胶质细胞成熟因子与胶质细胞膜的相互作用。

Interaction of glia maturation factor with the glial cell membrane.

作者信息

Ito J, Kato T, Yamakawa Y, Kato H, Sakazaki Y, Lim R, Tanaka R

出版信息

Brain Res. 1982 Jul 15;243(2):309-14. doi: 10.1016/0006-8993(82)90254-2.

Abstract

Glia maturation factor (GMF) immobilized on agarose beads retained the same mitogenic and morphological transforming activities as free GMF when tested on glioblasts. The exposure of glioblasts to immobilized GMF for 5 min provoked the initiation of DNA synthesis and maximal stimulation was obtained within 30 min. Thiol-reducing agents, such as dithiothreitol and cysteine, increased the biological activity of GMF. These data suggest the presence of a surface receptor to GMF on the glioblasts, while the reduction of the thiol group(s) in GMF promotes the binding to its receptor. Repeated use of immobilized GMF decreased both the mitogenic and the morphological transforming activities. Immobilized GMF used for the third time lost its biological activity. This implies the existence of a certain kind of degradation system such as a proteolytic enzyme located close to the GMF receptor on the glial cell surface.

摘要

固定在琼脂糖珠上的胶质细胞成熟因子（GMF），在对胶质母细胞瘤细胞进行测试时，保留了与游离GMF相同的促有丝分裂和形态转化活性。将胶质母细胞瘤细胞暴露于固定化GMF 5分钟可引发DNA合成的启动，并在30分钟内获得最大刺激。硫醇还原剂，如二硫苏糖醇和半胱氨酸，可提高GMF的生物活性。这些数据表明胶质母细胞瘤细胞表面存在GMF的表面受体，而GMF中硫醇基团的还原促进了其与受体的结合。重复使用固定化GMF会降低促有丝分裂和形态转化活性。第三次使用的固定化GMF失去了其生物活性。这意味着存在某种降解系统，如位于胶质细胞表面GMF受体附近的蛋白水解酶。