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目的研究人巨细胞病毒(HCMV)临床感染株的UL133基因序列特征。方法采集HCMV-DNA阳性者的临床标本,PCR扩增UL133基因全序列,阳性扩增产物克隆到pEASYTM载体后进行序列测定,结合来自于NCBI数据库的15条序列进行UL133基因多态性分析。结果获得20例HCMV感染者的UL133全长序列。多态性分析显示HCMV临床株UL133基因核苷酸变异率为0~9.7%,氨基酸变异率为0~40.2%;不同感染者UL133序列5’端的第32-45位发生了相对集中的非同义突变,其他部分序列较少出现氨基酸缺失及错义突变。其中1例临床感染者UL133序列在163-166位核苷酸出现移码突变。综合NCBI数据库的15株序列分析显示,UL133序列分为G1、G2、G3、G4、G5、G6等6个型,但未发现基因型与HCMV感染的临床表现具有显著关联性。编码蛋白翻译后修饰位点包括酪蛋白激酶磷酸化位点(CKP),蛋白激酶C位点(PKC)以及NLS_BP核定位信号(NLS_BP)。与Toledo株相比,有1株发生移码突变,其他临床株UL133基因编码产物翻译后修饰位点相对保守。结论 HCMV UL133基因核苷酸序列及其编码的氨基酸序列高度保守,但仍具有一定的多态性。这种多态性与HCMV感染临床症状的关系尚待进一步研究。
Objective To study the sequence of UL133 gene in clinical isolates of human cytomegalovirus (HCMV). Methods The clinical samples of HCMV-DNA positive individuals were collected. The full-length sequence of UL133 gene was amplified by PCR. The positive amplification products were cloned into pEASYTM vector and sequenced. Fifteen sequences from NCBI database were used to analyze the UL133 gene polymorphism. Results The full length sequence of UL133 from 20 HCMV infected patients was obtained. Polymorphism analysis showed that the nucleotide variation rate of UL133 gene in HCMV clinical isolates ranged from 0 to 9.7% and the amino acid mutation rate ranged from 0 to 40.2%. The relative concentration of non-homology between the 32nd and 45th positions of the 5 ’ Sense mutations, other parts of the sequence less amino acid deletions and missense mutations. One case of clinical infection UL133 sequence in the 163-166 nucleotide appear frameshift mutations. The 15 NCBI database showed that the UL133 sequences were divided into G1, G2, G3, G4, G5 and G6, but no significant association was found between the genotypes and the clinical manifestations of HCMV infection. The coding protein post-translational modification sites include the casein kinase phosphorylation site (CKP), the protein kinase C site (PKC), and the NLS_BP nuclear localization signal (NLS_BP). Compared with the Toledo strain, one had a frameshift mutation, while the other clinical strains had a relatively conservative post-translational modification of the coding product of the UL133 gene. Conclusion The nucleotide sequence of HCMV UL133 gene and its encoded amino acid sequence are highly conserved but still have some polymorphisms. The relationship between this polymorphism and clinical symptoms of HCMV infection remains to be further studied.