Autographa californica multiple nucleopolyhedrovirus and Choristoneura fumiferana multiple nucleopolyhedrovirus v-cath genes are expressed as pre-proenzymes
Autographa californica multiple nucleopolyhedrovirus and Choristoneura fumiferana multiple nucleopolyhedrovirus v-cath genes are expressed as pre-proenzymes
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DOI：
10.1099/vir.0.007740-0
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发表时间：
2009-04-01
影响因子：
3.8
通讯作者：
Krell, Peter J.
中科院分区：
文献类型：
--
作者：
Hodgson, Jeffrey J.;Arif, Basil M.;Krell, Peter J.
杆状病毒v-cath表达的cathelpsin（V-CATH）缺乏典型的靶向信号，其细胞内加工和运输知之甚少。苜蓿银纹夜蛾多核型多角体病毒（AcMNPV）、烟羽卷蛾多核型多角体病毒（CfMNPV）和大多数其他α杆状病毒组I核型多角体病毒的组织蛋白酶具有高度保守的N-末端，其含有重叠的胰凝乳蛋白酶切割（Y-11）和肉豆蔻酰化（G（12））基序，这表明蛋白水解信号肽切割以产生proV-CATH和随后的酰化。为了确定V-CATH的蛋白水解N-末端加工，将血凝素表位编码标签融合到AcMNPV和CfMNPV v-cath的5'和/或3'末端。免疫印迹分析表明，一个小的N-末端肽被切割的两种病毒，表明V-导管表达为前酶原。这两种病毒同源物经历类似的蛋白水解加工，但具有不同的糖基化或其他翻译后修饰。AcMNPV V-CATH-DsRED融合蛋白与含HDEL基序的绿色荧光蛋白共定位于内质网。基于这些发现，preproV-CATH加工和贩运机制的假设。
Intracellular processing and trafficking of the baculovirus v-cath expressed cathelpsin (V-CATH), which lacks canonical targeting signals, are poorly understood. The cathepsins of Autographa californica multiple nucleopolyhedrovirus (AcMNPV), Choristoneura fumiferana multiple nucleopolyhedrovirus (CfMNPV) and most other alphabaculovirus group I nucleopolyhedroviruses have well-conserved N-termini containing overlapping chymotrypsin-cleavage (Y-11) and myristoylation (G(12)) motifs, which are suggestive of proteolytic signal-peptide cleavage to generate proV-CATH and subsequent acylation. To determine proteolytic N-terminal processing of V-CATH, haemagglutinin epitope-coding tags were fused to the 5' and/or 3' ends of AcMNPV and CfMNPV v-cath. Immunoblot analysis suggested that a small N-terminal peptide is cleaved for both viruses, indicating that v-cath is expressed as a pre-proenzyme. The two viral homologues undergo similar proteolytic processing, but have different glycosylation or other post-translational modifications. An AcMNPV V-CATH-DsRED fusion protein co-localized to the endoplasmic reticulum with an HDEL motif-containing green fluorescent protein. Based on these findings, preproV-CATH processing and trafficking mechanisms are postulated.