The amino-terminal signal peptide on the porcine transmissible gastroenteritis coronavirus matrix protein is not an absolute requirement for membrane translocation and glycosylation.
The amino-terminal signal peptide on the porcine transmissible gastroenteritis coronavirus matrix protein is not an absolute requirement for membrane translocation and glycosylation.
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DOI：
10.1016/0042-6822(88)90581-8
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发表时间：
1988-08
期刊：
影响因子：
3.7
通讯作者：
Wesley R
中科院分区：
文献类型：
--
作者：
Kapke PA;Tung FY;Hogue BG;Brian DA;Woods RD;Wesley R
采用Maxam和吉尔伯特的方法对猪传染性胃肠炎冠状病毒（TGEV）基因组3′端前2601个碱基的cDNA克隆进行了测序，并鉴定了一个开放阅读框架，该框架产生的蛋白具有基质（M或E1）蛋白的特性。它位于核衣壳（N）基因的5′端，由12个碱基的基因间延伸区隔开。推导的M蛋白由262个氨基酸组成，分子量为29，544，具有中等疏水性，在中性pH下具有+7的净电荷。其34%的氨基酸序列与牛冠状病毒（BCV）的M蛋白同源，32%与小鼠肝炎冠状病毒（MHV）的同源，鸡传染性支气管炎冠状病毒（IBV）的阳性率为19%。从与BCV、MHV和IBV M蛋白的比对判断，TGEV M蛋白的氨基末端从病毒体包膜延伸54个氨基酸，而与之相比，BCV仅28个氨基酸，MHV 26个氨基酸，IBV 21个氨基酸。16个氨基末端氨基酸中的11个是疏水性的，并且该序列周围的带电氨基酸的位置表明前16个氨基酸包含用于膜插入的潜在可裂解的信号肽。在BCV、MHV或IBV的M蛋白中未发现类似序列。当来自感染细胞的mRNA或通过体外转录重建的M基因制备的RNA在微粒体存在下进行体外翻译时，M蛋白发生易位和糖基化。当通过翻译截短形式的M基因转录物制备没有氨基末端信号肽的蛋白质时，也发生了一些易位和糖基化，这表明TGEV M蛋白上的氨基末端信号肽不是膜易位的绝对要求。有趣的是，氨基末端肽没有出现在体外翻译过程中被切割的微粒体的存在下，这表明在病毒粒子组装的步骤可能需要适当的暴露的切割位点的信号肽酶。
cDNA clones mapping within the first 2601 bases of the 3′ end of the porcine transmissible gastroenteritis coronavirus (TGEV) genome were sequenced by the method of Maxam and Gilbert and an open reading frame yielding a protein having properties of the matrix (M or E1) protein was identified. It is positioned at the 5′ side of the nucleocapsid (N) gene from which it is separated by an intergenic stretch of 12 bases. The deduced M protein comprises 262 amino acids, has a molecular weight of 29,544, is moderately hydrophobic, and has a net charge of +7 at neutral pH. Thirty-four percent of its amino acid sequence is homologous with the M protein of the bovine coronavirus (BCV), 32% with that of the mouse hepatitis coronavirus (MHV), and 19% with that of the avian infectious bronchitis coronavirus (IBV). Judging from alignment with the BCV, MHV, and IBV M proteins, the amino terminus of the TGEV M protein extends 54 amino acids from the virion envelope which compares with only 28 for BCV, 26 for MHV, and 21 for IBV. Eleven of the sixteen amino-terminal amino acids are hydrophobic and the positions of charged amino acids around this sequence suggest that the first 16 amino acids comprise a potentially cleavable signal peptide for membrane insertion. A similar sequence is not found in the M proteins of BCV, MHV, or IBV. When mRNA from infected cells, or RNA prepared by in vitro transcription of the reconstructed M gene, was translated in vitro in the presence of microsomes, the M protein became translocated and glycosylated. When a protein without the amino-terminal signal peptide was made by translating a truncated version of the M gene transcript, some translocation and glycosylation also occurred suggesting that the amino-terminal signal peptide on the TGEV M protein is not an absolute requirement for membrane translocation. Interestingly, the amino-terminal peptide did not appear to be cleaved during in vitro translation in the presence of microsomes suggesting that a step in virion assembly may be required for proper exposure of the cleavage site to the signal peptidase.
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DOI：
10.1083/jcb.93.1.97
发表时间：
1982-04
期刊：
The Journal of cell biology
影响因子：
--
作者：
Fujiki Y;Hubbard AL;Fowler S;Lazarow PB
通讯作者：
Lazarow PB
影响因子：
3.8
作者：
GARWES, DJ;POCOCK, DH
通讯作者：
POCOCK, DH
影响因子：
5.4
作者：
ROSE, JK;GALLIONE, CJ
通讯作者：
GALLIONE, CJ
影响因子：
5.4
作者：
BUDZILOWICZ, CJ;WILCZYNSKI, SP;WEISS, SR
通讯作者：
WEISS, SR
DOI：
10.1073/pnas.83.12.4204
发表时间：
1986-06-01
影响因子：
11.1
作者：
MAKINO, S;STOHLMAN, SA;LAI, MMC
通讯作者：
LAI, MMC