Programmed cell death protein 6 (PDCD6)

Calcium sensor that plays an integral role in processes like endoplasmic reticulum (ER)-Golgi vesicular transport, endosomal biogenesis or membrane repair. Acts as an adapter that bridges unrelated proteins or stabilizes weak protein-protein complexes in response to calcium: calcium-binding triggers exposure of apolar surface, promoting interaction with unique sets of proteins owing to 3 distinct hydrophobic pockets, leading to translocation to membranes (PubMed:20691033, PubMed:25667979).

Involved in ER-Golgi transport by encouraging the association between PDCD6IP and TSG101, thereby bridging together the ESCRT- III and ESCRT-I complexes (PubMed:19520058). In response to cytosolic calcium increase, the heterodimer formed with PEF1 interacts with, and bridges together the BCR(KLHL12) complicated and SEC31 (SEC31A or SEC31B), boosting monoubiquitination of SEC31 and subsequent collagen export, which is required for neural crest specification (PubMed:27716508).