文章基本信息

标题：The Effects of Cholesterol-3-sulfate (CH-3S) on the Phosphorylation of Human C3a (hC3a) in Vitro and on the Ability of hC3a to Induce Vascular Permeability in Rats
本地全文：下载
作者：Fumitaka Kawakami ; Masaki Ito ; Yuya Matsuda 等
期刊名称：Biological and Pharmaceutical Bulletin
印刷版ISSN：0918-6158
电子版ISSN：1347-5215
出版年度：2004
卷号：27
期号：3
页码：282-287
DOI：10.1248/bpb.27.282
出版社：The Pharmaceutical Society of Japan
摘要：The phosphorylation of human C3a (hC3a, anaphylatoxin) by two distinct protein kinases (PKA and CK-I) and the effect of cholesterol-3-sulfate (CH-3S) on this phosphorylation were biochemically investigated in vitro . It was found that (i) hC3a functions as a phosphate acceptor for PKA and CK-I, but not for CK-II; (ii) the CK-I-mediated phosphorylation of hC3a requires the presence of 3 μ M CH-3S in a manner similar to the phosphorylation of HMG1 (CH-3S-binding protein) by CK-I; and (iii) CH-3S inhibits the PKA-mediated phosphorylation of hC3a in a dose-dependent manner (ID₅₀=approx. 2 μ M ). As expected, hC3a containing high levels of Arg- and Lys-residues stimulated approx. 3-fold CK-II activity (phosphorylation of α-casein) in vitro . However, no significant effect of hC3a on CK-II activity was observed when hC3a was preincubated with CH-3S or fully phosphorylated by PKA in vitro . Furthermore, preincubation of hC3a with CH-3S diminished the ability of hC3a to induce vascular permeability in rats. The results provided here suggest that (i) hC3a is a CH-3S-binding protein; and (ii) CH-3S functions as a potent inhibitor for its physiological activities, including phosphorylation by PKA and CK-I, in vitro .
关键词：cAMP-dependent protein kinase;casein kinase I;casein kinase II;human C3a;cholesterol-3-sulfate;sulfatide