Synaptotagmin 13 an atypical member: from epithelial integrity to pancreatic endocrine morphogenesis

Date

Nov 27, 2017

Time

2:00 PM - 3:00 PM

Speaker

Mostafa Bakhti

Affiliation

Helmholtz Zentrum Munich, Institute of Diabetes and Regeneration Research, Germany

Language

en

Main Topic

Biologie

Other Topics

Biologie

Host

Alf Honigmann

Description

Synaptotagmin 13 (Syt13) is an atypical member of Synaptotagmin family of membrane-trafficking proteins that its function has not been elucidated yet. Recently we have identified Syt13 as a novel endocrine lineage signature during mouse pancreas development. Our data reveals an increase in Syt13 expression levels in endocrine cells compared to low level-expressing ductal progenitors. We found an apical enrichment of Syt13 associated with cortical filamentous actin (F-actin) during epithelial cell division, which is important for spindle positioning. Furthermore, we found the clustering of Syt13 in micro-domains on the apical plasma membrane associated with the F-actin-to-plasma membrane tethering protein, Ezrin. We propose that Syt13 modulates cortical actin dynamics in epithelial cells to maintain their integrity. During secondary transition of pancreas development, endocrine cells are generated and delaminated from the ductal epithelium to form clusters of islets of Langerhans. Upon formation endocrine cells undergo repolarization, to achieve front-rear polarity that coincides with their migration out of the ductal epithelium. Interestingly, Syt13 accumulates at the leading edge of delaminating cells, and endocrine cells lacking this protein fail to leave the ductal epithelium properly. Our data show an accumulation of adhesion molecules in delaminating endocrine cells in Syt13-KO mice indicating the possible involvement of this protein in polarity switch and adhesion remodeling during endocrine cell delamination.

Last modified: Nov 28, 2017, 8:50:47 AM