Phosphorylation and activation of calcineurin by glycogen synthase (casein) kinase-1 and cyclic AMP-dependent protein kinase

Conference · Thu May 01 04:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:7119665

Singh, T J; Wang, J H

Calcineurin is a phosphoprotein phosphatase that is activated by divalent cations and further stimulated by calmodulin. In this study calcineurin is shown to be a substrate for both glycogen synthase (casein) kinase-1 (CK-1) and cyclic AMP-dependent protein kinase (A-kinase). Either kinase can catalyze the incorporation of 1.0-1.4 mol /sup 32/P/mol calcineurin. Analysis by SDS-PAGE revealed that only the ..cap alpha.. subunit is phosphorylated. Phosphorylation of calcineurin by either kinase leads to its activation. Using p-nitrophenyl phosphate as a substrate the authors observed a 2-3 fold activation of calcineurin by either Mn/sup 2 +/ or Ni/sup 2 +/ (in the presence or absence of calmodulin) after phosphorylation of calcineurin by either CK-1 or A-kinase. In the absence of Mn/sup 2 +/ or Ni/sup 2 +/ phosphorylated calcineurin, like the nonphosphorylated enzyme, showed very little activity. Ni/sup 2 +/ was a more potent activator of phosphorylated calcineurin compared to Mn/sup 2 +/. Higher levels of activation (5-8 fold) of calcineurin by calmodulin was observed when phosphorylated calcineurin was pretreated with Ni/sup 2 +/ before measurement of phosphatase activity. These results indicate that phosphorylation may be an important mechanism by which calcineurin activity is regulated by Ca/sup 2 +/.

• Research Organization: Univ. of Calgary, Alberta
• OSTI ID: 7119665
• Report Number(s): CONF-8606151-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:6
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALINE EARTH METAL COMPOUNDS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL FUNCTIONS
CALCIUM COMPOUNDS
CATIONS
CHARGED PARTICLES
CHEMICAL REACTIONS
DAYS LIVING RADIOISOTOPES
ELECTROPHORESIS
ENZYME ACTIVITY
ENZYME REACTIVATION
ENZYMES
ESTERASES
FUNCTIONS
HYDROLASES
IONS
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGHT NUCLEI
MANGANESE COMPOUNDS
NICKEL COMPOUNDS
NUCLEI
ODD-ODD NUCLEI
PHOSPHATASES
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHORYLATION
PHOSPHOTRANSFERASES
RADIOISOTOPES
REACTION KINETICS
TRACER TECHNIQUES
TRANSFERASES
TRANSITION ELEMENT COMPOUNDS