Host cell factor 1 (HCFC1, HCF1, or HCF-1), also known as VP16-accessory protein,[5] is a protein that in humans is encoded by the HCFC1 gene.[6][7]
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 is proteolytically cleaved at one or more of the six possible sites, resulting in the creation of an N-terminal chain and the corresponding C-terminal chain. The final form of this protein consists of noncovalently bound N- and C-terminal chains which interact through electrostatic forces.
HCF1 is involved in control of the cell cycle as well as having regulatory roles in a multitude of processes related to transcription. Additionally, work in model organisms point to HCF1 as being a putative longevity determinant.[8] Alternatively spliced variants that encode different protein isoforms have been described; however, not all variants have been fully characterized.[7]
Mutations in this gene have been linked to disorders of the cobalamine metabolism.[9]
Host cell factor C1 has been shown to interact with: