SEQUENCE-ANALYSIS, EXPRESSION, AND DELETION OF A VACCINIA VIRUS GENE ENCODING A HOMOLOG OF PROFILIN, A EUKARYOTIC ACTIN-BINDING PROTEIN
SEQUENCE-ANALYSIS, EXPRESSION, AND DELETION OF A VACCINIA VIRUS GENE ENCODING A HOMOLOG OF PROFILIN, A EUKARYOTIC ACTIN-BINDING PROTEIN
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DOI：
10.1128/jvi.65.9.4598-4608.1991
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发表时间：
1991-09-01
影响因子：
5.4
通讯作者：
MOSS, B
中科院分区：
文献类型：
--
作者：
BLASCO, R;COLE, NB;MOSS, B
一个4500 bp的BamHI片段位于牛痘病毒基因组的HindIII A片段中，包含8个78至346个氨基酸的多肽的潜在编码区。含有133、346和125个密码子的开放阅读框分别与profilin（一种肌动蛋白结合蛋白）、3- β -羟基类固醇脱氢酶和Cu-Zn超氧化物歧化酶同源。序列比对表明，牛痘病毒与哺乳动物的谱比与其他已知真核生物的谱关系更密切。因此，研究了增殖素同源物在病毒复制周期中的表达及其可能的作用。用表达牛痘病毒谱蛋白的大肠埃希氏菌抗体证实了牛痘病毒感染哺乳动物细胞后，15 kda多肽的合成。蛋白质在细胞质中积累，但只有微量与高度纯化的病毒粒子相关。痘苗病毒突变体（菌株WR和IHD-J）的分离，几乎整个profilin基因被大肠杆菌gpt基因取代，表明该蛋白对传染性不是必需的。荧光显微镜观察到的牛痘病毒引起的肌动蛋白纤维的特征性变化发生在突变体感染的细胞中。此外，正如电子显微镜和传染性细胞内和细胞外病毒的产量所显示的，与肌动蛋白相关的事件，包括细胞内病毒向细胞周围移动、形成专门的微绒毛或释放成熟病毒粒子，并不需要病毒编码的增殖素同源物。
A 4,500-bp BamHI fragment, located within the HindIII A segment of the vaccinia virus genome, was found to contain eight potential coding regions for polypeptides of 78 to 346 amino acids. The open reading frames with 133, 346, and 125 codons were homologous to profilin (an actin-binding protein), 3-beta-hydroxysteroid dehydrogenase, and Cu-Zn superoxide dismutase, respectively. Sequence alignments indicated that the vaccinia virus and mammalian profilins were more closely related to each other than to known profilins of other eukaryotes. The expression and possible role of the prolifin homolog in the virus replicative cycle were therefore investigated. Antibody raised to Escherichia coli expressed vaccinia virus profilin was used to demonstrate the synthesis of the 15-kDa polypeptide at late times after vaccinia virus infection of mammalian cells. The protein accumulated in the cytoplasm, but only trace amounts remained associated with highly purified virions. The isolation of vaccinia virus mutants (in strains WR and IHD-J), with nearly the entire profilin gene replaced by the E. coli gpt gene, indicated that the protein is not essential for infectivity. The characteristic vaccinia virus-induced changes in actin fibers, seen by fluorescence microscopy, occurred in cells infected with the mutant. Moreover, the virus-encoded prolifin homolog was not required for actin-associated events, including intracellular virus movement to the periphery of the cell, formation of specialized microvilli, or release of mature virions, as shown by electron microscopy and yields of infectious intra- and extracellular virus.