Local activation of focal adhesion kinase orchestrates the positioning of presynaptic scaffold proteins and Ca2+ channel function to control glucose dependent insulin secretion

Internet publication

A developing understanding suggests that spatial compartmentalisation of components the glucose stimulus-secretion pathway in pancreatic β cells are critical in controlling insulin secretion. To investigate the mechanisms, we have developed live-cell sub-cellular imaging methods using the organotypic pancreatic slice. We demonstrate that the organotypic pancreatic slice, when compared with isolated islets, preserves intact β cell structure, and enhances glucose dependent Ca²⁺ responses and insulin secretion. Using the slice technique, we have discovered the essential role of local activation of integrins and the downstream component, focal adhesion kinase, in regulating β cells. Integrins and focal adhesion kinase are exclusively activated at the β cell capillary interface and using in situ and in vitro models we show their activation both positions presynaptic scaffold proteins, like ELKS and liprin, and regulates glucose dependent Ca²⁺ responses and insulin secretion. We conclude that focal adhesion kinase orchestrates the final steps of glucose dependent insulin secretion within the restricted domain where β cells contact the islet capillaries.

Authors: Hallahan, N; Deng, K; Jevon, D; Kumar, K; Tong, J

• Publication status: Accepted
• Peer review status: Reviewed (other)
• Publisher: bioRxiv
• Host title: Cold Spring Harbor Laboratory
• Publication date: 2021-12-23
• DOI: 10.1101/2021.12.21.473760
• Language: English
• Keywords: normal biological development and functioning; FFR; underpinning research; metabolic and endocrine; diabetes
• Subjects: Biological sciences; Biochemistry and cell biology