Escape variants of the XPR1 gammaretrovirus receptor are rare due to reliance on a splice donor site and a short hypervariable loop.
Escape variants of the XPR1 gammaretrovirus receptor are rare due to reliance on a splice donor site and a short hypervariable loop.
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由于依赖剪接供体位点和短的高变环，XPR1 γ逆转录病毒受体的逃逸变体很少见。
DOI：
10.1016/j.virol.2014.07.049
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发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
Kozak,ChristineA
中科院分区：
文献类型：
--
作者：
Lu,Xiaoyu;Martin,Carrie;Bouchard,Christelle;Kozak,ChristineA
异嗜性/多嗜性小鼠白血病病毒（xp - mlv） XPR1受体的进入决定因素位于其第三和第四个假定的细胞外环（ecl）中。关键的ECL3受体决定因子覆盖剪接供体，在脊椎动物XPR1基因中具有进化保守性；3个罕见的替换突变中有2个在这个位点破坏这个受体的决定因素。13个残基ECL4是高可变的，携带完整ECL3位点的替换突变改变但不取消受体活性，包括用水母（刺胞）XPR1替换整个环。由于在所有x - mlv感染的mus亚种中都发现了ECL4缺失，因此我们删除了每个ECL4残基，以确定缺失相关的限制是残基特异性的还是受环大小的影响。所有的缺失都会影响受体功能，尽管不同的缺失会影响不同的xp - mlv。因此，受体使用受约束的剪接位点和耐受突变的环严重限制了宿主逃逸突变的可能性。
Entry determinants in the XPR1 receptor for the xenotropic/polytropic mouse leukemia viruses (XP-MLVs) lie in its third and fourth putative extracellular loops (ECLs). The critical ECL3 receptor determinant overlies a splice donor and is evolutionarily conserved in vertebrate XPR1 genes; 2 of the 3 rare replacement mutations at this site destroy this receptor determinant. The 13 residue ECL4 is hypervariable, and replacement mutations carrying an intact ECL3 site alter but do not abolish receptor activity, including replacement of the entire loop with that of a jellyfish (Cnidaria) XPR1. Because ECL4 deletions are found in all X-MLV-infectedMussubspecies, we deleted each ECL4 residue to determine if deletion-associated restriction is residue-specific or is effected by loop size. All deletions influence receptor function, although different deletions affect different XP-MLVs. Thus, receptor usage of a constrained splice site and a loop that tolerates mutations severely limits the likelihood of host escape mutations.