Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
Viruses. 2014 Jan 16;6(1):284-300. doi: 10.3390/v6010284.
Retroviruses are a family of viruses that cause a broad range of pathologies in animals and humans, from the apparently harmless, long-term genomic insertion of endogenous retroviruses, to tumors induced by the oncogenic retroviruses and acquired immunodeficiency syndrome (AIDS) resulting from human immunodeficiency virus infection. Disease can be the result of diverse mechanisms, including tumorigenesis induced by viral oncogenes or immune destruction, leading to the gradual loss of CD4 T-cells. Of the virally encoded proteins common to all retroviruses, the envelope (Env) displays perhaps the most diverse functionality. Env is primarily responsible for binding the cellular receptor and for effecting the fusion process, with these functions mediated by protein domains localized to the exterior of the virus. The remaining C-terminal domain may have the most variable functionality of all retroviral proteins. The C-terminal domains from three prototypical retroviruses are discussed, focusing on the different structures and functions, which include fusion activation, tumorigenesis and viral assembly and lifecycle influences. Despite these genetic and functional differences, however, the C-terminal domains of these viruses share a common feature in the modulation of Env ectodomain conformation. Despite their differences, perhaps each system still has information to share with the others.
逆转录病毒是一类病毒，它们在动物和人类中引起广泛的病理变化，从明显无害的、长期的内源性逆转录病毒基因组插入，到致癌逆转录病毒诱导的肿瘤和人类免疫缺陷病毒感染引起的获得性免疫缺陷综合征（艾滋病）。疾病可能是多种机制的结果，包括病毒癌基因诱导的肿瘤发生或免疫破坏，导致 CD4 T 细胞逐渐丧失。在所有逆转录病毒共有的病毒编码蛋白中，包膜（Env）可能显示出最多样化的功能。Env 主要负责结合细胞受体并实现融合过程，这些功能由定位于病毒外部的蛋白结构域介导。剩下的 C 端结构域可能是所有逆转录病毒蛋白中功能最可变的。讨论了三种典型逆转录病毒的 C 端结构域，重点介绍了不同的结构和功能，包括融合激活、肿瘤发生以及病毒组装和生命周期的影响。然而，尽管存在这些遗传和功能差异，这些病毒的 C 端结构域在调节 Env 外显子构象方面具有共同的特征。尽管存在差异，但每个系统可能仍然有信息与其他系统共享。
