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Abstract：
Polyomavirus (PyV) Large T-antigen (LT) is the major viral regulatory protein that targets numerous cellular pathways for cellular transformation and viral replication. LT directly recruits the cellular replication factors involved in initiation of viral DNA replication through mutual interactions between LT, DNA polymerase alpha-primase (Polprim), and single-stranded DNA binding complex, (RPA). Activities and interactions of these complexes are known to be modulated by post-translational modifications; however, high-sensitivity proteomic analyses of the PTMs and proteins associated have been lacking. High-resolution liquid chromatography tandem mass spectrometry (LC-MS/MS) of the immunoprecipitated factors (IPMS) identified 479 novel phosphorylated amino acid residues (PAARs) on the three factors; the function of one has been validated. IPMS revealed 374, 453, and 183 novel proteins associated with the three, respectively. A significant transcription-related process network identified by Gene Ontology (GO) enrichment analysis was unique to LT. Although unidentified by IPMS, the ETS protooncogene 1, transcription factor (ETS1) was significantly overconnected to our dataset indicating its involvement in PyV processes. This result was validated by demonstrating that ETS1 coimmunoprecipitates with LT. Identification of a novel PAAR that regulates PyV replication and LT\'s association with the protooncogenic Ets1 transcription factor demonstrates the value of these results for studies in PyV biology.
摘要：
多瘤病毒（PyV）大T抗原（LT）是主要的病毒调节蛋白，其靶向许多细胞途径进行细胞转化和病毒复制。LT通过LT之间的相互作用直接募集参与病毒DNA复制起始的细胞复制因子，DNA聚合酶α-primase（Polprim），和单链DNA结合复合物，（RPA）。已知这些复合物的活性和相互作用受翻译后修饰的调节；然而，缺乏对PTM和相关蛋白质的高灵敏度蛋白质组学分析。高分辨液相色谱串联质谱(LC-MS/MS)对免疫沉淀因子(IPMS)鉴定出479个新的磷酸化氨基酸残基(PAARs)对这三个因子的作用进行了验证。IPMS揭示了374、453和183种与这三种蛋白质相关的新蛋白质，分别。通过基因本体论（GO）富集分析鉴定的重要转录相关过程网络是LT独有的。虽然未被IPMS识别，ETS原癌基因1,转录因子(ETS1)与我们的数据集显著过度关联,表明其参与PyV过程.通过证明ETS1与LT共免疫沉淀来验证该结果。鉴定出调节PyV复制和LT\与原癌基因Ets1转录因子关联的新型PAAR，证明了这些结果对PyV生物学研究的价值。
