getting a transcription factor to only one nucleus following mitosis得到一个转录因子后只有一个核有丝分裂.pdfVIP

Primer Getting a Transcription Factor to Only One Nucleus Following Mitosis Emily J. Parnell, David J. Stillman* he growth and development of all eukaryotes depends only in mother cells. Both Ace2 and Swi5 are regulated by on the process of asymmetric cell division, in which a a series of cell cycle events that culminates in expression of Tsingle cell gives rise to two genetically identical cells their target genes in late M phase, before mitotic division, that adopt distinct fates [1,2]. Asymmetry occurs when two and early G1, the first gap when the cell produces proteins cells are exposed to different environmental stimuli or when and grows in preparation for division. The ACE2 and SWI5 specific mRNAs or proteins (known as cell fate determinants) genes are transcribed in G2, the second gap, following are segregated unequally. In recent years, studies in a variety genome replication (S phase), and the proteins remain in of organisms have furthered our understanding of how the cytoplasm until the end of mitosis, when they translocate these factors can cause two cells from the same division to and accumulate in the nucleus and activate expression of experience different transcriptional outcomes, and thus take target genes. The specific timing of nuclear translocation different paths. appears to be achieved by a regulated nuclear localization One model system for the study of asymmetric gene signal (NLS) present in a region highly conserved between expression is the budding yeast Saccharomyces cerevisiae. the two proteins. Phosphorylation of specific residues in the Asymmetry in S. cerevisiae is defined as the di