MED25

This gene encodes a component of the transcriptional coactivator complex termed the Mediator complex. This complex is required for transcription of most RNA polymerase II-dependent genes. The encoded protein plays a role in chromatin modification and in preinitiation complex assembly. Mutations in this gene are associated with Charcot-Marie-Tooth disease type 2B2.

Full Name

MEDIATOR COMPLEX SUBUNIT 25

Function

Component of the Mediator complex, a coactivator involved in the regulated transcription of nearly all RNA polymerase II-dependent genes. Mediator functions as a bridge to convey information from gene-specific regulatory proteins to the basal RNA polymerase II transcription machinery. Mediator is recruited to promoters by direct interactions with regulatory proteins and serves as a scaffold for the assembly of a functional preinitiation complex with RNA polymerase II and the general transcription factors. Required for RARA/RXRA-mediated transcription.

Biological Process

Negative regulation of fibroblast proliferation Source: UniProtKB
Negative regulation of transcription by RNA polymerase II Source: UniProtKB
Positive regulation of chromatin binding Source: UniProtKB
Positive regulation of mediator complex assembly Source: UniProtKB
Positive regulation of transcription by RNA polymerase II Source: UniProtKB
Positive regulation of transcription elongation from RNA polymerase II promoter Source: ComplexPortal
Positive regulation of transcription initiation from RNA polymerase II promoter Source: ComplexPortal
RNA polymerase II preinitiation complex assembly Source: ComplexPortal

Cellular Location

Nucleus

Involvement in disease

Charcot-Marie-Tooth disease 2B2 (CMT2B2):
A recessive axonal form of Charcot-Marie-Tooth disease, a disorder of the peripheral nervous system, characterized by progressive weakness and atrophy, initially of the peroneal muscles and later of the distal muscles of the arms. Charcot-Marie-Tooth disease is classified in two main groups on the basis of electrophysiologic properties and histopathology: primary peripheral demyelinating neuropathies (designated CMT1 when they are dominantly inherited) and primary peripheral axonal neuropathies (CMT2). Neuropathies of the CMT2 group are characterized by signs of axonal degeneration in the absence of obvious myelin alterations, normal or slightly reduced nerve conduction velocities, and progressive distal muscle weakness and atrophy.
Basel-Vanagaite-Smirin-Yosef syndrome (BVSYS):
An autosomal recessive syndrome characterized by eye, brain, cardiac and palatal abnormalities as well as growth retardation, microcephaly and severe intellectual disability.