Brown D A, Simoni R D
Proc Natl Acad Sci U S A. 1984 Mar;81(6):1674-8. doi: 10.1073/pnas.81.6.1674.
Using a cell line, C100, that overproduces 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase; EC 1.1.1.34) 100-fold, we have studied the synthesis and insertion of this protein into the endoplasmic reticulum. The enzyme is synthesized on membrane-bound polysomes. It is cotranslationally but not post-translationally inserted into dog pancreatic microsomes. This cotranslational insertion is dependent upon signal recognition particle. HMG-CoA reductase is glycosylated with an oligosaccharide(s) of the "high-mannose" type sensitive to endo-beta-D-N-acetylglucosaminidase H. Partial determination of the NH2-terminal amino acid sequence of the in vitro translation product and the mature polypeptide indicate they are the same and demonstrate there is no cleavage of an NH2-terminal signal sequence.
利用一种能过量产生3-羟基-3-甲基戊二酰辅酶A还原酶（HMG-CoA还原酶；EC 1.1.1.34）达100倍的细胞系C100，我们研究了该蛋白在内质网中的合成与插入过程。该酶在膜结合多核糖体上合成。它是共翻译插入而非翻译后插入犬胰腺微粒体。这种共翻译插入依赖于信号识别颗粒。HMG-CoA还原酶被“高甘露糖”型寡糖糖基化，这种寡糖对内切β-D-N-乙酰葡糖胺酶H敏感。对体外翻译产物和成熟多肽的NH2末端氨基酸序列的部分测定表明它们是相同的，并且证明不存在NH2末端信号序列的切割。
