Syntaxin-17 (STX17)

Syntaxin-17 (STX17) is a tail-anchored Qa-SNARE (soluble NSF attachment protein receptor) protein with a pivotal role in mammalian macroautophagy, especially in mediating membrane fusion between autophagosomes and lysosomes to form autolysosomes and thus enable degradation and recycling of cytosolic material[1][3][4]. STX17 contains an N-terminal Habc domain, a Qa-SNARE motif, and two unique tandem transmembrane domains that anchor it to autophagosomal membranes[1][4]. Upon autophagy induction, STX17 is recruited from the cytosol or Golgi to mature autophagosomes, where, in concert with autophagic SNAREs SNAP29 (Qbc-SNARE) and VAMP8 (R-SNARE), it forms a SNARE complex that fuses autophagosomes to lysosomes[1][4]. STX17 also interacts with proteins such as members of the ATG8 family (notably GABARAP), FIP200, and ATG13, and its function is regulated by phosphorylation (notably by TBK1 at serine 202) and by the microtubule-associated protein MAP1B-LC1[2][5]. In addition to its canonical role in membrane fusion during autophagy, STX17 has regulatory roles in autophagy initiation, potential roles in mitochondrial division (through Drp1 recruitment), and lipid droplet dynamics in some species and cell types[3][5]. Defects in STX17-mediated autophagy are implicated in neurodegenerative and age-related diseases, although STX17 itself is not currently a direct drug target and is not established as a clinical biomarker[2][5].

Other names

Syntaxin 17syntaxin-17FLJ20651STX17Syx17SYX-17 (nematodes)