Influence of PB2 host-range determinants on the intranuclear mobility of the influenza A virus polymerase.
Influence of PB2 host-range determinants on the intranuclear mobility of the influenza A virus polymerase.
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DOI：
10.1099/vir.0.031492-0
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发表时间：
2011-07
期刊：
影响因子：
--
通讯作者：
Digard P
中科院分区：
文献类型：
--
作者：
Foeglein Á;Loucaides EM;Mura M;Wise HM;Barclay WS;Digard P
禽流感A病毒通常不能在哺乳动物细胞中有效繁殖。病毒聚合酶蛋白PB 2对于这种宿主限制是重要的，在残基627和其他位置处的氨基酸多态性充当禽或人适应病毒的“签名”。限制被假设是由于差异的相互作用（无论是积极的或抑制性）与不明细胞因子。我们应用荧光恢复后光漂白（FRAP），以A/PR/8/34和A/土耳其/英格兰/50-92/91为模型菌株，研究细胞核中的病毒聚合酶的流动性。正如预期的那样，聚合酶与禽类PB 2蛋白的转录活性强烈依赖于人而非禽类细胞中残基627的身份，这与失活聚合酶在人而非禽类细胞核中的显著较慢的扩散相关。相比之下，PR 8聚合酶的活性和迁移率受残基627的影响要小得多。序列比较，然后进行诱变分析，确定在已知的主机范围特定的位置271，588和701，以及一个新的决定因素在位置636作为贡献者的PR 8和土耳其PB 2蛋白的主机特异性活性的残基。此外，差的转录活性和缓慢的扩散流动性之间的相关性得以维持。然而，活动并没有强制性地与预测的表面电荷的627域。总的来说，我们的数据支持宿主核因子与病毒聚合酶相互作用并调节其活性的假设。虽然我们无法区分积极和抑制作用，但这些数据对这些因素如何运作具有影响。
Avian influenza A viruses often do not propagate efficiently in mammalian cells. The viral polymerase protein PB2 is important for this host restriction, with amino-acid polymorphisms at residue 627 and other positions acting as ‘signatures’ of avian- or human-adapted viruses. Restriction is hypothesized to result from differential interactions (either positive or inhibitory) with unidentified cellular factors. We applied fluorescence recovery after photobleaching (FRAP) to investigate the mobility of the viral polymerase in the cell nucleus using A/PR/8/34 and A/Turkey/England/50-92/91 as model strains. As expected, transcriptional activity of a polymerase with the avian PB2 protein was strongly dependent on the identity of residue 627 in human but not avian cells, and this correlated with significantly slower diffusion of the inactive polymerase in human but not avian nuclei. In contrast, the activity and mobility of the PR8 polymerase was affected much less by residue 627. Sequence comparison followed by mutagenic analyses identified residues at known host-range-specific positions 271, 588 and 701 as well as a novel determinant at position 636 as contributors to host-specific activity of both PR8 and Turkey PB2 proteins. Furthermore, the correlation between poor transcriptional activity and slow diffusional mobility was maintained. However, activity did not obligatorily correlate with predicted surface charge of the 627 domain. Overall, our data support the hypothesis of a host nuclear factor that interacts with the viral polymerase and modulates its activity. While we cannot distinguish between positive and inhibitory effects, the data have implications for how such factors might operate.
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影响因子：
5.4
作者：
Fodor, E;Smith, M
通讯作者：
Smith, M
影响因子：
64.5
作者：
FIELDS, S;WINTER, G
通讯作者：
WINTER, G
影响因子：
64.8
作者：
ALMOND, JW
通讯作者：
ALMOND, JW
影响因子：
14.9
作者：
Lee, MTM;Bishop, K;Tiley, L
通讯作者：
Tiley, L
DOI：
10.1073/pnas.0507415102
发表时间：
2005-12-20
影响因子：
11.1
作者：
Gabriel, G;Dauber, B;Stech, J
通讯作者：
Stech, J