TAF1
Encyclopedia
Transcription initiation factor TFIID subunit 1, also known as transcription initiation factor TFIID 250 kDa subunit (TAFII-250) or TBP-associated factor 250 kDa (p250), is a protein
that in humans is encoded by the TAF1 gene
.
by RNA polymerase II
requires the activities of more than 70 polypeptides. The protein that coordinates these activities is the basal transcription factor TFIID
, which binds to the core promoter to position the polymerase properly, serves as the scaffold for assembly of the remainder of the transcription complex, and acts as a channel for regulatory signals. TFIID is composed of the TATA-binding protein (TBP) and a group of evolutionarily conserved proteins known as TBP-associated factors or TAFs. TAFs may participate in basal transcription, serve as coactivators
, function in promoter recognition or modify general transcription factors (GTFs) to facilitate complex assembly and transcription initiation. This gene encodes the largest subunit of TFIID. This subunit binds to core promoter sequences encompassing the transcription start site. It also binds to activators and other transcriptional regulators, and these interactions affect the rate of transcription initiation. This subunit contains two independent protein kinase
domains at the N and C-terminals, but also possesses acetyltransferase
activity and can act as a ubiquitin
-activating/conjugating enzyme. Two transcripts encoding different isoforms have been identified for this gene.
with Casein kinase 2, alpha 1, TATA binding protein
, Cyclin D1
, Retinoblastoma protein
, TAF7
, GTF2F1
and UBTF
.
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
that in humans is encoded by the TAF1 gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
.
Function
Initiation of transcriptionTranscription (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...
by 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...
requires the activities of more than 70 polypeptides. The protein that coordinates these activities is the basal transcription factor TFIID
Transcription Factor II D
RNA polymerase II holoenzyme is a form of eukaryotic RNA polymerase II that is recruited to the promoters of protein-coding genes in living cells. It consists of RNA polymerase II, a subset of general transcription factors, and regulatory proteins known as SRB proteins...
, which binds to the core promoter to position the polymerase properly, serves as the scaffold for assembly of the remainder of the transcription complex, and acts as a channel for regulatory signals. TFIID is composed of the TATA-binding protein (TBP) and a group of evolutionarily conserved proteins known as TBP-associated factors or TAFs. TAFs may participate in basal transcription, serve as coactivators
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....
, function in promoter recognition or modify general transcription factors (GTFs) to facilitate complex assembly and transcription initiation. This gene encodes the largest subunit of TFIID. This subunit binds to core promoter sequences encompassing the transcription start site. It also binds to activators and other transcriptional regulators, and these interactions affect the rate of transcription initiation. This subunit contains two independent protein kinase
Protein kinase
A protein kinase is a kinase enzyme that modifies other proteins by chemically adding phosphate groups to them . Phosphorylation usually results in a functional change of the target protein by changing enzyme activity, cellular location, or association with other proteins...
domains at the N and C-terminals, but also possesses acetyltransferase
Acetyltransferase
Acetyltransferase is a type of transferase enzyme that transfers an acetyl group.Examples include:* Histone acetyltransferases including CBP histone acetyltransferase* Choline acetyltransferase* Chloramphenicol acetyltransferase...
activity and can act as a ubiquitin
Ubiquitin
Ubiquitin is a small regulatory protein that has been found in almost all tissues of eukaryotic organisms. Among other functions, it directs protein recycling.Ubiquitin can be attached to proteins and label them for destruction...
-activating/conjugating enzyme. Two transcripts encoding different isoforms have been identified for this gene.
Interactions
TAF1 has been shown to interactProtein-protein interaction
Protein–protein interactions occur when two or more proteins bind together, often to carry out their biological function. Many of the most important molecular processes in the cell such as DNA replication are carried out by large molecular machines that are built from a large number of protein...
with Casein kinase 2, alpha 1, TATA binding protein
TATA Binding Protein
The TATA-binding protein is a general transcription factor that binds specifically to a DNA sequence called the TATA box. This DNA sequence is found about 35 base pairs upstream of the transcription start site in some eukaryotic gene promoters...
, Cyclin D1
Cyclin D1
G1/S-specific cyclin-D1 is a protein that in humans is encoded by the CCND1 gene.Immunohistochemical staining of cyclin D1 antibodies is used to diagnose mantle cell lymphoma.-Interactions:...
, Retinoblastoma protein
Retinoblastoma protein
The retinoblastoma protein is a tumor suppressor protein that is dysfunctional in the majority types of cancer. One highly studied function of pRb is to prevent excessive cell growth by inhibiting cell cycle progression until a cell is ready to divide...
, TAF7
TAF7
Transcription initiation factor TFIID subunit 7 is a protein that in humans is encoded by the TAF7 gene.-Interactions:TAF7 has been shown to interact with TAF15, TAF1 and TATA binding protein.-External links:...
, GTF2F1
GTF2F1
General transcription factor IIF subunit 1 is a protein that in humans is encoded by the GTF2F1 gene.-Interactions:GTF2F1 has been shown to interact with TAF1, HNRPU, GTF2H4, CTDP1, TATA binding protein, POLR2A, MED21, TAF11, Serum response factor and Transcription Factor II B.-Further reading:...
and UBTF
UBTF
Nucleolar transcription factor 1 is a protein that in humans is encoded by the UBTF gene.-Interactions:UBTF has been shown to interact with Casein kinase 2, alpha 1, TAF1C, Retinoblastoma protein and TAF1.-Further reading:...
.