Insulin receptor autophosphorylation in BC/sub 3/H-1 whole cell assays is inhibited by the specific calmodulin inhibitors calmidazolium and W-7

Conference · Fri May 01 04:00:00 EDT 1987 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5904533

Arnold, T P; Pollet, R I

Recent reports suggest the involvement of Ca/sup + +/ and the Ca/sup + +/ binding protein calmodulin in the insulin stimulated receptor tyrosine kinase activity in cell free (adipocyte) phosphorylation systems. Working with the insulin-responsive well characterized muscle cell line BC/sub 3/H-1, they have investigated the effects of calmodulin antagonists on insulin receptor phosphorylation in cultured intact cells. BC/sub 3/H-1 myocytes were grown to confluency (10-12 days) then exposed to media containing /sup 32/P-orthophosphate for 24 hours (100 mCi/ml). Insulin treatment stimulated the phosphorylation of a 95K protein which is immunoprecipitable with antireceptor antibodies indicating insulin-induced phosphorylation of the insulin receptor beta subunit in vivo. This phosphorylation occurs rapidly within 30 minutes at physiologic insulin concentrations at 37/sup 0/C. Phosphorylation can also be stimulated by the B-10 anti-insulin receptor antibody (1:500). Pretreatment of cells for 30 min with 1uM calmidazolium (R24571) and 10nM W-7 (n-(6-AminoHexyl)-s-chloro-1-naphalenesulfonamide) each significantly inhibited insulin-stimulated phosphorylation. This would suggest that calmodulin may play a role in mediation of the insulin receptor tyrosine kinase activity in the BC/sub 3/H-1 myocyte.

• Research Organization: Univ. of South Florida College of Medicine, Tampa
• OSTI ID: 5904533
• Report Number(s): CONF-870644-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 46:6
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CALMODULIN
CELL CULTURES
CHEMICAL REACTIONS
DAYS LIVING RADIOISOTOPES
ENZYME ACTIVITY
ENZYMES
HORMONES
INHIBITION
INSULIN
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGHT NUCLEI
MEMBRANE PROTEINS
MUSCLES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PEPTIDE HORMONES
PHOSPHATES
PHOSPHORUS 32
PHOSPHORUS COMPOUNDS
PHOSPHORUS ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHORYLATION
PHOSPHOTRANSFERASES
PROTEINS
RADIOISOTOPES
REACTION KINETICS
RECEPTORS
TRACER TECHNIQUES
TRANSFERASES