Robinson A, Westwood O M, Austen B M
Department of Surgery, St. George's Hospital Medical School, Tooting, London, U.K.
Biochem J. 1990 Feb 15;266(1):149-56. doi: 10.1042/bj2660149.
The mechanisms whereby isolated or synthetic signal peptides inhibit processing of newly synthesized prolactin in microsome-supplemented lysates from reticulocytes and wheat-germ were investigated. At a concentration of 5 microM, a consensus signal peptide reverses the elongation arrest imposed by the signal-recognition particle (SRP), and at higher concentrations in addition inhibits elongation of both secretory and non-secretory proteins. A photoreactive form of a synthetic signal peptide cross-links under u.v. illumination to the 54 kDa and 68 kDa subunits of SRP, whereas the major cross-linked protein produced after photoreaction of rough microsomes is of 45 kDa. As SRP-mediated elongation arrest is unlikely to be essential for translocation, it is suggested that signal peptides may interact with components other than SRP in the translation system in vitro.
研究了分离的或合成的信号肽抑制来自网织红细胞和麦胚的微粒体补充裂解物中新合成催乳素加工的机制。在5微摩尔的浓度下，一种共有信号肽可逆转信号识别颗粒（SRP）施加的延伸停滞，而在更高浓度下，还会抑制分泌性和非分泌性蛋白质的延伸。一种合成信号肽的光反应形式在紫外线照射下与SRP的54 kDa和68 kDa亚基交联，而粗面微粒体光反应后产生的主要交联蛋白为45 kDa。由于SRP介导的延伸停滞不太可能是转运所必需的，因此表明信号肽可能在体外翻译系统中与SRP以外的成分相互作用。
