Reversible phosphorylation of tonoplast proteins involves tonoplast-bound calcium-calmodulin-dependent protein kinase(s) and protein phosphatase(s)

1985 ◽  
Vol 4 (4) ◽  
pp. 199-201 ◽  
Author(s):  
Chantal Teulieres ◽  
Gilbert Alibert ◽  
Raoul Ranjeva
Keyword(s):  
Protein Kinase ◽  
Protein Phosphatase ◽  
Reversible Phosphorylation ◽  
Dependent Protein Kinase ◽  
Calcium Calmodulin Dependent ◽  
Dependent Protein

Characterization of a calcium/calmodulin-dependent protein phosphatase in the Limulus nervous tissue and its light regulation in the lateral eye

1994 ◽  
Vol 11 (5) ◽  
pp. 851-860 ◽  
Author(s):  
D. Z. Ellis ◽  
S. C. Edwards
Keyword(s):  
Protein Kinase ◽  
Protein Phosphatase ◽  
Regulatory Subunit ◽  
Free Calcium ◽  
Dependent Protein Kinase ◽  
Calmodulin Antagonist ◽  
Calcium Calmodulin Dependent ◽  
Lateral Eye ◽  
Dependent Protein

AbstractCalcium (Ca2+) plays an integral role in the light response of the photoreceptors in both vertebrate and invertebrate organisms. In the ventral eye of the horseshoe crab, Limulus polyphemus, a flash of light delivered to a dark-adapted photoreceptor stimulates a rapid rise in intracellular free calcium concentration ([Ca2+]i), which in turn mediates light adaptation. It has previously been demonstrated that in Limulus photoreceptors light, via Ca2+, activate s a calcium/calmodulin (Ca2+/CaM)-dependent protein kinase which increases the phosphorylation of arrestin. We now have identifie d biochemically, a calcium/calmodulin-dependent protein phosphatase (Ca2+/CaM PP ) in homogenates of the Limulus lateral and ventral eye, brain, and lateral optic nerve using as a substrate, a 32P-labeled peptide fragment of the regulatory subunit of cAMP-dependent protein kinase (RII). This protein phosphatase shares biochemical properties with calcineurin, a Ca2+/CaM-dependent protein phosphatase (type-2B). Its activity is enhanced by Ca2+, calmodulin and Mn2+; and is inhibited by mastoparan, a calmodulin antagonist, and a synthetic peptide corresponding to the autoinhibitory domain of mammalian calcineurin. Most importantly, light regulates the Ca2+/CaM PP activity in the lateral eye. While there is no difference in basal activity in long-term dark- or light-adapted preparations, Ca2+ enhances Ca2+/CaM PP activity only in long-term light-adapted eyes.

Abstract 190: Protein Phosphatase 2Ce Is a Novel Phospholamban Phosphatase that Exacerbates Cell Death and Suppresses Cardiac Contractility

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Toru Akaike ◽  
Gang Lu ◽  
Yibin Wang ◽  
Hongmei Ruan
Keyword(s):  
Cell Death ◽  
Protein Kinase ◽  
Protein Phosphatase ◽  
Ventricular Myocytes ◽  
Cardiac Contractility ◽  
Wild Type ◽  
Dependent Protein Kinase ◽  
Calcium Calmodulin Dependent ◽  
Dependent Protein ◽  
Phospholamban Phosphorylation

Regulation of sarcoplasmic reticulum (SR) calcium-ATPase (SERCA) activity is critical for calcium homeostasis in cardiomyocytes, and has a major impact on contractility and cellular viability of cardiomyocytes. The key regulators for SERCA activity include protein kinases, cAMP dependent protein kinase A and calcium/calmodulin dependent protein kinase II, and protein phosphatase 1. In this report, we have discovered that protein phosphatase 2Ce (PP2Ce) is a novel serine/threonine protein phosphatase specifically targeted to SR membrane in cardiomyocytes. PP2Ce was detected to interact with phosphlamban in heart. Recombinant PP2Ce protein showed a potent and specific activity towards the calcium/calmodulin dependent protein kinase II dependent phospholamban phosphorylation at threonin 17 site with no significant activity to cAMP dependent protein kinase A dependent phospholamban phosphorylation at serine 16 site. Expression of PP2Ce blunted β-adrenergic stimulated increase of phospholamban phosphorylation without affecting phosphorylation of ryanodine recepter or troponin I. PP2Ce expression reduced β-adrenergic stimulated intracellular calcium transient in isolated adult rabbit ventricular myocytes, and promoted hydrogen peroxide induced cell death in cultured neonatal rat ventricular myocytes. Transgenic mice with cardiac specific expression of PP2Ce showed no significant basal phenotype. However, in isolated perfusion heart preparation, β-adrenergic stimulated contractility was significant reduced in PP2Ce transgenic hearts comparing to wild type controls. Furthermore, we observed significantly larger infarct sizes and more impaired functional recovery following global ischemia/reperfusion injury in the transgenic hearts comparing to wild type controls. Therefore, PP2Ce is a novel component of SR calcium regulatory network that has a potentially important role in cell death regulation and cardiac contractility.

scholarly journals Interaction between Salt-inducible Kinase 2 and Protein Phosphatase 2A Regulates the Activity of Calcium/Calmodulin-dependent Protein Kinase I and Protein Phosphatase Methylesterase-1

2014 ◽  
Vol 289 (30) ◽  
pp. 21108-21119 ◽  
Author(s):  
Chia-Wei Lee ◽  
Fu-Chia Yang ◽  
Hsin-Yun Chang ◽  
Hanyi Chou ◽  
Bertrand Chin-Ming Tan ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Phosphatase ◽  
Protein Phosphatase 2A ◽  
Dependent Protein Kinase ◽  
Calcium Calmodulin Dependent ◽  
Phosphatase 2A ◽  
Dependent Protein

scholarly journals Targeted Protein Kinase A and PP-2B Regulate Insulin Secretion through Reversible Phosphorylation*

Endocrinology ◽  
2001 ◽  
Vol 142 (3) ◽  
pp. 1218-1227 ◽  
Author(s):  
Linda B. Lester ◽  
Maree C. Faux ◽  
J. Brian Nauert ◽  
John D. Scott
Keyword(s):  
Insulin Secretion ◽  
Protein Kinase ◽  
Rinm5f Cells ◽  
Reversible Phosphorylation ◽  
Dependent Protein Kinase ◽  
Calcium Calmodulin Dependent ◽  
Insulin Secretagogues ◽  
Anchoring Protein ◽  
Dependent Protein ◽  
Synapsin 1

Abstract Protein kinases and phosphatases play key roles in integrating signals from various insulin secretagogues. In this study, we show that the activities of the cAMP-dependent protein kinase (PKA) and the calcium/calmodulin-dependent phosphatase, PP-2B are coordinated resulting in the regulation of insulin secretion. Transient inhibition of PP-2B, using the immunosuppressant FK506, increased forskolin stimulated insulin secretion by 2.5-fold ± 0.3 (n = 6) in rat islets and RINm5F cells. Surprisingly, forskolin treatment resulted in the dephosphorylation of the vesicle-associated protein synapsin 1 and increased PP-2B activity by 2.98 ± 0.97-fold (n = 4). One potential explanation for the observed coordination of PKA and PP-2B activity is their colocalization through a mutual anchoring protein, AKAP79/150. Accordingly, RINm5F cells expressing AKAP79 exhibited decreased insulin secretion, reduced PP-2B activity and were insensitive to FK506. This suggests that AKAP targeting of PKA and PP-2B maintains a signal transduction complex that may regulate reversible phosphorylation events involved in insulin secretion.

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