Biology of Circoviruses

圆环病毒是一种小的、无包膜的二十面体病毒，是几个动物物种的重要病原体。鸡传染性贫血是由一种名为鸡贫血病毒(CAV)的圆环病毒引起的。在集约化家禽养殖期间控制CAV的暴发是代价高昂且具有破坏性的。圆环病毒基因组很小，从1.7-2.3kb到圆形，这就是这个科的名字。CAV仅编码3个开放阅读框(ORF)。病毒在鸡中的致病性是由于一个单一的开放阅读框架，命名为病毒蛋白3(VP3)，它导致感染细胞的广泛凋亡，是病毒有效复制所必需的。为了了解CAV-VP3是如何诱导细胞死亡的，我们课题组纯化了与该蛋白相关的细胞蛋白复合体，发现CAV-VP3与后期促进复合体/环体(APC/C)结合。包括乳头瘤病毒、腺病毒、疱疹病毒、痘病毒和圆环病毒在内的几种不同类型的病毒都被证明具有结合和灭活APC/C的蛋白质。尽管这些广泛的病毒已经收敛地进化出抑制APC/C的策略，但这种相互作用在病毒复制过程中的功能重要性尚不清楚。因此，对CAV生物学的继续研究可以为分子病毒学和细胞生物学的一般机制提供基本的见解。

Circoviruses are small, non-enveloped icosahedral viruses that are important pathogens of several animal species. Infectious chicken anemia, is caused by a circovirus called chicken anemia virus (CAV). Controlling outbreaks of CAV during intensive poultry farming is costly and disruptive. Circovirus genomes are small, ranging between 1.7-2.3 kb and circular, which gives the family its name. CAV encodes only 3 open reading frames (ORFs). Pathogenicity of the virus in chickens is due to a single ORF, designated viral protein 3 (VP3), which causes extensive apoptosis in infected cells and is required for efficient viral replication. In order to understand how CAV-VP3 induces cell death, our group purified the cellular protein complexes associated with this protein and found that CAV-VP3 binds to the anaphase promoting complex/cyclosome (APC/C). Several diverse types of virus including Papillomavirus, Adenovirus, Herpesvirus, Poxvirus and Circovirus have all been shown to have proteins that bind and inactivate the APC/C. Although this wide range of viruses have convergently evolved strategies to inhibit the APC/C, the functional importance of this interaction during viral replication is unknown. Continued study of the biology of CAV can therefore provide fundamental insights into general mechanisms of molecular virology and cell biology.