Functional interaction of MutY homolog with proliferating cell nuclear antigen in fission yeast, Schizosaccharomyces pombe
Functional interaction of MutY homolog with proliferating cell nuclear antigen in fission yeast, Schizosaccharomyces pombe
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DOI：
10.1074/jbc.m111739200
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发表时间：
2002-04-05
影响因子：
4.8
通讯作者：
Lu, AL
中科院分区：
文献类型：
--
作者：
Chang, DY;Lu, AL
MutY同源物（MYH）负责去除含有G或7,8-二氢-8-氧鸟嘌呤（8-oxoG）的模板DNA链上错误结合的腺嘌呤，从而防止G:C到T: a突变。人MYH已被证明与人增殖细胞核抗原（hPCNA）物理相互作用。在这里，我们报道了SpMYH和SpPCNA之间的类似相互作用发生在分裂酵母裂糖酵母pombe中。当SpMYH的PCNA结合基序中的苯丙氨酸444被丙氨酸取代时，SpMYH与SpPCNA的结合未被观察到。酵母细胞中表达的SpMYH F444A突变体具有正常的腺嘌呤糖基化酶和DNA结合活性。然而，在SpMYHDelta细胞中表达这种突变形式的SpMYH不能将细胞的突变频率降低到正常水平。此外，SpMYH与hPCNA相互作用，SpPCNA与hMYH相互作用，但不与含有PCNA结合基序突变的F518A/ F519A突变体hMYH相互作用。虽然表达hMYH的SpMYHDelta细胞部分降低了突变频率，但F518A/F519A突变体hMYH不能降低SpMYHDelta细胞的突变频率。因此，SpMYH和SpPCNA之间的相互作用对于SpMYH避免突变的生物学功能是重要的。
The MutY homolog (MYH) is responsible for removing adenines misincorporated on a template DNA strand containing G or 7,8-dihydro-8-oxoguanine (8-oxoG) and thus preventing G:C to T:A mutations. Human MYH has been shown to interact physically with human proliferating cell nuclear antigen (hPCNA). Here, we report that a similar interaction between SpMYH and SpPCNA occurs in the fission yeast Schizosaccharomyces pombe. Binding of SpMYH to SpPCNA was not observed when phenylalanine 444 in the PCNA binding motif of SpMYH was replaced with alanine. The F444A mutant of SpMYH expressed in yeast cells had normal adenine glycosylase and DNA binding activities. However, expression of this mutant form of SpMYH in a SpMYHDelta cell could not reduce the mutation frequency of the cell to the normal level. Moreover, SpMYH interacted with hPCNA and SpPCNA interacted with hMYH but not with F518A/ F519A mutant hMYH containing mutations in its PCNA binding motif. Although the SpMYHDelta cells expressing hMYH had partially reduced mutation frequency, the F518A/F519A mutant hMYH could not reduce the mutation frequency of SpMYHDelta cells. Thus, the interaction between SpMYH and SpPCNA is important for SpMYH biological function in mutation avoidance.