All-trans retinoic acid-induced differentiation factor (ATRAID)

All-trans retinoic acid-induced differentiation factor (ATRAID) is a glycosylated transmembrane protein found primarily in lysosomal, endosomal, and Golgi membranes, with highest expression of isoform C in human cells[2][5]. ATRAID regulates apoptosis, cell differentiation, and cell cycle arrest, in particular through cyclin D1 inhibition and promotion of osteoblast differentiation[6]. ATRAID is also essential for the activity of nitrogen-containing bisphosphonate drugs used to treat bone diseases, by permitting their release from lysosomes to the cytosol via a complex with SLC37A3[2]. The gene is implicated in hematopoietic development and may play roles in cancer biology and oxidative stress response, including retinal aging[3][4][6]. Multiple alternative transcripts exist, but primarily isoform C is detected as a stable protein; isoform A is rapidly degraded, and isoform B is not supported at the protein level[2]. Key domains in ATRAID include a Toll-like leucine-rich repeat and an EGF-like domain, supporting protein–protein interactions relevant to signal transduction and cellular trafficking[2]. ATRAID is not a classic receptor, enzyme, ion channel, or transcription factor, but is considered a membrane protein essential for specific drug responses and fundamental cellular processes[1][2].

Other names

APR3C2orf28HSPC013UNQ214/PRO240p18apoptosis-related protein 3APR-3PRO240

Required for release of bisphosphonates from the lysosome to cytosol (via complex formation with SLC37A3), May regulate cell proliferation via interaction with cell cycle proteins, May mediate osteoblast differentiation by interacting with NELL-1