MED27

The activation of gene transcription is a multistep process that is triggered by factors that recognize transcriptional enhancer sites in DNA. These factors work with co-activators to direct transcriptional initiation by the RNA polymerase II apparatus. The protein encoded by this gene is a subunit of the CRSP (cofactor required for SP1 activation) complex, which, along with TFIID, is required for efficient activation by SP1. This protein is also a component of other multisubunit complexes e.g. thyroid hormone receptor-(TR-) associated proteins which interact with TR and facilitate TR function on DNA templates in conjunction with initiation factors and cofactors. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene, and a pseudogene of this gene is located on the long arm of chromosome 5.

Full Name

MED27

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.

Biological Process

Positive regulation of transcription elongation from RNA polymerase II promoter Source: ComplexPortal
Positive regulation of transcription initiation from RNA polymerase II promoter Source: ComplexPortal
Regulation of transcription by RNA polymerase II Source: MGI
RNA polymerase II preinitiation complex assembly Source: ComplexPortal
Stem cell population maintenance Source: Ensembl
Transcription initiation from RNA polymerase II promoter Source: ProtInc

Cellular Location

Nucleus

Involvement in disease

Neurodevelopmental disorder with spasticity, cataracts, and cerebellar hypoplasia (NEDSCAC):
An autosomal recessive disorder characterized by global developmental delay, impaired intellectual development, and poor or absent speech. More severely affected individuals do not achieve independent ambulation, whereas others develop some speech and can walk, or show regression later in childhood. Additional features include axial hypotonia, peripheral spasticity, dystonia, cataracts, and seizures. Brain imaging usually shows cerebellar hypoplasia, thin corpus callosum, cerebral atrophy, and hypomyelination.