Aurora A Phosphorylation of YY1 during Mitosis Inactivates its DNA Binding Activity

Abstract

Successful execution of mitotic cell division requires the tight synchronisation of numerous biochemical pathways. The underlying mechanisms that govern chromosome segregation have been thoroughly investigated. However, the mechanisms that regulate transcription factors in coordination with mitotic progression remain poorly understood. In this report, we identify the transcription factor YY1 as a novel mitotic substrate for the Aurora A kinase, a key regulator of critical mitotic events, like centrosome maturation and spindle formation. Using in vitro kinase assays, we show that Aurora A directly phosphorylates YY1 at serine 365 in the DNA-binding domain. Using a new phospho-specific antibody, we show that YY1 phosphorylation at serine 365 occurs during mitosis, and that this phosphorylation is significantly reduced upon inhibition of Aurora A. Furthermore, we show, using electrophoretic mobility shift and chromatin immunoprecipitation assays, that phosphorylation of YY1 at this site abolishes its DNA binding activity in vitro and in vivo. In conformity with this loss of binding activity, phosphorylated YY1 also loses its transctivation ability as demonstrated by a luciferase reporter assay. These results uncover a novel mechanism that implicates Aurora A in the mitotic inactivation of transcription factors.

YY 1 regulates skeletal muscle regeneration through controlling metabolic reprogramming of satellite cells

“…In line with this, Ehz2 loss in mouse was shown to cause a defect in SC proliferation and muscle regeneration (Juan et al , ), phenocopying YY1 iKO . Moreover, in order to substantiate that YY1 represses mitochondrial genes through its direct DNA‐binding activity, re‐expression of a wild‐type (WT) YY1 restored the elevated mitochondrial genes in iKO SCs, but a mutant YY1 (S365D) lacking DNA‐binding activity failed to do so (Alexander & Rizkallah, ); similarly, a second mutant, YY1 (1–394), lacking DNA‐binding domain also did not restore the mitochondrial expression in iKO SCs (Figs S and EV4L). Lastly, as YY1/PRC2 was previously reported to repress Pax7 expression, upon p38 activation (Palacios et al , ), we tested whether Pax7 expression is increased by YY1 loss and surprisingly found Pax7 was decreased in iKO vs. Ctrl SCs (Fig EV4M); this is probably because the YY1/PRC2 repression on Pax7 occurs upon myoblast fusion to myotube but not in actively proliferating myoblast cells (Palacios et al , ).…”

YY1 cistrome analysis uncovers an essential requirement of the YY1:BRD4-PFKP regulatory axis for promoting tumorigenesis of castration-resistant prostate cancer

“…Meanwhile, rescue of YY1 loss by an exogenous YY1 WT restored the PFKP protein level in these cells (Fig. 5d, middle vs left lanes), an effect not seen with YY1 S365D , a DNA-binding-defective mutant 19 (Fig. 5d, right lanes).…”

A flexible microfluidic system for single-cell transcriptome profiling elucidates phased transcriptional regulators of cell cycle

“…Indeed, only 9/78 were determined as phase-specific genes in previous studies 9, 24 , thus demonstrating the merit of our alternative analysis strategy. Differentially active regulators in the absence of phased gene expression changes included YY1 which is subject to regulatory phosphorylation by various cell cycle associated kinases including Aurora A 38 and PLK1 39 , FOXM1 that is regulated by SUMOylation 40 and PLK1 phosphorylation 19 , and REST which is regulated by phosphorylation and USP15 limited polyubiquitination 41 . However, certain transcription factors such as PITX1, SATB2, NR2F2, FOXO3 and MYBL1/B-MYB were regulated at the level of gene expression, likely due to coordinated upstream activity of other master regulators in the cell cycle regulatory gene network.…”