TY - JOUR
T1 - Calmodulin-dependent glycogen synthase kinase
T2 - Identification in liver of normal and phosphorylase kinase-deficient rats
AU - Schworer, Charles M.
AU - Payne, M. Elizabeth
AU - Williams, Alan T.
AU - Soderling, Thomas R.
N1 - Funding Information:
‘Supported in part by Grant AM 17808 from the National Institutes of Health. ‘Recipient of postdoctoral fellowship AM 06449 from the National Institutes of Health. To whom all correspondence should be addressed. a Present address: Laboratory of Molecular Cardiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Building 10, Room ‘7RO9, Bethesda, Maryland 20205.
PY - 1983/7/1
Y1 - 1983/7/1
N2 - We have purified a calmodulin-dependent glycogen synthase kinase from livers of normal and phosphorylase kinase-deficient (gsd/gsd) rats. No differences between normal and gsd/gsd rats were apparent in either (a) the ability of liver extracts to phosphorylate exogenous glycogen synthase in a Ca2+- and calmodulin-dependent manner or (b) the purification of the calmodulin-dependent synthase kinase. Although extracts from rat liver, when compared to rabbit liver extracts, had a significantly reduced ability to phosphorylate exogenous synthase, the calmodulin-dependent synthase kinase could be purified from rat liver using a protocol identical to that described for rabbit liver. Moreover, the synthase kinase purified from rat liver had properties very similar to those of the rabbit liver enzyme. The enzyme was completely dependent on calmodulin for activity against glycogen synthase, was unable to phosphorylate phosphorylase b, catalyzed the rapid incorporation of 0.4 mol phosphate/mol of glycogen synthase subunit, selectively phosphorylated sites 1b and 2 in the glycogen synthase molecule, had a Stokes' radius of about 70 Å, and appeared to be composed of subunits of Mr 56,000 and 57,000. These observations led us to conclude that (1) calmodulin-dependent glycogen synthase kinase is distinct from other kinases previously described and (2) the rat liver kinase and the rabbit liver kinase are very similar enzymes.
AB - We have purified a calmodulin-dependent glycogen synthase kinase from livers of normal and phosphorylase kinase-deficient (gsd/gsd) rats. No differences between normal and gsd/gsd rats were apparent in either (a) the ability of liver extracts to phosphorylate exogenous glycogen synthase in a Ca2+- and calmodulin-dependent manner or (b) the purification of the calmodulin-dependent synthase kinase. Although extracts from rat liver, when compared to rabbit liver extracts, had a significantly reduced ability to phosphorylate exogenous synthase, the calmodulin-dependent synthase kinase could be purified from rat liver using a protocol identical to that described for rabbit liver. Moreover, the synthase kinase purified from rat liver had properties very similar to those of the rabbit liver enzyme. The enzyme was completely dependent on calmodulin for activity against glycogen synthase, was unable to phosphorylate phosphorylase b, catalyzed the rapid incorporation of 0.4 mol phosphate/mol of glycogen synthase subunit, selectively phosphorylated sites 1b and 2 in the glycogen synthase molecule, had a Stokes' radius of about 70 Å, and appeared to be composed of subunits of Mr 56,000 and 57,000. These observations led us to conclude that (1) calmodulin-dependent glycogen synthase kinase is distinct from other kinases previously described and (2) the rat liver kinase and the rabbit liver kinase are very similar enzymes.
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U2 - 10.1016/0003-9861(83)90191-1
DO - 10.1016/0003-9861(83)90191-1
M3 - Article
C2 - 6307155
AN - SCOPUS:0020533387
SN - 0003-9861
VL - 224
SP - 77
EP - 86
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
IS - 1
ER -