TY - JOUR
T1 - Calcium-dependent regulation of glycogen synthase activity in a muscle glycogen particle
AU - Srivastava, Ashok K.
AU - Khatra, Balwant S.
AU - Soderling, Thomas R.
N1 - Funding Information:
1 This work has been supported by the National Institutes of Health Grant AM 1’7808. 2 Abbreviations used: CAMP, adenosine 3’,5’-monophosphate; EGTA, ethylene glycol bis(&aminoethyl ether)-N,N’-tetraacetic acid; BSA, bovine serum albumin. ATP-y-s, Adenosine 5’-0 (3-thiotriphosphate).
PY - 1980/12
Y1 - 1980/12
N2 - The calcium-dependent inactivation of glycogen synthase in an isolated glycogen-protein complex (glycogen pellet) from rabbit skeletal muscle has been investigated. Addition of 1 mm Ca2+, 10 mm Mg2+, and 1 mm ATP-γ-S to a concentrated suspension of glycogen pellet resulted in a rapid activation of glycogen phosphorylase concomitant with an inactivation of glycogen synthase. These conversion reactions were blocked by ethylene glycol bis(β-aminoethyl ether) N, N′-tetraacetic acid or by pretreatment of the complex with an antiserum to purified phosphorylase kinase. These data suggest that in the glycogen-protein complex, which may be a functional unit of glycogen metabolism in vivo, phosphorylase kinase can catalyze a Ca2+-dependent activation of glycogen phosphorylase synchronized with an inactivation of glycogen synthase. If under similar conditions phosphoprotein phosphatase activity was assayed using exogenous [32P]phosphorylase, there was an apparent inactivation of the phosphatase. Evidence is presented that this apparent inactivation of phosphatase was due to an accumulation of endogenous phosphorylase a which acted as an inhibitor to the exogenous [32P]-phosphorylase.
AB - The calcium-dependent inactivation of glycogen synthase in an isolated glycogen-protein complex (glycogen pellet) from rabbit skeletal muscle has been investigated. Addition of 1 mm Ca2+, 10 mm Mg2+, and 1 mm ATP-γ-S to a concentrated suspension of glycogen pellet resulted in a rapid activation of glycogen phosphorylase concomitant with an inactivation of glycogen synthase. These conversion reactions were blocked by ethylene glycol bis(β-aminoethyl ether) N, N′-tetraacetic acid or by pretreatment of the complex with an antiserum to purified phosphorylase kinase. These data suggest that in the glycogen-protein complex, which may be a functional unit of glycogen metabolism in vivo, phosphorylase kinase can catalyze a Ca2+-dependent activation of glycogen phosphorylase synchronized with an inactivation of glycogen synthase. If under similar conditions phosphoprotein phosphatase activity was assayed using exogenous [32P]phosphorylase, there was an apparent inactivation of the phosphatase. Evidence is presented that this apparent inactivation of phosphatase was due to an accumulation of endogenous phosphorylase a which acted as an inhibitor to the exogenous [32P]-phosphorylase.
UR - http://www.scopus.com/inward/record.url?scp=0019274780&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0019274780&partnerID=8YFLogxK
U2 - 10.1016/0003-9861(80)90110-1
DO - 10.1016/0003-9861(80)90110-1
M3 - Article
C2 - 6781409
AN - SCOPUS:0019274780
SN - 0003-9861
VL - 205
SP - 291
EP - 296
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
IS - 2
ER -