tailieunhanh - Báo cáo khoa học: Analysis of the contribution of changes in mRNA stability to the changes in steady-state levels of cyclin mRNA in the mammalian cell cycle

Cyclins are the essential regulatory subunits of cyclin-dependent protein kinases. They accumulate and disappear periodically at specific phases of the cell cycle. Here we investigated whether variations in cyclin mRNA levels in exponentially growing cells can be attributed to changes in mRNA stability. Mouse EL4 lymphoma cells and 3T3 fibroblasts were synchron-ized by elutriation or cell sorting. | ềFEBS Journal Analysis of the contribution of changes in mRNA stability to the changes in steady-state levels of cyclin mRNA in the mammalian cell cycle Anna Penelova1 Larry Richman1 Barbara Neupert1 Viesturs Simanis2 and Lukas C. Kuhn1 1 Genetics Unit Swiss Institute for ExperimentalCancer Research ISREC Epalinges Switzerland 2 CellCycle ControlLaboratory Swiss Institute for ExperimentalCancer Research ISREC Epalinges Switzerland Keywords cell cycle cyclin elutriation fluorescence activated cell sorter mRNA stability Correspondence L. C. Kuhn Swiss Institute for Experimental Cancer Research Genetics Unit Chemin des Boveresses 155 CH-1066 Epalinges Switzerland Fax 4121 652 69 33 Tel 4121 692 58 36 E-mail Received 29 June 2005 accepted 16 August 2005 doi Cyclins are the essential regulatory subunits of cyclin-dependent protein kinases. They accumulate and disappear periodically at specific phases of the cell cycle. Here we investigated whether variations in cyclin mRNA levels in exponentially growing cells can be attributed to changes in mRNA stability. Mouse EL4 lymphoma cells and 3T3 fibroblasts were synchronized by elutriation or cell sorting. Steady-state levels and degradation of cyclin mRNAs and some other cell cycle related mRNAs were measured at early G1 late G1 S and G2 M phases. In both cell lines mRNAs of cyclins C D1 and D3 remained unchanged throughout the cell cycle. In contrast cyclin A2 and B1 mRNAs accumulated and between early G1 and G2 M phase whereas cyclin E1 mRNA decreased . Mouse cyclin A2 and B1 genes by alternative polyadenylation gave rise to more than one transcript. In both cases the longer transcripts were the minor species but accumulated more strongly in G2 M phase. All mRNAs were rather stable with half-lives of h for cyclin E1 mRNA and 3-4 h for the others. Changes in mRNA stability accounted for the accumulation in G2 M phase of the short cyclin A2 and