a retinoblastoma orthologue is a major regulator of s-phase, mitotic, and developmental gene expression in dictyostelium视网膜母细胞瘤orthologue s阶段的主要监管机构,有丝分裂,并在盘基网柄菌发育的基因表达.pdfVIP

A Retinoblastoma Orthologue Is a Major Regulator of S- Phase, Mitotic, and Developmental Gene Expression in Dictyostelium 1 2,3 4 5 6{ Kimchi Strasser *, Gareth Bloomfield , Asa MacWilliams , Adriano Ceccarelli , Harry MacWilliams , Adrian Tsang1 1 Biology Department and Centre for Structural and Functional Genomics, Concordia University, Montreal, Canada, 2 MRC Laboratory of Molecular Biology, Cambridge, United Kingdom, 3 Wellcome Trust Sanger Institute, Hinxton, United Kingdom, 4 Siemens Corporate Technology, Munich, Germany, 5 Neuroscience Institute Cavalieri ¨ Ottolenghi, University of Torino, Torino, Italy, 6 Biozentrum der Ludwig-Maximilans-Universitat, Munich, Germany Abstract Background: The retinoblastoma tumour suppressor, Rb, has two major functions. First, it represses genes whose products are required for S-phase entry and progression thus stabilizing cells in G1. Second, Rb interacts with factors that induce cell- cycle exit and terminal differentiation. Dictyostelium lacks a G1 phase in its cell cycle but it has a retinoblastoma orthologue, rblA. Methodology/Principal Findings: Using microarray analysis and mRNA-Seq transcriptional profiling, we show that RblA strongly represses genes whose products are involved in S phase and mitosis. Both S-phase and mitotic genes are upregulated at a single point in late G2 and again in mid-development, near the time when cell cycling is reactivated. RblA also activates a set of genes unique to slime moulds that function in terminal differentiation. Conclusions: Like its mammalian cou