Signal recognition particle arrests elongation of nascent secretory and membrane proteins at multiple sites in a transient manner.
Signal recognition particle arrests elongation of nascent secretory and membrane proteins at multiple sites in a transient manner.
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信号识别颗粒以瞬时方式阻止多个位点新生分泌蛋白和膜蛋白的伸长。
DOI：
10.1016/s0021-9258(19)75691-9
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
M. Haeuptle
中科院分区：
文献类型：
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作者：
J. Lipp;B. Dobberstein;M. Haeuptle
信号识别颗粒(SRP)可以将新生分泌物和膜蛋白定位于内质网。在小麦胚芽无细胞系统中，SRP阻止新生链的延长，直到翻译复合体与内质网膜对接，在内质网膜上SRP与对接蛋白的相互作用导致新生链停滞的释放。对于两种分泌蛋白，已经确定了70个氨基酸的停滞肽(Walter，P.，Ibrahimi，I.和Blobel，G.(1981)J.Cell Biol)。91,545-550；Meyer，D.I.，Krause，E.和Dobberstein，B.(1982)自然297,647-650)。利用体外转录-翻译耦合系统，我们分析了SRP停滞和两种分泌蛋白溶菌酶和粒细胞-巨噬细胞集落刺激因子以及膜蛋白不变链的产物。SRP在多个位置阻止了所有三种蛋白质的伸长，导致了被阻止的多肽的梯形。随着翻译时间的延长，滞留多肽的大小逐渐增大，约40min后基本形成全长的前肽。这表明SRP是一过性的，而不是稳定的。当加入微粒体后，SRP抑制被释放，所有被阻断的多肽都可以被追逐成成熟蛋白或全长前体。
The signal recognition particle (SRP) has been shown to target nascent secretory and membrane proteins to the endoplasmic reticulum. In the wheat germ cell-free system, SRP arrests the elongation of the nascent chains until the translational complex is docked to the endoplasmic reticulum membrane where the interaction between SRP and docking protein causes a release of the nascent chain arrest. For two secretory proteins, arrested peptides of 70 amino acids have been identified (Walter, P., Ibrahimi, I., and Blobel, G. (1981) J. Cell Biol. 91, 545-550; Meyer, D. I., Krause, E., and Dobberstein, B. (1982) Nature 297, 647-650). By using an in vitro coupled transcription-translation system, we have analyzed SRP arrest and the resulting peptides of the two secretory proteins lysozyme and granulocyte-macrophage colony-stimulating factor and the membrane protein invariant chain. SRP arrested the elongation of all three proteins at multiple sites, giving rise to ladders of arrested peptides. The size of the arrested peptides increased with the time of translation, resulting in mostly full-length pre-peptides after about 40 min. This suggests that SRP arrest in transient rather than stable. Upon addition of microsomes, the SRP arrest was released, and all the blocked peptides could be chased into mature proteins or full-length precursors.