HSP70 Binding Protein 21 (HBP21)

HBP21, a novel member of TPR motif family, as a potential chaperone of heat shock protein 70 in proliferative vitreoretinopathy and breast cancer. HBP21 isa novel human protein of unknown function having three tandem TPR motifs predicted by computational sequence analysis.

High expression of HBP21 in breast cancer and proliferative vitreoretinopathy (PVR) proliferative membrane and examined whether HBP21 could interact with Hsp70 using a yeast two-hybrid system and glutathione S-transferase pull-down assay. Previous studies have demonstrated the importance of Hsp70 C-terminal residues EEVD and PTIEEVD for interaction with TPR-containing proteins. HBP21 may be involved in the inhibition of progression and metastasis of tumor cells.