Evidence that insulin activates casein kinase 2 in rat epididymal fat-cells and that this may result in the increased phosphorylation of an acid-soluble 22 kDa protein.
Casein kinase 2 activity as measured by phosphorylation of the peptide substrate Arg-Arg-Arg-Glu-Glu-Glu-Thr-Glu-Glu-Glu is increased by about 50% in extracts from insulin-treated epididymal fat-pads or isolated fat-cells after purification by Mono Q chromatography. Insulin acts to increase the Vmax. of the kinase. An acid-soluble protein with an apparent subunit molecular mass of about 22 kDa appears to be a substrate for casein kinase 2. The protein possesses a number of properties in common with the acid-soluble heat-stable 22 kDa protein which exhibits increased phosphorylation in rat adipose tissue exposed to insulin.
Diggle
T A
TA
Department of Biochemistry, University of Bristol Medical School, U.K.
Schmitz-Peiffer
C
C
Borthwick
A C
AC
Welsh
G I
GI
Denton
R M
RM
D000273:Adipose Tissue / Q000201:enzymology*; D000595:Amino Acid Sequence; D000818:Animals; D047388:Casein Kinases; D004789:Enzyme Activation / Q000187:drug effects; D004822:Epididymis; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010449:Peptide Mapping; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D007328:Insulin; D010750:Phosphoproteins; D011494:Protein Kinases; D047388:Casein Kinases