Effect of G-protein on granule release from basophils

Research Project

Project/Area Number	07807060
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Respiratory organ internal medicine
Research Institution	Tohoku University
Principal Investigator	KAKUTA Yasunori Tohoku University Hospital, Assistant, 医学部・附属病院, 助手 (80142933)
Co-Investigator(Kenkyū-buntansha)	YAMAUCHI Kohei Icuate Medicol University, Associate Professor, 医学部, 助教授 (20200579)
Project Period (FY)	1995 – 1996
Project Status	Completed (Fiscal Year 1996)
Budget Amount *help	¥2,100,000 (Direct Cost: ¥2,100,000) Fiscal Year 1996: ¥1,100,000 (Direct Cost: ¥1,100,000) Fiscal Year 1995: ¥1,000,000 (Direct Cost: ¥1,000,000)
Keywords	Basophils / G-protein / Protein Kinase C / Protein kinase C / G蛋白 / 受容体の凝集 / 細胞骨格 / カクチン
Research Abstract	We have previously demonstrated that intracellular application of 1 muM Ca^<2+> induces granule release from human basophils. This concentration of Ca^<2+> is rather high as compared with physiological concentration, suggesting that some other factors promote Ca^<2+> induced granule release. We have observed that certain GTP binding proteins (G-proteins) and protein kinase C modulate Ca^<2+> dependent degranulation. In this study we examined the gene expression of a G-protein, rab 3A,since this protein has been reported to induce granule release from rodent mast cells. In addition, we determined the expression of isozymes of Ca^<2+> dependent protein kinase C.We used RT-PCR and Southern blot analysis to examine the expression of rab 3A and beta-actin, which was used as a house-keeping gene. Rab 3A gene was markedly expressed in peripheral blood mononuclear cells whereas it was not appreciably observed in human basophils. In contrast, beta-actin was definitely expressed in both groups, indicating that rab 3A gene is not appreciably expressed in human basophils. We then examined the expression of isozymes of Ca^<2+> dependent protein kinase C,that is alpha, beta and gamma, using monoclonal antibodies. We observed that beta isozyme was strongly expressed whereas neither alpha nor gamma isozyme was appreciably found in human basophils. beta isozyme has been reported to promote degranulation in a rat basophilic leukemia cell line (RBL2H3). In conclusion, the G-protein rab 3A is not involved in granule release, but protein kinase C beta may modulate Ca^<2+> induced degranulation in human basophils.