Acts as a chaperone for the angiogenic VEGF receptor KDR/VEGFR2, increasing its abundance by inhibiting its ubiquitination and degradation (By similarity). Inhibits the folding activity of the chaperonin-containing T-complex (CCT) which leads to inhibition of cytoskeletal actin folding (By similarity). Acts as a chaperone during heat shock alongside HSP90 and HSP40/70 chaperone complexes (PubMed:27496612). Modulates the activation of caspases during apoptosis (By similarity). Interacts (via thioredoxin fold region) with KDR/VEGFR2 (via juxtamembrane domain) (By similarity). Forms ternary complexes with the chaperonin CCT complex and actin substrate, leading to inhibition of actin folding (By similarity). Interacts with XIAP (via BIR 3 and RING domain) (By similarity). Interacts with HSP90AA1 and HSP90AB1 (PubMed:27496612). By heat shock. N-terminal methionine acetylation destabilizes the protein. Belongs to the phosducin family.