Expression of a G-protein beta subunit-related gene during lymphocyte activation.
Using a subtractive strategy, we have cloned an activation-related gene from a human B cell cDNA library. Sequence analysis revealed that this gene was identical to H12.3, a gene belonging to an expanding family of guanine nucleotide-binding protein beta subunits. The expression of H12.3 was inducible in the late phase of mitogen-stimulated T and B cells. In T cells, IL-2 and IL-4 by themselves had no direct effect on the expression of H12.3, but they could augment the level of steady-state H12.3 mRNA stimulated by phytohemagglutinin. On the other hand, IFN-gamma and IL-6 had no obvious effect on the expression in B cells with or without Staphylococcus aureus Cowan I-stimulation. Cyclosporin A, a strong immunosuppressant, inhibited the mitogen-stimulated expression of H12.3, but rapamycin, another such agent, did not. In synchronized Jurkat cells, the expression of H12.3 had no cell cycle-dependent decrease in S and G2/M phase, while cyclin E, which controls the progression of the cell cycle in late G1 phase, did show a periodic expression pattern. The results suggest that H12.3 might be involved in regulation of lymphocyte activation.
Shan
X
X
Laboratory of Nephrology and Transplantation Immunology, Notre-Dame Hospital Research Center, Montreal, Quebec, Canada.
Luo
H
H
Houle
B
B
Wu
J
J
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002453:Cell Cycle; D002478:Cells, Cultured; D003001:Cloning, Molecular; D016572:Cyclosporine / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D008213:Lymphocyte Activation; D051379:Mice; D010835:Phytohemagglutinins / Q000494:pharmacology; D011090:Polyenes / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D020123:Sirolimus; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D014407:Tumor Cells, Cultured
D010835:Phytohemagglutinins; D011090:Polyenes; D012333:RNA, Messenger; D016572:Cyclosporine; D019204:GTP-Binding Proteins; D020123:Sirolimus