The effect of recombinant interleukin 4 upon protein kinase activities associated with murine and human B lymphocyte plasma membranes.
Exposure of plasma membranes isolated from high density resting murine B cells to recombinant IL-4 in the presence of gamma-[32P]-ATP promoted phosphorylation of a protein of Mr = 42,000. The 42 Kd protein kinase substrate could be detected in membranes prepared from low density B cells following a 24 h culture with lipopolysaccharide, but not in membranes prepared from B cells exposed to LPS for 48 h. Treatment of the cells with LPS resulted in the appearance of a number of new membrane-associated phosphoproteins. Treatment with the cytokine also resulted in the disappearance of a protein kinase substrate of Mr = 30,000 from phosphoprotein profiles of membranes prepared from cells exposed to LPS for 24 h. The 42 Kd structure appears to be a protein kinase substrate rather than possessing intrinsic phosphotransferase activity as judged from experiments employing 8-azido-gamma-[32P]-ATP as a photoaffinity label. No 42 Kd species was detectable using this reagent. Experiments employing identical protocols failed to reveal any enhanced or diminished phosphorylation of membrane-associated proteins in human peripheral blood B cells or in human B lymphoma cell lines.
McGarvie
G M
GM
Department of Biochemistry, University of Glasgow, Scotland, U.K.
Cushley
W
W
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001402:B-Lymphocytes / Q000201:enzymology*; D002453:Cell Cycle / Q000502:physiology; D002458:Cell Fractionation; D002462:Cell Membrane / Q000201:enzymology; D006801:Humans; D066298:In Vitro Techniques; D015847:Interleukin-4 / Q000502:physiology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D010750:Phosphoproteins / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology
D008070:Lipopolysaccharides; D008565:Membrane Proteins; D010750:Phosphoproteins; D011994:Recombinant Proteins; D015847:Interleukin-4; D000255:Adenosine Triphosphate; D011494:Protein Kinases