Expression Levels of Glycoprotein O (gO) Vary between Strains of Human Cytomegalovirus, Influencing the Assembly of gH/gL Complexes and Virion Infectivity.
Expression Levels of Glycoprotein O (gO) Vary between Strains of Human Cytomegalovirus, Influencing the Assembly of gH/gL Complexes and Virion Infectivity.
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糖蛋白 O (gO) 的表达水平在人巨细胞病毒株之间存在差异，影响 gH/gL 复合物的组装和病毒粒子的感染性。
DOI：
10.1128/jvi.00606-18
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发表时间：
2018
影响因子：
5.4
通讯作者：
Ryckman,BrentJ
中科院分区：
文献类型：
--
作者：
Zhang,Le;Zhou,Momei;Stanton,Richard;Kamil,Jeremy;Ryckman,BrentJ
人巨细胞病毒的嗜性受包膜糖蛋白复合体Gh/Gl/Go和Gh/Gl/UL128-131的影响。在病毒粒子组装过程中，GO和UL128-131蛋白竞争结合内质网中的Gh/g1。这种组装过程在不同菌株之间明显不同，因为Merlin(ME)病毒粒子含有丰富的Gh/gl/UL128-131和少量的Gh/gl/go，而tr含有更高水平的总Gh/gl，主要以Gh/gl/go的形式存在，但Gh/gl/UL128-131水平比ME低得多。剩下的问题包括(I)这些组装差异背后的机制是什么，以及(Ii)差异是否反映在体外培养适应或自然遗传变异中？由于UL74(GO)开放阅读框(ORF)在氨基酸组成上存在差异，因此我们分析了UL74(GO)开放阅读框(ORF)互换的重组病毒。Tr病毒粒子的传染性是我的40倍。尽管Gh/Gl/Go的水平仍然很低，但UL128-131的转录抑制增强了ME对TR水平的感染力。交换UL74(GO)ORF对TR或ME均无影响。定量免疫沉淀法显示，Gh/gl在TR和ME之间的表达水平在4倍以内，但ME的Go表达水平低20倍，这表明在mRNA转录、翻译或ER相关的快速降解gO方面存在差异。ME复制过程中Go表达的反式互补使感染性增加6倍，而不是UL128-131单独抑制的40倍。总体而言，Gh/gl复合体组装的毒株差异是由于GO和UL128-131表达的差异造成的，而且在成纤维细胞培养过程中UL128-131表达降低的选择性优势远远强于GO高表达的选择性。重要的是，独立分离的HCMV毒株之间的特定遗传差异可能是对临床标本中存在的不同基因型别的纯净选择或随机抽样造成的。结果表明，尽管UL128-131表达降低可能在人巨细胞病毒在成纤维细胞培养中的无细胞增殖过程中赋予强大的选择优势，但增加GO表达的选择压力要弱得多。因此，独立菌株之间GO表达的差异可能代表了体内存在的自然基因变异。这可能对病毒-宿主的相互作用有重要的影响，如免疫识别，并强调了利用多个HCMV毒株研究复制的分子机制的价值。
The tropism of human cytomegalovirus (HCMV) is influenced by the envelope glycoprotein complexes gH/gL/gO and gH/gL/UL128-131. During virion assembly, gO and the UL128-131 proteins compete for binding to gH/gL in the endoplasmic reticulum (ER). This assembly process clearly differs among strains, since Merlin (ME) virions contain abundant gH/gL/UL128-131 and little gH/gL/gO, whereas TR contains much higher levels of total gH/gL, mostly in the form of gH/gL/gO, but much lower levels of gH/gL/UL128-131 than ME. Remaining questions include (i) what are the mechanisms behind these assembly differences, and (ii) do differences reflectin vitroculture adaptations or natural genetic variations? Since the UL74(gO) open reading frame (ORF) differs in 25% of amino acids between TR and ME, we analyzed recombinant viruses in which the UL74(gO) ORF was swapped. TR virions were >40-fold more infectious than ME. Transcriptional repression of UL128-131 enhanced the infectivity of ME to the level of TR, despite still far lower levels of gH/gL/gO. Swapping the UL74(gO) ORF had no effect on either TR or ME. A quantitative immunoprecipitation approach revealed that gH/gL expression levels were within 4-fold between TR and ME, but the gO expression level was 20-fold lower for ME, which suggested differences in mRNA transcription, translation, or rapid ER-associated degradation of gO.trans-Complementation of gO expression during ME replication gave a 6-fold enhancement of infectivity beyond the 40-fold effect of UL128-131 repression alone. Overall, strain variations in the assembly of gH/gL complexes result from differences in the expression of gO and UL128-131, and selective advantages for reduced UL128-131 expression during fibroblast propagation are much stronger than those for higher gO expression.IMPORTANCESpecific genetic differences between independently isolated HCMV strains may result from purifying selection onde novomutations arising during propagation in culture or random sampling among the diversity of genotypes present in clinical specimens. Results presented indicate that while reduced UL128-131 expression may confer a powerful selective advantage during cell-free propagation of HCMV in fibroblast cultures, selective pressures for increased gO expression are much weaker. Thus, variation in gO expression among independent strains may represent natural genotype variability presentin vivo. This may have important implications for virus-host interactions, such as immune recognition, and underscores the value of studying molecular mechanisms of replication using multiple HCMV strains.
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影响因子：
5.4
作者：
Paul T. Wille;A. J. Knoche;J. Nelson;M. Jarvis;David C. Johnson
通讯作者：
Paul T. Wille;A. J. Knoche;J. Nelson;M. Jarvis;David C. Johnson
影响因子：
5.4
作者：
Ryckman, BJ;Jarvis, MA;Johnson, DC
通讯作者：
Johnson, DC
DOI：
10.1073/pnas.0509201102
发表时间：
2005-12-13
影响因子：
11.1
作者：
Wang, D;Shenk, T
通讯作者：
Shenk, T
DOI：
10.1099/vir.0.018994-0
发表时间：
2010-06
期刊：
The Journal of general virology
影响因子：
--
作者：
Dargan DJ;Douglas E;Cunningham C;Jamieson F;Stanton RJ;Baluchova K;McSharry BP;Tomasec P;Emery VC;Percivalle E;Sarasini A;Gerna G;Wilkinson GW;Davison AJ
通讯作者：
Davison AJ
影响因子：
5.4
作者：
CHEE, M;RUDOLPH, SA;JAHN, G
通讯作者：
JAHN, G