doi.org/10.1152/ajpheart.1994.267.3.h982.

Full text

Abstract:

Repetitive membrane potential (Em) depolarization from -90 to 0 mV in rabbit and ferret ventricular myocytes induces a facilitation or "staircase" of Ca current (ICa), which is Ca (not Em) dependent and takes several seconds to accumulate and dissipate. That is, ICa at the tenth pulse at 1-2 Hz exceeds that at the first pulse (I10 > I1). The ICa staircase was completely abolished by dialysis with either of two inhibitory peptides of Ca-calmodulin-dependent protein kinase (CaMKII) CaMKII(290-309) and CaMKII(273-302)], implicating this kinase. Inclusion of ATP gamma S in the patch pipette gradually increased ICa but also abolished the staircase implicating phosphorylation. KN-62, a nonpeptide CaMKII inhibitor, reversed the ICa staircase (I1 > I10). However, this effect of KN-62 was largely attributed to a slower recovery from inactivation and a gating shift to more negative Em (not seen with CaMKII peptides). Similar results were obtained with H-89 and staurosporine (inhibitors of adenosine 3',5'-cyclic monophosphate and phospholipid-/Ca-dependent protein kinase, respectively). The reversal of the ICa staircase with H-89 and KN-62 could be prevented by more negative interpulse Em or elevation of extracellular [Ca] (which could counteract changes in channel gating due to a reduction in internal negative surface potential). That is, these kinase inhibitors might decrease phosphorylation at the inner membrane surface. In approximately 30% of the cells studied with H-89 and staurosporine the characteristic kinetic difference in ICa inactivation (faster at I1 than I10) was also diminished. This might be due to a relatively nonspecific inhibition of the same protein kinase inhibited by the CaMKII peptides. We conclude that the Ca-dependent ICa facilitation is due to activation of CaMKII and phosphorylation of a site on or near the Ca channel. KN-62, H-89, and staurosporine shifted ICa gating to more negative potentials and slowed recovery from inactivation, effects that could be due to reduction in phosphorylation at the inner membrane surface. Thus the reversal of the ICa staircase by KN-62, H-89, and staurosporine may not be Ca channel specific.

APA, Harvard, Vancouver, ISO, and other styles

6

Menegon, A., D. D. Dunlap, F. Castano, F. Benfenati, A. J. Czernik, P. Greengard, and F. Valtorta. "Use of phosphosynapsin I-specific antibodies for image analysis of signal transduction in single nerve terminals." Journal of Cell Science 113, no. 20 (October 15, 2000): 3573–82. http://dx.doi.org/10.1242/jcs.113.20.3573.

Full text

Abstract:

We have developed a semi-quantitative method for indirectly revealing variations in the concentration of second messengers (Ca(2+), cyclic AMP) in single presynaptic boutons by detecting the phosphorylation of the synapsins, excellent nerve terminal substrates for cyclic AMP- and Ca(2+)/calmodulin-dependent protein kinases. For this purpose, we employed polyclonal, antipeptide antibodies recognising exclusively synapsin I phosphorylated by Ca(2+)/calmodulin-dependent protein kinase II (at site 3) or synapsins I/II phosphorylated by either cAMP-dependent protein kinase or Ca(2+)/calmodulin-dependent protein kinase I (at site 1). Cerebellar granular neurones in culture were double-labelled with a monoclonal antibody to synapsins I/II and either of the polyclonal antibodies. Digitised images were analysed to determine the relative phosphorylation stoichiometry at each individual nerve terminal. We have found that: (i) under basal conditions, phosphorylation of site 3 was undetectable, whereas site 1 exhibited some degree of constitutive phosphorylation; (ii) depolarisation in the presence of extracellular Ca(2+) was followed by a selective and widespread increase in site 3 phosphorylation, although the relative phosphorylation stoichiometry varied among individual terminals; and (iii) phosphorylation of site 1 was increased by stimulation of cyclic AMP-dependent protein kinase but not by depolarisation and often occurred in specific nerve terminal sub-populations aligned along axon branches. In addition to shedding light on the regulation of synapsin phosphorylation in living nerve terminals, this approach permits the spatially-resolved analysis of the activation of signal transduction pathways in the presynaptic compartment, which is usually too small to be studied with other currently available techniques.

APA, Harvard, Vancouver, ISO, and other styles

7

Lu, H. K., R. J. Fern, J. J. Nee, and P. Q. Barrett. "Ca(2+)-dependent activation of T-type Ca2+ channels by calmodulin-dependent protein kinase II." American Journal of Physiology-Renal Physiology 267, no. 1 (July 1, 1994): F183—F189. http://dx.doi.org/10.1152/ajprenal.1994.267.1.f183.

Full text

Abstract:

The T-type Ca2+ channel is unique among voltage-dependent Ca2+ channels in its low threshold for opening and its slow kinetics of deactivation. Here, we evaluate the importance of intracellular Ca2+ (Cai2+) in promoting low-threshold gating of T-type channels in adrenal glomerulosa cells. We observe that 390 nM to 1.27 microM Cai2+ enhances T-type current by shifting the voltage dependence of channel activation to more negative potentials. This Ca(2+)-induced shift is mediated by calmodulin-dependent protein kinase II (CaMKII), because it is abolished by inhibitors of CaMKII but not of protein kinase C and is subsequently restored by exogenous calmodulin. This Ca(2+)-induced reduction in gating threshold would render T-type Ca2+ channels uniquely suited to transduce depolarizing stimuli of low amplitude into a Ca2+ signal sufficient to support a physiological response.

APA, Harvard, Vancouver, ISO, and other styles

8

Lecocq, R., F. Lamy, C. Erneux, and J. E. Dumont. "Rapid purification and identification of calcyphosine, a Ca2+-binding protein phosphorylated by protein kinase A." Biochemical Journal 306, no. 1 (February 15, 1995): 147–51. http://dx.doi.org/10.1042/bj3060147.

Full text

Abstract:

A method is presented for the rapid purification of dog thyroid calcyphosine, a protein previously identified as a major substrate for cyclic AMP-dependent protein kinase in dog thyroid slices stimulated by thyrotropin [Lecocq, Lamy and Dumont (1979) Eur. J. Biochem. 102, 147-152]. The protein was previously identified as a spot on two-dimensional gels and is now purified in its native form by a procedure involving three chromatographic steps. Homogeneous calcyphosine identified by SDS/PAGE, immunoblotting and peptide sequencing can be obtained within 7 h. As for calmodulin, Ca(2+)-dependent conformational changes can be shown by Ca(2+)-dependent hydrophobic interaction chromatography using phenyl-Sepharose. Unlike calmodulin, calcyphosine is a substrate for protein kinase A.

APA, Harvard, Vancouver, ISO, and other styles

9

Rokolya, A., M. P. Walsh, and R. S. Moreland. "Calcium-and phorbol ester-dependent calponin phosphorylation in homogenates of swine carotid artery." American Journal of Physiology-Heart and Circulatory Physiology 271, no. 2 (August 1, 1996): H776—H783. http://dx.doi.org/10.1152/ajpheart.1996.271.2.h776.

Full text

Abstract:

Calponin inhibits actin-activated myosin adenosinetriphosphatase (ATPase) activity, and phosphorylation reverses this inhibition. Calponin phosphorylation has been demonstrated in reconstituted contractile protein systems, but studies using intact smooth muscle have produced mixed results. The goal of this study was to determine if vascular smooth muscle contains the necessary biochemical machinery to catalyze calponin phosphorylation. We used swine carotid homogenate, which allows access to the intracellular components and contains all endogenous proteins and enzymes in physiologically relevant concentrations. We demonstrated that calponin is phosphorylated in response to Ca2+ (0.27 +/- 0.04 mol P(i)/mol calponin) and in response to phorbol 12,13-dibutyrate in the presence or absence of Ca2+ (0.48 +/- 0.09 mol P(i)/mol calponin). Calponin phosphorylation was inhibited by the protein kinase C inhibitor staurosporine but not by the Ca(2+)- and calmodulin-dependent protein kinase II inhibitor KN-62. We conclude that Ca(2+)-dependent and -independent isoforms of protein kinase C but not the Ca(2+) -and calmodulin-dependent protein kinase II catalyze calponin phosphorylation in the swine carotid artery.

APA, Harvard, Vancouver, ISO, and other styles

10

Bosser, R., M. Faura, J. Serratosa, J. Renau-Piqueras, M. Pruschy, and O. Bachs. "Phosphorylation of rat liver heterogeneous nuclear ribonucleoproteins A2 and C can be modulated by calmodulin." Molecular and Cellular Biology 15, no. 2 (February 1995): 661–70. http://dx.doi.org/10.1128/mcb.15.2.661.

Full text

Abstract:

It was previously reported that the phosphorylation of three proteins of 36, 40 to 42, and 50 kDa by casein kinase 2 is inhibited by calmodulin in nuclear extracts from rat liver cells (R. Bosser, R. Aligué, D. Guerini, N. Agell, E. Carafoli, and O. Bachs, J. Biol. Chem. 268:15477-15483, 1993). By immunoblotting, peptide mapping, and endogenous phosphorylation experiments, the 36- and 40- to 42-kDa proteins have been identified as the A2 and C proteins, respectively, of the heterogeneous nuclear ribonucleoprotein particles. To better understand the mechanism by which calmodulin inhibits the phosphorylation of these proteins, they were purified by using single-stranded DNA chromatography, and the effect of calmodulin on their phosphorylation by casein kinase 2 was analyzed. Results revealed that whereas calmodulin inhibited the phosphorylation of purified A2 and C proteins in a Ca(2+)-dependent manner, it did not affect the casein kinase 2 phosphorylation of a different protein substrate, i.e., beta-casein. These results indicate that the effect of calmodulin was not on casein kinase 2 activity but on specific protein substrates. The finding that the A2 and C proteins can bind to a calmodulin-Sepharose column in a Ca(2+)-dependent manner suggests that this association could prevent the phosphorylation of the proteins by casein kinase 2. Immunoelectron microscopy studies have revealed that such interactions could also occur in vivo, since calmodulin and A2 and C proteins colocalize on the ribonucleoprotein particles in rat liver cell nuclei.

APA, Harvard, Vancouver, ISO, and other styles

More sources

Dissertations / Theses on the topic "Ca(2+)-calmodulin dependent protein kinase"

1

Choo, Hyeran. "Ca²⁺/calmodulin-dependent protein kinase II regulates the growth of human osteosarcoma cells in vivo." Thesis, Birmingham, Ala. : University of Alabama at Birmingham, 2007. http://www.mhsl.uab.edu/dt/2007m/choo.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Yost, Cynthia Haycox. "Regulation of the dorsal-ventral axis in Xenopus embryos by intracellular components of the Wnt pathway /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/9224.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Takao, Keizo. "Visualization of synaptic Ca[2+]/calmodulin dependent protein kinase 2 activity in living neurons." 京都大学 (Kyoto University), 2006. http://hdl.handle.net/2433/144322.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Ljungdahl, Sofia. "Role of MAP kinase pathways in maintenance of the transformed phenotype /." Stockholm, 1998. http://diss.kib.ki.se/1998/91-628-2829-0.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Pierce, Sarah B. "The role of glycogen synthase kinase 3 in early xenopus development /." Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/9204.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

BEAUMAN, SHIRELYN RAE. "THE FUNCTION OF CALCIUM/CALMODULIN DEPENDENT PROTEIN KINASE II IN CELL CYCLE REGULATION." University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1054300335.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Traub, Oren. "Mechanisms of shear stress-mediated ERK1/2 modulating signal transduction pathways in endothelial cells /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/6309.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Kimura(Takemoto), Sayaka. "Molecular cloning and characterization of CLICK-3/CaMKIγ, a novel membrane-anchored neuronal Ca[2+]/calmodulin-dependent protein kinase (CaMK)." Kyoto University, 2003. http://hdl.handle.net/2433/148486.

Full text

Abstract:

Kyoto University (京都大学)
0048
新制・課程博士
博士(医学)
甲第10449号
医博第2648号
新制||医||844(附属図書館)
UT51-2003-T275
京都大学大学院医学研究科脳統御医科学系専攻
(主査)教授月田承一郎, 教授中西重忠, 教授武藤誠, 教授成宮周
学位規則第4条第1項該当

APA, Harvard, Vancouver, ISO, and other styles

9

Dong, Yu. "Ca²⁺/calmodulin dependent protein kinase II subcellular re-distribution and activation of protein phosphatase after a brief pentylenetetrazol seizure potential role in kindling /." Connect to full-text via OhioLink ETD Center, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=mco1082463968.

Full text

Abstract:

Thesis (Ph. D.)--Medical College of Ohio, 2003.
"In partial fulfillment of the requirements for the degree of Doctor of Philosophy in Medical Sciences." Major advisor: Howard Rosenberg. Document formatted into pages: iv, 144 p. Title from title page of PDF document. Includes bibliographical references (p. 104-132).

APA, Harvard, Vancouver, ISO, and other styles

10

Aydin, Jan. "Skeletal muscle calcium homeostasis during fatigue : modulation by kinases and mitochondria /." Stockholm : Karolinska institutet, 2007. http://diss.kib.ki.se/2007/978-91-7357-247-7/.

Full text

APA, Harvard, Vancouver, ISO, and other styles

More sources

Books on the topic "Ca(2+)-calmodulin dependent protein kinase"

1

Means, Anthony R. Calcium regulation of cellular function. New York: Raven Press, 1995.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Ca(2+)-calmodulin dependent protein kinase"

1

Ohba, Takashi, Yasutaka Ohta, Kohji Miyazaki, Hitoshi Okamura, and Eishichi Miyamoto. "Fetal Calf Serum: Eliciting Phosphorylation of Ca++/Calmodulin-Dependent Protein Kinase II in Cultured Rat Granulosa Cells." In Signaling Mechanisms and Gene Expression in the Ovary, 218–24. New York, NY: Springer New York, 1991. http://dx.doi.org/10.1007/978-1-4612-3200-1_20.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Mahoney, C. W., and A. Azzi. "The Structure and Function of Ca+2 - and Phospholipid- Dependent Protein Kinase (Protein Kinase C), A Trans-Membrane Signal Transducer." In Dynamics of Membrane Proteins and Cellular Energetics, 2–18. Berlin, Heidelberg: Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/978-3-642-73905-7_1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Popoli, M., S. Mori, S. Garbini, C. Vocaturo, J. Perez, and G. Racagni. "cAMP-and Ca₂₊/Calmodulin-Dependent Protein Phosphorylation in the Action of Antidepressant Drugs: Early Action of Venlafaxine." In New Therapeutic Indications of Antidepressants, 26–31. Basel: KARGER, 1997. http://dx.doi.org/10.1159/000061357.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Hudmon, Andy, and Howard Schulman. "Calcium/Calmodulin-Dependent Protein Kinase II." In Reference Module in Life Sciences. Elsevier, 2020. http://dx.doi.org/10.1016/b978-0-12-819460-7.00099-2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Hudmon, Andy, and Howard Schulman. "Calcium/Calmodulin-Dependent Protein Kinase II." In Encyclopedia of Biological Chemistry, 274–80. Elsevier, 2004. http://dx.doi.org/10.1016/b0-12-443710-9/00654-2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Picciotto, Marina R., Kent L. Nastiuk, and Angus C. Nairn. "Structure, Regulation, and Function of Calcium/Calmodulin-Dependent Protein Kinase I." In Advances in Pharmacology, 251–75. Elsevier, 1996. http://dx.doi.org/10.1016/s1054-3589(08)60585-2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

"CA+2-CALMODULIN-ACTIVATED PROTEIN KINASE IN STRUCTURALLY INTACT KIDNEY MITOCHONDRIA PHOSPHORYLATES THE ENDOGENOUS FERREDOXIN: MODULATION OF la- AND 24-HYDROXYLASES OF 25-HYDROXYVTTAMIN D3." In Vitamin D, 261–62. De Gruyter, 1991. http://dx.doi.org/10.1515/9783110850345-073.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Ca(2+)-calmodulin dependent protein kinase"

1

Gocher, Angela M., Gissou Azabdaftari, and Arthur M. Edelman. "Abstract A12: Regulation of ovarian cancer OVCAR-3 cell proliferation and viability by calcium/calmodulin-dependent protein kinase kinase 2." In Abstracts: AACR Special Conference on Advances in Ovarian Cancer Research: From Concept to Clinic; September 18-21, 2013; Miami, FL. American Association for Cancer Research, 2013. http://dx.doi.org/10.1158/1078-0432.ovca13-a12.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Gocher, Angela M., Thomas F. Franke, Gissou Azabdaftari, Loukia G. Karacosta, and Arthur M. Edelman. "Abstract B13: Regulation of Akt activity, cell proliferation, and viability in ovarian cancer cells by calcium/calmodulin-dependent protein kinase kinase 2." In Abstracts: AACR Special Conference: Targeting the PI3K-mTOR Network in Cancer; September 14-17, 2014; Philadelphia, PA. American Association for Cancer Research, 2015. http://dx.doi.org/10.1158/1538-8514.pi3k14-b13.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Ware, J. A., M. Smith, and E. W. Salzman. "DIACYLGLYCEROL AND PHORBOL ESTER REDUCE AEQUORIN-INDICATED [Ca++] ELEVATIONS INDUCED BY THROMBIN OR ADP." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644503.

Full text

Abstract:

Platelet aggregation and secretion induced by phorbol ester (PMA) or diacylglycerol (DAG) are preceded by an increase in [Ca++] that is detected byaequorin, but not by quin2, fura-2, or indo-1, suggesting that these indicatorsreflect different aspects of Ca++ homeostasis, possibly different functional Ca++ pools. Addition of two conventional agonists in subthreold concentrations synergistically enhances the [Ca++] rise and aggregation.However, if PMA or DAG is the first agonist the subsequent quin2-indicated [Ca++] rise after thrombin is reduced.Whether aequorin-indicated [Ca++] is similarly affected is unknown. We studied gel-filtered platelets loaded with aequorin or a fluorophore and added PMA, DAG, thrombin or ADP, alone or in combination. Either PMA or DAG alone caused a concentration-dependent increase in [Ca++] detectable with aequorin but not with the fluorophores; simultaneous addition of thrombin or ADP with DAG or PMA produced a larger [Ca++] rise than either alone. However, addition of DAG or PMA as a first agonist reduced subsequent aequorin-indicated [Ca++] rises following thrombin or ADP in a concentration and time-dependent manner. Inhibition of ADP or thrombin-induced [Ca++] rise was not always accompanied by inhibition of aggregation or secretion. Combination of subthreshold concentrations of ADP and thrombin produced an enhanced [Ca++] rise and aggregation. However, this synergistic effect was inhibited by preincubation with DAG or PMA. Neither this effect nor DAG-induced [Ca++] rise was inhibited by the protein kinase C inhibitor H-7. In genera^ preincubation of platelets with an agonist enhances Ca rise and aggregation in response to a second agonist; in contrasl protein kinase C activators, which themselves elevate [Ca++] as shown by aequorin, inhibit aequorin-indicated Ca rises after ADP or thrombin, and limit synergism between these two agonists.

APA, Harvard, Vancouver, ISO, and other styles

4

Enouf, J., R. Bredoux, A. Giraud, N. Bourdeau, and S. Levy-Toledano. "POSSIBLE RELATIONSHIP BETWEEN THE 23-kDa PHOSPHOPROTEIN AND THE IP3 -INDUCED Ca2+RELEASE IN HUMAN PLATELETS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644516.

Full text

Abstract:

The regulation of Ca2+ concentration in human platelets involves intracellular membranes i.e. dense tubular system (DTS). Agonist-induced platelet activation generates inositol 1,4,5 trisphosphate (IP3) which is responsible for Ca2+ mobilization from DTS. However, its mechanism of action is still unknown. cAMP has been shown to regulate Ca2+ transport by isolated membrane vesicles. This effect was correlated with the phosphorylation of a 23 kDa protein. We investigated whether this phosphorylation could play a role in the mechanism of IP3-induced Ca release.We isolated a membrane fraction enriched in intracellular membranes, which actively sequesters Ca2++. The Ca2+ uptake was mediated by a characterized (Ca2+ + Mg2+)-ATPase of a molecular weight 120 kDa. As well, the characterization of the 23-kDa protein phosphorylation by the catalytic subunit of the cAMP dependent protein kinase (C. Sub.) has been achieved. IP^-induced Ca release was tested on our membrane preparations. The transient effect was maximal at one minute and a dose-response curve was obtained.The cAMP dependent phosphorylation of the 23-kDa protein increased the Ca2+ liberation induced by IP by two fold whatever the IP3 concentration. The addition on the protein kinase inhibitor inhibited the IP3 -induced Ca2+ release.The effect of IP3 on the cAMP-mediated phosphorylation of the 23-kDa protein has been examinated.A dose dependent stimu-ulation of the 23-kDa protein phosphorylation in the presence of C. Sub. was initiated by IP3. The maximal effect was observed after 1-2 min and obtained with an IP3 concentration similar to that producing the maximal calcium release. The stimulation of the phosphorylation by IP3 was detected in the absence of Ca2+ and in the presence of phosphatase inhibitors.Therefore, we suggest a possible correlation between cAMP dependent phosphorylation of the 23-kDa protein and the IP3-induced Ca2+ release in human platelet membrane vesicles.

APA, Harvard, Vancouver, ISO, and other styles

5

SIMON, M. F., H. CHAP, and L. DOUSTE-BLAZY. "EFFECTS OF SIN 1 ON PLATELET ACTIVATION INDUCED BY THROMBIN IN HUMAN PLATELETS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643423.

Full text

Abstract:

The mechanism of platelet activation is well known. The interaction of agonist such as thrombin, on specific membrane receptor induces phosphatidylinositol-specific phospholipase C activation, with a concomitant formation of two second messengers (from PIP2): inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG). IP3 is able to induce a rapid discharge of Ca2+ from internal stores and Ca2+ influx through plasma membrane by unidentified Ca2+ channels linked to receptor activation. The increase of cytoplasmic free calcium concentration leads to the activation of the calcium calmodulin dependent myosine light chain kinase which phosphoryla-tes 20 kD proteins (myosine light chain). DAG is a potent activator of protein kinase C, which phosphorylates 40 kD proteins. These different pathways act in synergism.Sin 1 is a platelet aggregating inhibitor. This compound is an active metabolite of molsidomine, which activates platelet guany-late cyclase, inducing a rapid rise in cyclic GMP level. The precise role of cyclic GMP in platelet activation is not yet known. In order to study the mechanism of action of this drug, we tried to determine the effect of Sin 1 on the different steps described above. We measured Ca2+ fluxes and phospholipase C activation in thrombin (0,5 U/ml) stimulated platelets in the presence of different doses of Sin 1 (10™7-10™3M). Serotonin secretion was inhibited by 30 % with Sin 1 (10™4M-10™5m). A parallel inhibition of phospholipase C was detected by measurement of [32P)-PA level. Platelets loaded with Quin 2 and stimulated by thrombin showed a 70 % inhibition of external Ca2+ influx as soon as a concentration of 10™7M of Sin 1 was added. A study on platelet loaded with [45Ca2+) and Quin 2 confirmed these results. On the contrary, discharge of internal Ca2+ store seemed to be unaffected.In conclusion, the major effect of Sin 1 on platelet phospholipase C pathway is an inhibition of Ca2+ influx through plasma membrane. Some further experiments are necessary to shown whether this inhibition is correlated with cyclic GMP formation (the major effect of Sin 1) and try to establish a relation between this inhibition and that exerted on phospholipase C.Sin 1 was a generous gift of Hoechst.

APA, Harvard, Vancouver, ISO, and other styles

6

Ye, Jianfeng, Baoguo Chen, and Lisa X. Xu. "Shear Stress Effect on the Production of Nitric Oxide in Cultured Rat Aorta Endothelial Cells." In ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-33074.

Full text

Abstract:

Atherosclerotic lesions tend to develop in regions where there are separations from unidirectional laminar blood flow, typically near branches, bifurcations, regions of arterial narrowing, and curvatures in the arteries (1, 2). Obviously, homodynamic forces play a key role in atherosclerosis. Studies also indicate that vascular endothelium function disturbance, especially impairment of endothelium dependent vasodilation, is involved (3). Shear stress affects endothelial cells in many ways, such as cytoskeletal rearrangement, decrease of intracellular pH, release of PGI2 and some growth factors (PDGF, FGF, ECGF, TGF-b, etc), activation of IP3 and mitogen-activated protein kinases, and the significant increase in the production of nitric oxide (1,2,4,5). As an important function factor of vascular endothelial cells, nitric oxide (NO) is closely related to the endothelial dysfunction and atherosclerosis (6). Endothelial derived nitric oxide involves in many events in the vasculature, including vasodilation, inhibition of platelet aggregation, adhesion molecule expression, and vascular smooth muscle proliferation, which are directly or indirectly related to atherosclerosis. Endothelial cells release NO more potently in response to increased shear stress than to agonists that raise intracellular free calcium concentration [Ca2+]i. Studies have indicated that NO production increases with a calcium/CaM dependent manner in the first few minutes after exposed to shear stress, followed by a sustained NO production that occurs more than 30min which is Ca2+ independent (7). The activation of eNOS by shear stress, which modulated by Ca/CaM, G protein, tyrosine kinase phosphorylation and eNOS gene expression, is responsible for the increase of NO production (8). However, the contribution of extracellular calcium to the production of NO is somewhat contradictory.

APA, Harvard, Vancouver, ISO, and other styles

7

Sakon, M., Y. Uemura, K. Suga, T. Tsujinaka, J. Kambayashi, and T. Mori. "STUDIES ON PHOSPHATASES IN HUMAN PLATELETS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644494.

Full text

Abstract:

Activation of platelets by various agonists has been ascribed to be associated with phosphorylation and dephosphorylation of specific proteins such as 20K and 47K polypeptide. Although protein kinases such as myosin light chain kinase and C kinase have been extensively studied, little information is currently available on platelet phosphatases, which may play a crucial role in the regulation of stimulus-linked protein phosphorylation. Thereby, the present study was conducted to know some characters of platelet phosphatases. Glycerol loaded platelets prepared from human platelet concentrates were subjected to osmotic lysis in 20 mM HEPES-NaOH buffer containing 5 mM EDTA, 0.5 mM dithio-threitol and various protease inhibitors and a soluble fraction was obtained by centrifugation, The activity of phosphatase was assayed at pH 7.35, using paranitrophenylphosphate as a substrate. Leupeptin and EDTA were added to the reaction mixture to avoid proteolytic attack to the enzyme. The neutral phosphatase was partially purified from the soluble fraction by a combination of ammonium sulfate fractionation and column chromatographies. Five distinct peaks with neutral phosphatase activity were obtained by a linear gradient elution ( 0−0.5 M KCl ) in DEAE Sepharose CL-6B of 0−60 % ammonium sulfate precipitate. The phosphatase activity of one peak eluted at 0.2M KCl was maximum at pH below 6, which was considered to be acid phosphatase, and the remaining four peaks' optimal pH was between 7.0−7.5. These four peaks were termed as PH-I (passed through fraction), PH-II (0.1M KCl), PH-III (0.25M KCl) and PH-IV (0.3M KCl). The respective peak was eluted as a single peak on Ultrigel AcA 34 and the molecular weight was estmated as follows; I-55K, II-40K, III-55K, IV-37K. PH-I − II were active in the presnce of EDTA and were not affect ed by divalent cations (Mg++ , Mn++ , Ca++ ) , whereas PH-III was highly dependent upon Mg++. The activity of PH-IV was completely dependent on Mn++. From these observations, the following conclusions were obtained; (1) Human platelets contain four species of neutral phosphatases, in addition to acid phosphatase. (2) Each neutral phosphatase is distincive by molecular weight and requirement of divalent cations.

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!