Transcriptional coactivator PC4,a chromatin-associated protein,induces chromatin condensation

Chandrima Das, Kohji Hizume, Kiran Batta, B.R.Prashanth Kumar et al.

PC4, a transcriptional coactivator plays an important role in transcription, replication and repair. This article reports that PC4 is an important component of chromatin inducing condensation gradually.

PC4 is broadly distributed on mitotic chromosomes arm except in centromere. It’s highly associated with chromatin. AFM, CDS and Mnase studies proved that PC4 interacts with core histones H3 and H2B, this interaction is essential for PC4 mediated chromatin condensation. Further experiments shows that PC4 compacts chromatin distinctly compared to linker histone H1.

Silencing of PC4 expression in HeLa cells results in chromatin decompaction and knocking of PC4 up-regulates several genes, leading to arrest of cell cycle.

PC4 is also a unique activator of p53 function. All these shows that PC4 belongs to a protein family which are associated in chromatin condensation.

Mercy G.