The majority of duck hepatitis B virus reverse transcriptase in cells is nonencapsidated and is bound to a cytoplasmic structure
The majority of duck hepatitis B virus reverse transcriptase in cells is nonencapsidated and is bound to a cytoplasmic structure
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DOI：
10.1128/jvi.74.18.8648-8657.2000
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发表时间：
2000-09-01
影响因子：
5.4
通讯作者：
Tavis, JE
中科院分区：
文献类型：
--
作者：
Yao, EM;Gong, YH;Tavis, JE
肝病毒逆转录酶与病毒基因组前RNA共译结合。这种核糖核蛋白复合物随后被封装到新生的病毒核心颗粒中，在那里逆转录酶将病毒RNA复制成DNA。在这里，我们报告了75%的鸭乙肝病毒逆转录酶存在于转染的LMH细胞中，不遵循这一众所周知的途径，而是存在于与核心蛋白或核衣壳分离的细胞中。在感染的鸭肝中也有大量的非囊化逆转录酶。非腺苷化逆转录酶以一组复杂的异构体的形式存在，这些异构体很可能是由翻译后修饰产生的。有趣的是，这些同工异构体中只有最小的被封装到病毒护理颗粒中。非腺苷化的逆转录酶在洗涤剂敏感复合物中与一个大的细胞质结构结合。逆转录酶的细胞分布仅部分与核心蛋白重叠，并且这种分布不受阻断衣壳化的影响。这些观察结果提出了逆转录酶的代谢命运可能受到转录后调控的可能性，并且逆转录酶可能在病毒复制周期中发挥作用，而不仅仅是在复制病毒基因组中发挥众所周知的功能。
The hepadnavirus reverse transcriptase binds cotranslationally to the viral pregenomic RNA. This ribonucleoprotein complex is then encapsidated into nascent viral core particles, where the reverse transcriptase copies the viral RNA into DNA. Here we report that 75% of the duck hepatitis B virus reverse transcriptase present in transfected LMH cells does not follow this well-known pathway but rather exists in the cell separate from the core protein or nucleocapsids. The nonencapsidated reverse transcriptase is also abundant in infected duck liver. The nonencapsidated reverse transcriptase exists as a complex set of isoforms that are mast likely produced by posttranslational modification. Interestingly, only the smallest of these isoforms is encapsidated into viral care particles. The nonencapsidated reverse transcriptase is bound to a large cellular cytoplasmic structure(s) in a detergent-sensitive complex. The cellular distribution of the reverse transcriptase only partially overlaps that of the core protein, and this distribution is unaffected by blocking encapsidation. These observations raise the possibilities that the metabolic fate of the reverse transcriptase may be posttranscriptionally regulated and that the reverse transcriptase may have roles in the viral replication cycle beyond its well-known function in copying the viral genome.