Synaptotagmin-8 (SYT8)

Synaptotagmin-8 (SYT8) is a membrane protein belonging to the synaptotagmin family, characterized by C2 domains and involvement in the regulation of exocytosis in both neuronal and non-neuronal tissues[5][2][4]. While synaptotagmins generally function as Ca²⁺ sensors, SYT8 does not display canonical Ca²⁺-dependent activity but is crucial in coupling insulin gene activity to secretion in pancreatic islet cells[3][2]. SYT8 modulates secretory granule trafficking and release, significantly impacting insulin exocytosis and hormone secretion[4][3]. Its gene expression is controlled by long-range chromatin interactions with the insulin gene promoter in a glucose-dependent manner[2][3]. Beyond endocrine functions, increased SYT8 expression has been identified in several cancers (notably pancreatic and gastric), where it promotes tumor growth, migration, and metastasis through interactions with the SIRT1, ERRα, and TNNI2 signaling axis[1][2]. These features make SYT8 a molecular effector in secretory pathways and a candidate biomarker or therapeutic target in oncology[1][2].

Other names

Synaptotagmin-8SYT8SytVIIIDKFZp434K0322Synaptotagmin VIIIsynaptotagmin-8synaptotagmin VIIIsytVIII

Modulation of exocytosis and secretion via protein–protein interactions in the secretory machinery, especially through non-Ca²⁺-dependent mechanisms