MED4 (mediator complex subunit 4), also known as ARC36, DRIP36 or VDRIP, is a 270 amino acid protein that localizes to the nucleus and exists as a component of the mediator complex. Working in tandem with several other proteins, including Med8 and MED25, MED4 serves as a scaffold for the assembly of a functional preinitiation complex with Pol II and general transcription factors, thereby activating the transcription of Pol II-dependent genes.
