Prefoldin Subunit 4 (PFDN4)

Prefoldin subunit 4 is a member of the prefoldin beta subunit family. The encoded protein is one of six subunits of prefoldin, a molecular chaperone complex that binds and stabilizes newly synthesized polypeptides, thereby allowing them to fold correctly. The complex, consisting of two alpha and four beta subunits, forms a double beta barrel assembly with six protruding coiled-coils. Sequence analysis of the C1 cDNA predicted a 130-amino acid protein with a helix-loop-helix domain, indicating that it might be a transcription factor. Northern blot analysis revealed expression of 0.6- and 0.8-kb transcripts which peaked in the early G1 phase in normal and SV40T-immortalized fibroblast cell lines.