Brickner Jason H
Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, IL, USA.
Curr Opin Cell Biol. 2009 Feb;21(1):127-33. doi: 10.1016/j.ceb.2009.01.007. Epub 2009 Jan 30.
A number of inducible yeast genes are targeted to the nuclear periphery upon transcriptional activation. However, when repressed again, the INO1 and GAL1 genes remain at the nuclear periphery for multiple generations. Retention at the nuclear periphery represents a novel type of transcriptional memory; the peripherally localized, recently repressed state of GAL1 is activated more rapidly than the nucleoplasmically localized long-term repressed state of GAL1. This rapid reactivation involves localization at the nuclear periphery, the SWI/SNF chromatin remodeling complex, the histone variant H2A.Z and the Gal1 protein itself. Here, I review what we have learned about this type of transcriptional memory in yeast, what remains to be resolved and the challenges associated with understanding such epigenetic phenomena.
许多可诱导的酵母基因在转录激活后会定位于核周。然而，当再次受到抑制时，INO1和GAL1基因会在核周保留多代。保留在核周代表了一种新型的转录记忆；与GAL1在核质中处于长期抑制状态相比，GAL1在核周的近期抑制状态被激活得更快。这种快速重新激活涉及核周定位、SWI/SNF染色质重塑复合体、组蛋白变体H2A.Z以及Gal1蛋白本身。在此，我综述了我们对酵母中这种转录记忆类型的了解、有待解决的问题以及理解此类表观遗传现象所面临的挑战。
