Autophagy related protein 9B (ATG9B)

Autophagy related protein 9B (ATG9B) is a vertebrate-specific, multi-spanning membrane protein that functions as a lipid scramblase and is crucial for autophagosomal membrane expansion by mediating phospholipid distribution during autophagosome formation[1][3]. While less ubiquitously expressed than its paralog ATG9A, ATG9B is particularly enriched in tissues like placenta and pituitary gland, with specialized roles in autophagy and possible compensatory activity when ATG9A is absent[1]. ATG9B cycles between the preautophagosomal structure and cytoplasmic vesicle pools, supplying membrane material vital for autophagosome biogenesis. Additionally, it modulates focal adhesion assembly and cell invasion through mechanisms that can be independent of autophagy, as evidenced in colorectal cancer where high ATG9B expression is linked with metastasis and poor patient prognosis[2]. Loss or mutation of ATG9B has been associated with various cancers and disorders reflecting its regulatory roles in both autophagic and non-autophagic processes[3].

Other names

ATG9BAutophagy-linked gene 9BAutophagy related 9BAutophagy-related protein 9B