HGNC Approved Gene Symbol: PFDN1
Cytogenetic location: 5q31.3 Genomic coordinates (GRCh38) : 5:140,245,035-140,303,101 (from NCBI)
PFDN1 is a subunit of the heteromeric prefoldin complex that chaperones nascent actin (see 102560) and alpha- and beta-tubulin (see 602529 and 191130, respectively) chains pending their transfer to the cytosolic chaperonin containing TCP1 (186980) (CCT) complex (Hansen et al., 1999).
Molecular chaperones are proteins that assist in the correct folding of other proteins in the crowded molecular environment that exists in living cells. Vainberg et al. (1998) described the biochemical purification of a heterohexameric chaperone that they termed prefoldin. By analysis of prefoldin by reverse-phase HPLC, they identified 6 prefoldin polypeptides, and they identified the corresponding mammalian cDNA sequences, of which 4 were human, by sequence analysis. These 4 included PFDN1, which encodes a 122-amino acid protein. PFDN3 is identical to VBP1 (300133), whereas PFDN4 (604898) and PFDN5 (604899) encode a possible transcription factor and a MYC (190080)-binding protein, respectively.
Hansen et al. (1999) showed that prefoldin is involved in chaperoning nascent chains of the cytoskeletal proteins actin, alpha-tubulin, and beta-tubulin in HeLa cells and rabbit reticulocyte lysates. Prefoldin bound to actin chains after synthesis of the N-terminal 130 to 140 amino acids and to beta-tubulin after synthesis of about 250 amino acids. Prefoldin remained bound to the relatively unfolded actin and tubulin polypeptides until delivery of the full-length proteins to CCT for folding to their native states.
Stumpf (2024) mapped the PFDN1 gene to chromosome 5q31.3 based on an alignment of the PFDN1 sequence (GenBank BC003620) with the genomic sequence (GRCh38).
Hansen, W. J., Cowan, N. J., Welch, W. J. Prefoldin-nascent chain complexes in the folding of cytoskeletal proteins. J. Cell Biol. 145: 265-277, 1999. [PubMed: 10209023] [Full Text: https://doi.org/10.1083/jcb.145.2.265]
Stumpf, A. M. Personal Communication. Baltimore, Md. 08/16/2024.
Vainberg, I. E., Lewis, S. A., Rommelaere, H., Ampe, C., Vandekerckhove, J., Klein, H. L., Cowan, N. J. Prefoldin, a chaperone that delivers unfolded proteins to cytosolic chaperonin. Cell 93: 863-873, 1998. [PubMed: 9630229] [Full Text: https://doi.org/10.1016/s0092-8674(00)81446-4]