Nucleolar Localization of HIV-1 Rev Is Required, Yet Insufficient for Production of Infectious Viral Particles.
Nucleolar Localization of HIV-1 Rev Is Required, Yet Insufficient for Production of Infectious Viral Particles.
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DOI：
10.1089/aid.2017.0306
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发表时间：
2018-11
影响因子：
1.5
通讯作者：
Rossi JJ
中科院分区：
文献类型：
--
作者：
Arizala JAC;Takahashi M;Burnett JC;Ouellet DL;Li H;Rossi JJ
由于耐药性和持续潜伏期，联合抗逆转录病毒治疗未能完全抑制HIV-1。新的治疗干预需要了解负责病毒复制的细胞内途径，特别是那些未被抗逆转录病毒药物靶向的途径。一个研究较少的现象是REV磷蛋白的核仁定位，它通过与内含子顺式作用靶标-REV反应元件(RRE)的多聚体完成未剪接/部分剪接的HIV mRNA的核质转运。REV含有一个核仁定位信号(NOLS)，该信号由富含精氨酸的基序的COOH末端组成，可在核仁内积累，被认为是REV与细胞蛋白相互作用的基础，介导非依赖于mRNA的核输出和剪接。在REV-NOL中缺失和单点突变的情况下，研究了REV-1产生和感染过程中REV核仁通路的功能。根据REV-NOL诱导的突变被假设为使HIV-1感染循环失活。HIV-1HXB2复制停止，REV突变由于丢失或替换多个精氨酸残基而无法进入核仁。然而，缺少单个精氨酸残基的REV突变仍严格保持核仁模式，并参与前病毒的生产，效率降低。在表达核仁定位突变后，病毒RNA包装的效率也降低了。这些结果是在含有病毒主干(M4、M5和M6)核仁定位突变的变异HIV-1NL4-3的传播过程中观察到的。REV单点突变产生的慢病毒颗粒可以在极低的频率下被转导。同样，与WT(野生型)HIV-1NL4-3不同，HIV-1NL4-3 Rev-NOLS变种失去了传染性。HIV-1NL4-3与野生型HIV-1NL4-3一样，具有进入宿主和逆转录的能力，但缺乏完成完整感染周期的能力。我们目前揭示，在REV-NOLS突变存在的情况下，病毒整合被解除调控。
Combination antiretroviral therapy fails in complete suppression of HIV-1 due to drug resistance and persistent latency. Novel therapeutic intervention requires knowledge of intracellular pathways responsible for viral replication, specifically those untargeted by antiretroviral drugs. An understudied phenomenon is the nucleolar localization of Rev phosphoprotein, which completes nucleocytoplasmic transport of unspliced/partially spliced HIV mRNA through multimerization with intronic cis-acting targets—the Rev-response element (RRE). Rev contains a nucleolar localization signal (NoLS) comprising the COOH terminus of the arginine-rich motif for accumulation within nucleoli—speculated as the interaction ground for Rev with cellular proteins mediating mRNA-independent nuclear export and splicing. Functionality of Rev nucleolar access during HIV-1 production and infection was investigated in the context of deletion and single-point mutations within Rev-NoLS. Mutations induced upon Rev-NoLS are hypothesized to inactivate the HIV-1 infectious cycle. HIV-1HXB2 replication ceased with Rev mutations lacking nucleolar access due to loss or replacement of multiple arginine residues. Rev mutations missing single arginine residues remained strictly nucleolar in pattern and participated in proviral production, however, with reduced efficiency. Viral RNA packaging also decreased in efficiency after expression of nucleolar-localizing mutations. These results were observed during propagation of variant HIV-1NL4-3 containing nucleolar-localizing mutations within the viral backbone (M4, M5, and M6). Lentiviral particles produced with Rev single-point mutations were transducible at extremely low frequency. Similarly, HIV-1NL4-3 Rev-NoLS variants lost infectivity, unlike virulent WT (wild type) HIV-1NL4-3. HIV-1NL4-3 variants were capable of CD4+ host entry and reverse transcription as WT HIV-1NL4-3, but lacked ability to complete a full infectious cycle. We currently reveal that viral integration is deregulated in the presence of Rev-NoLS mutations.