Synaptotagmin 13 drives pancreatic endocrine cell egression and islet morphogenesis: Affinity purification

ABSTRACT: Identification of protein complexes for the synaptotagmin 13 protein from MDCK cells by Strep affinity purificaiton and LFQ mass spectrometry. Epithelial cell egression is important for organ development and cell differentiation, but also drives cancer metastasis. The tightly connected pancreatic epithelial differentiation and morphogenesis generate islets of Langerhans. However, the morphogenetic drivers and molecular mechanisms are largely unresolved. Here we identify the uncharacterized Synaptotagmin 13 (Syt13) as a major regulator of endocrine cell egression and islet morphogenesis and differentiation. We detected upregulation of Syt13 in endocrine precursors that associates with increased expression of several unique cytoskeletal components. High-resolution imaging reveals a previously unidentified apical-basal to front-rear repolarization during endocrine cell egression. Strikingly, Syt13 directly interacts with acetylated tubulin and phosphoinositide phospholipids to be recruited to the leading edge of egressing cells. Knockout of Syt13 discloses the impairment in endocrine cell egression and skews the α-to-β-cell ratio. At mechanistic levels, Syt13 regulates protein endocytosis to remodel the basement membrane and modulate cell-matrix adhesion at the leading edge of egressing endocrine cells. Altogether, these findings implicate that Ca2+-independent atypical Syt13 vesicular protein functions in regulating cell polarity to orchestrate endocrine cell egression and tissue morphogenesis.

INSTRUMENT(S): Orbitrap Fusion

ORGANISM(S): Canis Lupus X Canis Lupus Familiaris

TISSUE(S): Epithelial Cell, Cell Culture

DISEASE(S): Disease Free

SUBMITTER: Karsten Boldt  

LAB HEAD: Dr. Karsten Boldt

PROVIDER: PXD026698 | Pride | 2023-12-28

REPOSITORIES: Pride