Host cell factor 1 (HCFC1, HCF1, or HCF-1), also known as VP16-accessory protein, is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
that in humans is encoded by the ''HCFC1''
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
Structure
HCF1 is a member of the highly conserved host cell factor family and encodes a protein with five
Kelch repeats, a
fibronectin-like motif, and six
HCF repeats, each of which contains a highly specific cleavage signal. This nuclear
transcription coregulator
In molecular biology and genetics, transcription coregulators are proteins that interact with transcription factors to either activate or repress the transcription of specific genes. Transcription coregulators that activate gene transcription ar ...
is
proteolytically cleaved at one or more of the six possible sites, resulting in the creation of an
N-terminal
The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the amin ...
chain and the corresponding
C-terminal
The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, carboxy tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When t ...
chain. The final form of this protein consists of noncovalently bound N- and C-terminal chains which interact through electrostatic forces.
Function
HCF1 is involved in control of the
cell cycle
The cell cycle, or cell-division cycle, is the sequential series of events that take place in a cell (biology), cell that causes it to divide into two daughter cells. These events include the growth of the cell, duplication of its DNA (DNA re ...
as well as having regulatory roles in a multitude of processes related to
transcription
Transcription refers to the process of converting sounds (voice, music etc.) into letters or musical notes, or producing a copy of something in another medium, including:
Genetics
* Transcription (biology), the copying of DNA into RNA, often th ...
. Additionally, work in model organisms point to HCF1 as being a putative
longevity
Longevity may refer to especially long-lived members of a population, whereas ''life expectancy'' is defined Statistics, statistically as the average number of years remaining at a given age. For example, a population's life expectancy at birth ...
determinant.
Alternatively
spliced variants that encode different protein isoforms have been described; however, not all variants have been fully characterized.
Mutations in this gene have been linked to disorders of the
cobalamine metabolism.
Interactions
Host cell factor C1 has been shown to
interact
Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization advocating for the legal and human rights of children with intersex traits. The organization was founded in 2006 and fo ...
with:
*
BAP1
BRCA1 associated protein-1 (ubiquitin carboxy-terminal hydrolase) is a deubiquitinating enzyme that in humans is encoded by the ''BAP1'' gene. ''BAP1'' encodes an 80.4 kDa nuclear-localizing protein with a ubiquitin carboxy-terminal hydrolase ( ...
,
*
CREB3
Cyclic AMP-responsive element-binding protein 3 is a protein that in humans is encoded by the ''CREB3'' gene.
This gene encodes a transcription factor that is a member of the leucine zipper family of DNA binding proteins. This protein binds to t ...
,
*
GABPA
GA-binding protein alpha chain is a protein that in humans is encoded by the ''GABPA'' gene.
Function
This gene encodes one of three GA-binding protein transcription factor subunits which functions as a DNA-binding subunit. Since this subun ...
,
*
HDAC1
Histone deacetylase 1 (HDAC1) is an enzyme that in humans is encoded by the ''HDAC1'' gene.
Function
Histone acetylation and deacetylation, catalyzed by multisubunit complexes, play a key role in the regulation of eukaryotic gene expression. ...
,
*
HDAC2
Histone deacetylase 2 (HDAC2) is an enzyme that in humans is encoded by the ''HDAC2'' gene. It belongs to the histone deacetylase class of enzymes responsible for the removal of acetyl groups from lysine residues at the N-terminal region of the ...
,
[
* MLL,][
* OGT,][
* ]PDCD2
Programmed cell death protein 2 is a protein that in humans is encoded by the ''PDCD2'' gene.
Function
This gene encodes a nuclear protein expressed in a variety of tissues. The rat homolog, Rp8, is transiently expressed in immature thymocytes ...
,
* POU2F1
POU domain, class 2, transcription factor 1 is a protein that in humans is encoded by the ''POU2F1'' gene.
Interactions
POU2F1 has been shown to interact with:
* EPRS,
* Glucocorticoid receptor,
* Glyceraldehyde 3-phosphate dehydrogenase, ...
,
* PPP1CA
Serine/threonine-protein phosphatase PP1-alpha catalytic subunit is an enzyme that in humans is encoded by the ''PPP1CA'' gene.
Function
The protein encoded by this gene is one of the three catalytic subunits of protein phosphatase 1 (PP1). P ...
,
* SIN3A
Paired amphipathic helix protein Sin3a is a protein that in humans is encoded by the ''SIN3A'' gene.
Function
The protein encoded by this gene is a transcriptional regulatory protein. It contains paired amphipathic helix (PAH) domains, whic ...
,
* SP1,
* SUDS3
Sin3 histone deacetylase corepressor complex component SDS3 is an enzyme that in humans is encoded by the ''SUDS3'' gene.
Function
SDS3 is a subunit of the histone deacetylase (see HDAC1; MIM 601241)-dependent SIN3A (MIM 607776) corepressor co ...
,[
* ]WDR5
WD repeat-containing protein 5 is a protein that in humans is encoded by the ''WDR5'' gene.
This gene encodes a member of the WD repeat protein family. WD repeats are minimally conserved regions of approximately 40 amino acids typically bracketed ...
,[ and
* ZBTB17.]
References
Further reading
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{{refend
Kelch proteins