Calcium/calmodulin-dependent protein kinase II is phosphorylated by protein kinase C in vitro

Biochemistry ◽  
1993 ◽  
Vol 32 (11) ◽  
pp. 2923-2930 ◽  
Author(s):  
M. Neal Waxham ◽  
Jaroslaw Aronowski
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Dependent Protein Kinase ◽  
Calcium Calmodulin Dependent ◽  
Kinase C ◽  
Protein Kinase Ii ◽  
Dependent Protein

scholarly journals Calponin phosphorylation in vitro and in intact muscle

1993 ◽  
Vol 296 (3) ◽  
pp. 827-836 ◽  
Author(s):  
S J Winder ◽  
B G Allen ◽  
E D Fraser ◽  
H M Kang ◽  
G J Kargacin ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Gel Electrophoresis ◽  
Dependent Protein Kinase ◽  
Kinase C ◽  
Sds Page ◽  
Protein Kinase Ii ◽  
Dependent Protein

Calponin, a thin-filament-associated protein implicated in the regulation of smooth-muscle contraction, is phosphorylated in vitro by protein kinase C and Ca2+/calmodulin-dependent protein kinase II [Winder and Walsh (1990) J. Biol. Chem. 265, 10148-10155] and dephosphorylated by a type 2A protein phosphatase [Winder, Pato and Walsh (1992) Biochem. J. 286, 197-203]. Unphosphorylated calponin binds to actin and inhibits the actin-activated myosin MgATPase; these properties are lost on phosphorylation. Although both serine and threonine residues in calponin are phosphorylated, the major site of phosphorylation by either kinase is Ser-175. Calponin also undergoes phosphorylation when bound to actin in synthetic thin filaments, in a reconstituted actomyosin system, in washed myofibrils and in tissue extracts; this results in dissociation of calponin from actin. Tryptic phosphopeptide mapping indicates that the same sites are phosphorylated in the bound as in the isolated protein. Toad stomach calponin exists in at least three isoforms which differ in charge but exhibit the same molecular mass on SDS/PAGE. In a toad stomach extract, all three isoforms are phosphorylated by protein kinase C or Ca2+/calmodulin-dependent protein kinase II as shown by two-dimensional gel electrophoresis (non-equilibrium pH-gradient gel electrophoresis and SDS/PAGE). Calponin phosphorylation also occurs in intact toad stomach smooth-muscle strips metabolically labelled with 32Pi and stimulated to contract with carbachol. These results support the hypothesis that calponin may be regulated in vivo by phosphorylation-dephosphorylation.

scholarly journals Neuronal Protection and Preservation of Calcium/Calmodulin-Dependent Protein Kinase II and Protein Kinase C Activity by Dextrorphan Treatment in Global Ischemia

1993 ◽  
Vol 13 (4) ◽  
pp. 550-557 ◽  
Author(s):  
Jaroslaw Aronowski ◽  
M. Neal Waxham ◽  
James C. Grotta
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Neuronal Morphology ◽  
Global Ischemia ◽  
Specific Substrate ◽  
Dependent Protein Kinase ◽  
Calcium Calmodulin Dependent ◽  
Kinase C ◽  
Protein Kinase Ii ◽  
Dependent Protein

This study analyzed the ability of the N-methyl-d-aspartate receptor antagonist dextrorphan (DX) to prevent neuronal degeneration (analyzed by light microscopy), calmodulin (CaM) redistribution (analyzed by immunocytochemistry) and changes in activity of two major Ca2+-dependent protein kinases—calcium/calmodulin-dependent protein kinase II (CaM-KII) and protein kinase C (PKC) (analyzed by specific substrate phosphorylation) after 20 min of global ischemia (four-vessel occlusion model) in rats. DX treatment before and after ischemia significantly protected hippocampal and cortical neurons from neurodegeneration whereas DX posttreatment alone did not have any effect on preservation of neuronal morphology as compared with placebo treatment analyzed 72 h after 20 min of ischemia. Similarly to histological changes, DX exhibited protection against redistribution of CaM observed after ischemia. These changes were detected both in hippocampus as well as in cerebral cortex. Finally, DX administered before ligation of the carotid arteries reduced loss in both CaM-KII and PKC activity evoked by ischemia.

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