TRAP220/MED1 (Mediator complex subunit 1, TRIP2, Thyroid receptor-interacting protein 2) is a component of the Mediator complex, a coactivator involved in the regulated transcription of most genes transcribed by RNA polymerase II. MED1 functions as a bridge to convey information from gene-specific regulatory proteins to the basal RNA polymerase II transcription machinery. MED1 is recruited to promoters by direct interactions with regulatory proteins and serves as a scaffold for the assembly of a functional pre-initiation complex with RNA polymerase II and the general transcription factors.
