The function of RPAP1 (RNA polymerase II associated protein 1, Ensembl gene identifier ENSG00000103932) is as follows. Forms an interface between the RNA polymerase II enzyme and chaperone/scaffolding protein, suggesting that it is required to connect RNA polymerase II to regulators of protein complex formation. Required for interaction of the RNA polymerase II complex with acetylated histone H3. .