The function of Ensembl gene identifier ENSG00000133265 (HSPBP1, HSPA (Hsp70) binding protein 1) is as follows. Inhibits HSPA1A chaperone activity by changing the conformation of the ATP-binding domain of HSPA1A and interfering with ATP binding. Interferes with ubiquitination mediated by STUB1 and inhibits chaperone-assisted degradation of immature CFTR. {ECO:0000269|PubMed:10786638, ECO:0000269|PubMed:12651857, ECO:0000269|PubMed:15215316, ECO:0000269|PubMed:21247889, ECO:0000269|PubMed:9830037}.