The COOH-terminal ends of internal signal and signal-anchor sequences are positioned differently in the ER translocase.
The COOH-terminal ends of internal signal and signal-anchor sequences are positioned differently in the ER translocase.
复制标题
内部信号和信号锚定序列的COOH末端在ER转运酶中的位置不同。
DOI：
10.1083/jcb.126.5.1127
复制
发表时间：
1994-09
影响因子：
7.8
通讯作者：
von Heijne, G
中科院分区：
文献类型：
--
作者：
Nilsson, I;Whitley, P;von Heijne, G
信号肽（SPs）将蛋白质靶向分泌途径，一旦内质网中的转位酶参与，就会从新生链上切割出来。信号锚定（SA）序列也与内质网转座酶短暂地相互作用，但不会被裂解，并向外移动，成为永久的膜锚定位点。SP和SA序列之间的一个明显区别是后者的疏水区（h区）相当长。为了研究SP/SA序列与ER转位酶之间的相互作用，我们构建了长度从8到29个残基不等的聚亮氨酸h区信号序列，并利用一种新的测定方法（测量h区cooh末端与低聚糖转移酶活性位点之间距离所需的最小氨基酸数量）和一种测定信号肽酶催化裂解效率的测定方法，确定了它们在转位酶中的位置。我们的研究结果表明SP和SA序列在ER转位酶中的位置不同。
Signal peptides (SPs) target proteins to the secretory pathway and are cleaved from the nascent chain once the translocase in the ER has been engaged. Signal-anchor (SA) sequences also interact transiently with the ER translocase, but are not cleaved and move laterally out of the translocase to become permanent membrane anchors. One obvious difference between SP and SA sequences is the considerably longer hydrophobic regions (h regions) of the latter. To study the interaction between SP/SA sequences and the ER translocase, we have constructed signal sequences with poly-Leu h regions ranging in length from 8 to 29 residues and have characterized their locations within the translocase using both a new assay that measures the minimum number of amino acids needed to span the distance between the COOH-terminal end of the h region and the active site of the oligosaccharyl transferase enzyme and an assay where the efficiency of signal peptidase catalyzed cleavage is measured. Our results suggest that SP and SA sequences are positioned differently in the ER translocase.