Component of a THAP1/THAP3-HCFC1-OGT complex that is required for the regulation of the transcriptional activity of RRM1. Component of a THAP1/THAP3-HCFC1-OGT complex that contains at least, either THAP1 or THAP3, HCFC1 and OGT. Interacts directly with OGT and HCFC1 (via its HBM). Highly expressed in heart, skeletal muscle and placenta. Weaker expression in brain, kidney and liver.