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) (By similarity). Highest levels in heart, liver and kidney. Lower levels in brain and lung.