AP3S2 (sigma3B) is a small-chain subunit of the AP-3 adaptor-like complex, an assembly that also contains ~47, ~140, and ~160 kDa chains and localizes to the trans-Golgi network region and peripheral endosomal structures marked by the transferrin receptor PMID:9118953. Within this complex, AP-3 engages tyrosine-based sorting signals such as the YQRL motif of TGN38 through its p47A medium chain, placing AP3S2 in the machinery that recognizes sorting determinants for intracellular protein trafficking PMID:9118953. Beyond its role as an AP-3 subunit, no further mechanistic detail of AP3S2's own activity has been characterized in the available corpus.
| Year | Confidence | Finding | PMIDs | Journal |
|---|---|---|---|---|
| 1997 | High | AP3S2 (sigma3B) is a small chain component of the AP-3 adaptor-like complex, which also contains proteins of ~47, ~140, and ~160 kDa. The AP-3 complex localizes to the TGN region and peripheral structures containing the transferrin receptor, as determined by immunofluorescence microscopy. | PMID:9118953 | The EMBO journal |
| 1997 | Medium | The AP-3 complex containing AP3S2 (sigma3B) is involved in recognition of tyrosine-based sorting signals (YQRL from TGN38), mediated through the p47A medium chain subunit of the complex. | PMID:9118953 | The EMBO journal |
| 2024 | Low | AP3S2 was identified as a fusion partner with NTRK3 (AP3S2-NTRK3 fusion) in a patient with malignant melanoma, creating an oncogenic driver that was clinically responsive to a TRK inhibitor (BPI-28592). | PMID:39256512 | NPJ precision oncology |