title: Human MCRS2, a cell-cycle-dependent protein, associates with LPTS/PinX1 and reduces the telomere length.
abstract: Human LPTS/PinX1 is a telomerase-inhibitory protein, which binds to the telomere protein Pin2/TRF1 and the catalytic subunit hTERT of telomerase. To explore the proteins that might be involved in the telomerase pathway, we performed a yeast two-hybrid screening with LPTS/PinX1 as the bait. A novel gene, MCRS2, encoding for an isoform of MCRS1/p78 and MSP58 was isolated. The expression of MCRS2 protein is cell-cycle dependent, accumulating in the very early S phase. MCRS2 interacts with LPTS/PinX1 in vitro, in vivo and colocalizes with LPTS/PinX1 in cells. MCRS2 and its amino terminus inhibit telomerase activity in vitro and long-term overexpression of MCRS2 in SMMC-7721 cells results in a gradual and progressive shortening of telomeres. Our findings suggest that MCRS2 might be a linker between telomere maintenance and cell-cycle regulation.
authors.affiliation: State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China.
authors.forename: Hai
authors.initials: H
authors.lastname: Song
authors.forename: Yiliang
authors.initials: Y
authors.lastname: Li
authors.forename: Guoyuan
authors.initials: G
authors.lastname: Chen
authors.forename: Zhen
authors.initials: Z
authors.lastname: Xing
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.forename: Kazunari K
authors.initials: KK
authors.lastname: Yokoyama
authors.forename: Tsaiping
authors.initials: T
authors.lastname: Li
authors.forename: Mujun
authors.initials: M
authors.lastname: Zhao
mesh_terms: D001483:Base Sequence; D001921:Brain / Q000378:metabolism; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism*; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D006801:Humans; D008099:Liver / Q000378:metabolism; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D011506:Proteins / Q000235:genetics* / Q000378:metabolism*; D016601:RNA-Binding Proteins; D016615:Telomere / Q000235:genetics* / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000235:genetics* / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; C113292:MCRS1 protein, human; D009687:Nuclear Proteins; C440808:PINX1 protein, human; D011506:Proteins; D016601:RNA-Binding Proteins; D025521:Tumor Suppressor Proteins