Type II cAMP-dependent protein kinase is associated with the rabbit kidney brush border membranes.
Photolabelling with 32P-8-azido-cAMP identified a major cAMP-binding protein (54 kDa) in isolated rabbit renal apical membranes, whose labelling was competitively inhibited by cAMP. Membrane associated cAMP-binding polypeptides were extensively purified by affinity chromatography on cAMP-Sepharose. The 54 kDa polypeptide represented 70-80% of the total protein eluted with cAMP. This protein was rapidly phosphorylated by the catalytic subunit of cAMP-dependent protein kinase, with a shift in its apparent mobility on SDS-PAGE to Mr 56/58,000. The phosphopeptide maps of autophosphorylated rat skeletal muscle RII and rabbit kidney 56/58 kDa proteins were essentially identical. Western immuno-blot analysis, using antibodies generated against purified rat RI and RII, indicated preferential cross-reactivity of rabbit kidney 54 kDa protein with anti-RII antibodies. The data demonstrates the specific association of the regulatory subunit of type II cAMP dependent protein kinase with rabbit renal brush border membranes.
Shenolikar
S
S
Department of Pharmacology, University of Texas Medical School at Houston 77025.
Fischer
K
K
Chang
L
L
Weinman
E J
EJ
D000818:Animals; D015153:Blotting, Western; D000242:Cyclic AMP / Q000378:metabolism; D007668:Kidney / Q000201:enzymology* / Q000648:ultrastructure; D008871:Microvilli / Q000201:enzymology; D010449:Peptide Mapping; D011494:Protein Kinases / Q000302:isolation & purification*; D011817:Rabbits
D000242:Cyclic AMP; D011494:Protein Kinases