Biochemical signal transmitted by Fc receptor for immunoglobulin G2a of a murine macrophage-like cell line, P388D1: mode of activation of adenylate cyclase mediated by immunoglobulin G2a binding proteins.
Biochemical signal transmitted by Fc receptor for immunoglobulin G2a of a murine macrophage-like cell line, P388D1: mode of activation of adenylate cyclase mediated by immunoglobulin G2a binding proteins.
复制标题
鼠巨噬细胞样细胞系 P388D1 的免疫球蛋白 G2a Fc 受体传递的生化信号：免疫球蛋白 G2a 结合蛋白介导的腺苷酸环化酶激活模式。
DOI：
10.1021/bi00363a032
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发表时间：
1986
期刊：
影响因子：
2.9
通讯作者：
Suzuki,T
中科院分区：
文献类型：
--
作者：
Fernandez-Botran,R;Suzuki,T
Department of Microbiology, University of Kansas Medical Center, Kansas City, Kansas 66103 Received November 13, 1985; Revised Manuscript Received April 7, 1986 abstract: The effects of immunoglobulin G2a binding proteins isolated from P388D! cells on adenylate cyclase of eye" cells were investigated to explore a potential role of Fc72a receptor in the activation of the adenylate cyclase system. Immunoglobulin G (IgG) binding proteins obtained from the detergent lysate of P388D! cells by affinity chromatography on IgG-Sepharose were separated into two fractions (denoted as IgG-Bl and IgG-B2) bySephadex G-100 gel Filtration in the presence of 6 M urea. Polyacrylamide gel electrophoretic analysis in thepresence of sodium dodecyl sulfate revealed that the major component in the IgG-Bl fraction was a protein of molecular weight near 50000, whereas the IgG-B2 fraction contained two major components of molecular weight near 25000 and 17 000. Both IgG-Bl and-B2 proteins can be inserted into liposome consisting of phosphatidylcholine and phosphatidylethanolamine. Liposomes containing IgG-Bl proteins effectively inhibited EA2a, but not EA2b, rosetting by either S49 or P388Di cells, suggesting their proper orientation within liposome, whereas IgG-B2-containing liposome failed to do so. Simultaneous fusion of the liposomes containing IgG-Bl and-B2 proteins with guanine nucleotide binding stimulatory (G/F) protein/Fc72aR-deFicient eye" cells resulted in the formation of the hybrid membrane whose adenylate cyclase responds toimmune complex formed with IgG2a-subclass antibody (IC2a) by about a 2.7-fold increase in the activity over the control (hybrid membrane between eye" cells and liposome containing no protein). The response appeared to be specific, since IC2b failed to stimulate the enzymatic activity of this hybrid membrane. Furthermore, IgG-Bl and-B2 proteins were able to confer their activating effects on the enzyme only in concert, since the fusion of liposomes containing either type of protein alone with eye" cells did not result in the activation of adenylate cyclase of eye" membrane. IgG-Bl and-B2 proteins could also confer their activating effects in concert to the enzyme in cholate-solubilized forms. Such activation was dependent on the concentration of IC^, suppressed by the chelating agent ethylene glycol bis (/3-aminoethyl ether)-./V,./V, Ar/, 7V-tetraacetic acid, and signiFicantlyinhibited by trifluoperazine, suggesting potential in-volvement of Ca2+ and calmodulin in the activating process. Since the activation of adenylate cyclase of eye" cells mediated by IgG-Bl and-B2 proteins was not augmented in vitro by either addition of NaF or deletion of GTP and since IgG-Bl and-B2 proteins inserted into liposome or in cholate-solubilized form had neither detectable GTPase activity nor a cholera toxin sensitive ADP-ribosylation site, the mechanism by which liposome-inserted or cholate-solubilized IgG-binding proteins confer their activating effect on eye" cell adenylate cyclase may be different from that mediated by G/F protein in a classical manner.
