The E. coli heat-shock protein DnaJ is the founding member of a family of proteins that are associated with protein folding, complex assembly, and export. Prokaryotic and eukaryotic DnaJ homologs contain an approximately 70-amino acid J domain, which is thought to mediate interaction with 70-kD heat-shock proteins .
The HSPF2 gene is located approximately 250 bp centromeric of the VEGFB gene. The HSPF2 coding sequence is contained in 5 exons. The deduced 241-amino acid HSPF2 protein has a J domain followed by a predicted transmembrane domain. The human and mouse HSPF2 proteins are 71% identical. Northern blot analysis detected an approximately 1.4-kb HSPF2 transcript in all human cell lines examined.