BIOL 483 Lecture Notes - Lecture 62: Chromosome, Hdac3, Ubiquitin
Document Summary
Positive regulation of xist and tsix by ncrnas. > expression boosted by other ncrnas (eg. xist-ar, jpx) > expression boosted by other ncrnas (eg. xite, linx) Region a = for recruitment of spen and hdac3 (involved in x inactivation initiation) Region b & c = for recruitment of prc1 (after initiation, before maintenance) Region f = for recruitment of lbr that brings inactive x to nuclear envelope. Timing of events of transition phase: xist recruits prc1 to ubitinate h2ak119, h2ak119ub recruits prc2 (methylate h3k27me3) and dnmt3a/b (for de novo. Dna methylation: xist coats entire inactive x, inactive x tethered to nuclear periphery. In order for maintenance to happen, macro h2a must be recruited. After maintenance, no longer need to maintain silent state. Xist not needed because inactive x stays silent even if xist removed. Inactive x locates to nuclear periphery (aka lamina/ lamin b) in order to get to final state of barr body.
