Endogenous mediator
Encyclopedia
Endogenous mediators are intracellular proteins that enhance and activate the functions of other proteins. This term is commonly used in molecular biology
and cell biology
to describe a specific protein complex that acts in transcription
as a coactivator
. This Mediator complex
is located within the cell nucleus
.
The Mediator complex is required for the successful transcription
of nearly all class II gene
promoters in yeast. It works in the same manner in mammals. The mediator functions as a coactivator and binds to the C-terminal domain of RNA polymerase II
holoenzyme, acting as a bridge between this enzyme and transcription factor
s.
Molecular biology
Molecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry...
and cell biology
Cell biology
Cell biology is a scientific discipline that studies cells – their physiological properties, their structure, the organelles they contain, interactions with their environment, their life cycle, division and death. This is done both on a microscopic and molecular level...
to describe a specific protein complex that acts in transcription
Transcription (genetics)
Transcription is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes...
as a coactivator
Coactivator (genetics)
A coactivator is a protein that increases gene expression by binding to an activator which contains a DNA binding domain. The coactivator is unable to bind DNA by itself....
. This Mediator complex
Mediator (coactivator)
Mediator is a multiprotein complex that functions as a transcriptional coactivator. It was discovered by Roger D. Kornberg, winner of the 2006 Nobel Prize in Chemistry...
is located within the cell nucleus
Cell nucleus
In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...
.
The Mediator complex is required for the successful transcription
Transcription (genetics)
Transcription is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes...
of nearly all class II gene
Class II gene
A class II gene is a type of gene that codes for a protein. Class II genes are transcribed by RNAP II.Class II genes have a promoter that often contains a TATA box.Basal transcription of class II genes requires the formation of a preinitiation complex....
promoters in yeast. It works in the same manner in mammals. The mediator functions as a coactivator and binds to the C-terminal domain of RNA polymerase II
RNA polymerase II
RNA polymerase II is an enzyme found in eukaryotic cells. It catalyzes the transcription of DNA to synthesize precursors of mRNA and most snRNA and microRNA. A 550 kDa complex of 12 subunits, RNAP II is the most studied type of RNA polymerase...
holoenzyme, acting as a bridge between this enzyme and transcription factor
Transcription factor
In molecular biology and genetics, a transcription factor is a protein that binds to specific DNA sequences, thereby controlling the flow of genetic information from DNA to mRNA...
s.