Physical and functional interactions between hnRNP K and PRMT family proteins.

The mechanism underlying the protein-protein interaction of hnRNP K and PRMT family proteins is unclear. We examined and confirmed the arginine methylation of hnRNP K protein by PRMT1, not CARM1, via their direct binding. We also studied hnRNP K protein complexes containing CARM1, as well as PRMT1, using co-immunoprecipitation analysis. PRMT family proteins might be involved in the regulation of hnRNP K functions in nuclear receptor coactivator, transactivation, and p21 gene and protein expressions. We believe these observations will help provide insights into the regulation of hnRNP K protein functions via the recruitment of its associated proteins, including its arginine methylation-modifying proteins.