title: Translocation of protein kinase C during membrane immunoglobulin-mediated transmembrane signaling in B lymphocytes.
abstract: Previous studies have implicated a role for protein kinase C (PKC) in transmembrane signal transduction by B cell surface immunoglobulin (Ig). Specifically, the pharmacologic PKC activator phorbol myristate acetate mimics the biologic effects of mIg cross-linking ligands, and cross-linking of membrane Ig (mIg) induces polyphosphoinositide hydrolysis generating diacylglycerol, a potent activator of PKC. Studies described here additionally implicate PKC in mIg-mediated signaling by demonstrating rapid translocation of activatable PKC (PKCa) from cytosol to Triton-soluble membrane fractions after cross-linking of cell surface IgM or IgD. This response, which is also induced by phorbol myristate acetate and lipolysaccharide, is detectable within 1 min of mIg cross-linking and is followed within 4 min by additional translocation of PKCa to a Triton-insoluble particulate compartment. The ability of dbcAMP plus theophylline to inhibit polyphosphoinositide hydrolysis, PKCa translocation, and the B cell's subsequent biological response suggests that these events may be causally related.
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D000911:Antibodies, Monoclonal / Q000276:immunology; D001402:B-Lymphocytes / Q000201:enzymology* / Q000502:physiology / Q000648:ultrastructure; D003994:Bucladesine / Q000494:pharmacology; D002451:Cell Compartmentation; D002462:Cell Membrane / Q000502:physiology; D007072:Immunoglobulin D / Q000378:metabolism; D007075:Immunoglobulin M / Q000378:metabolism; D051379:Mice; D010716:Phosphatidylinositols / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism*; D011947:Receptors, Antigen, B-Cell / Q000502:physiology*; D013806:Theophylline / Q000494:pharmacology
chemical_list: D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D007072:Immunoglobulin D; D007075:Immunoglobulin M; D010716:Phosphatidylinositols; D011947:Receptors, Antigen, B-Cell; D003994:Bucladesine; D013806:Theophylline; D011493:Protein Kinase C