9.B.87.5.1
All-trans retinoic acid-induced differentiation factor, ATRAID or APR3 with 229 aas and 2 TMSs, N- and C-terminal. It promotes osteoblast cell differentiation and terminal mineralization and plays a role in inducing cell cycle arrest via inhibiting CCND1 expression in the all-trans-retinoic acid (ATRA) signal pathway. In osteoclasts, it forms a transporter complex with ATRAID for nitrogen-containing-bisphophonates (N-BPs) and is required for releasing N-BP molecules that have trafficked to lysosomes through fluid-phase endocytosis into the cytosol (Yu et al. 2018).  APR3 (Apoptosis-related protein 3) plays roles in cancer, affecting apoptosis, autophagy, oxidative stress, and cancer therapy (Zhang et al. 2023). APR3 is located in lysosomal membranes where it contributes to lysosomal activity.