Evolution of Sindbis virus with a low-methionine-resistant phenotype is dependent both on a pre-existing mutation and on the methionine concentration in the medium.
Evolution of Sindbis virus with a low-methionine-resistant phenotype is dependent both on a pre-existing mutation and on the methionine concentration in the medium.
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DOI：
10.1371/journal.pone.0060504
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Li ML
中科院分区：
文献类型：
--
作者：
Stollar V;Mensah V;Adams S;Li ML
SVlm21 是辛德毕斯病毒的突变体，通过在低蛋氨酸培养基中维持的蚊子细胞中连续传代病毒而分离；因此它具有低甲硫氨酸抗性（LMR）表型。该表型需要在 nts 319 和 321 处发生突变；这些突变导致病毒甲基转移酶 nsP1 中的第 87 和 88 位分别由 Arg 变为 Leu，Ser 变为 Cys。为了更好地了解 SVlm21 的起源，我们对仅具有这些氨基酸变化之一的病毒进行了连续传代，但在维持在正常蛋氨酸培养基中的蚊子细胞中。无论传代是从SV319还是从SV321开始，出现的优势病毒群体总是获得第二个SVlm21氨基酸变化。然而，当用既不具有nt 319也不具有nt321突变的病毒开始传代时，即使经过许多次传代，在传代的病毒群体中也没有看到这些突变。当病毒编码野生型 RDRP（第 4 代）而不是 SVpzf 编码的突变型 RDRP（第 7 代）时，具有 LMR 表型的病毒出现得更早。当蚊子细胞培养基中的蛋氨酸浓度增加至250 µM时，需要传代20次以上，直到LMR表型占主导地位。进行竞争实验以比较SVlm21、SVwt、SV319和SV321彼此的相对适合度。我们的结果表明 SVlm21 对 SVwt 以及 SV319 和 SV321 均占主导地位。然而，SV319和SV321能够与SVwt共存，这意味着在这些混合感染中SVwt的存在抑制了SVlm21的出现。最后，我们的实验强调了病毒群体如何通过突变和选择来适应简单代谢物 S-腺苷甲硫氨酸的细胞内浓度。
SVlm21 is a mutant of Sindbis virus which was isolated by serial passage of virus in mosquito cells maintained in low-methionine medium; it therefore has a low-methionine-resistant (LMR) phenotype. This phenotype requires mutations at nts 319 and 321; these mutations result in Arg to Leu and Ser to Cys changes at positions 87 and 88 respectively in the viral methyl transferase, nsP1. To better understand the genesis of SVlm21, we carried out serial passages of viruses having only one of these amino acid changes, but in mosquito cells maintained in normal methionine-medium. Whether the passage was begun with SV319 or with SV321, the dominant virus population which emerged always acquired the second SVlm21 amino acid change. However, when the passage was begun with virus having neither the nt 319 or the nt321 mutation, even after many passages neither of these mutations was seen in the passaged virus population. Virus with the LMR phenotype emerged earlier when the virus encoded a wild-type RDRP (passage 4) rather than the mutant RDRP encoded by SVpzf (passage 7). When the methionine concentration in the medium of mosquito cells was increased to 250 µM, more than 20 passages were required until the LMR phenotype predominated. Competition experiments were carried out to compare the relative fitness of SVlm21, SVwt, SV319 and SV321 to each other. Our results indicated that SVlm21 was dominant to SVwt, as well as to both SV319 and SV321. However, SV319 and SV321 were able to co-exist with SVwt implying that in these mixed infection the presence of SVwt inhibited the emergence of SVlm21. Finally, our experiments highlight how a virus population by mutation and selection can adapt to the intracellular concentration of a simple metabolite, S-adenosylmethionine.
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DOI：
10.1073/pnas.1111650108
发表时间：
2011-09-20
影响因子：
11.1
作者：
Coffey, Lark L.;Beeharry, Yasnee;Vignuzzi, Marco
通讯作者：
Vignuzzi, Marco
DOI：
10.1073/pnas.1232294100
发表时间：
2003-06-10
影响因子：
11.1
作者：
Pfeiffer, JK;Kirkegaard, K
通讯作者：
Kirkegaard, K
影响因子：
5.4
作者：
Bick, MJ;Carroll, JWN;MacDonald, MR
通讯作者：
MacDonald, MR
影响因子：
3.7
作者：
Lin, YH;Yadav, P;Stollar, V
通讯作者：
Stollar, V
影响因子：
3.7
作者：
SARVER, N;STOLLAR, V
通讯作者：
STOLLAR, V