Poster Presentation 16th Asian Conference on Transcription 2019

WDR5 is a novel partner of KLF3 and is important in KLF3 genomic localisation and gene regulation (1173)

Lu YaNG 1 , Tanit Cavalit 1 , Manan Shah 1 , Wooi F Lim 1 , Ling Zhong 1 , Mark J Raftery 1 , Marc R Wilkins 1 , Kate G R Quinlan 1 , Merlin Crossley 1
  1. University of New South Wales, Sydney, NSW, Australia

Transcription factors are generally considered to be comprised of two main components; a DNA-binding domain (DBD) and a functional domain (FD). Unsurprisingly, it is typically thought that the DBD is responsible for localisation and DNA binding whereas the FD is involved in transcriptional regulation. However, we have previously shown that the zinc finger transcription factor Kr├╝ppel like factor 3 (KLF3) does not solely rely on the DBD and that the FD also plays a role in genome-wide localisation. We hypothesised that this may be due to the interaction of the FD with a cofactor(s).

To identify potential candidates, we performed co-immunoprecipitation coupled mass spectrometry (CoIP/MS) using a cell line stably expressing the KLF3 FD. WDR5, a member of the WD repeat protein family was identified as a novel KLF3 partner protein and was investigated further. We mapped the interaction interface between WDR5 and the KLF3 FD, identifying a key residue and generating a KLF3 mutant construct that was unable to bind WDR5. To study the role of this interaction, we generated MEF cell lines overexpressing either WT KLF3 or Mutant KLF3 and performed KLF3 and WDR5 ChIP-seq and RNA-seq.

The mutation which disrupted the KLF3/WDR5 interaction caused genome-wide changes to KLF3 binding as well as significant transcriptome changes suggesting that the interaction is both important for KLF3 genomic localisation and gene regulation. Most genes where KLF3 binding is lost due to the mutation are downregulated, suggesting that the KLF3/WDR5 interaction is particularly important in gene activation.