Abstract

Neuronostatin (NST) is a recently described peptide that is produced from the somatostatin preprohormone in pancreatic α-cells. NST has been shown to increase glucagon secretion from primary rat pancreatic islets in low-glucose conditions. Here, we demonstrate that NST increases proglucagon message in α-cells and identify a potential mechanism for NST's cellular activities, including the phosphorylation of PKA following activation of the G protein-coupled receptor, GPR107. GPR107 is abundantly expressed in the pancreas, particularly, in rodent and human α-cells. Compromise of GPR107 in pancreatic α-cells results in failure of NST to increase PKA phosphorylation and proglucagon mRNA levels. We also demonstrate colocalization of GPR107 and NST on both mouse and human pancreatic α-cells. Taken together with our group's observation that NST infusion in conscious rats impairs glucose clearance in response to a glucose challenge and that plasma levels of the peptide are elevated in the fasted compared with the fed or fasted-refed state, these studies support the hypothesis that endogenous NST regulates islet cell function by interacting with GPR107 and initiating signaling in glucagon-producing α-cells.

Department(s)

Biological Sciences

Publication Status

Open Access

Comments

National Institute of Diabetes and Digestive and Kidney Diseases, Grant R01DK052194

Keywords and Phrases

CAMP-independent PKA activation; Glucagon; Glucose homeostasis; GPR107; Islet function; Neuronostatin

International Standard Serial Number (ISSN)

1522-1490; 0363-6119

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2025 American Physiological Society, All rights reserved.

Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Publication Date

01 Jan 2016

PubMed ID

26561648

Download

Full Text Link

Included in

Biology Commons

Share

 
COinS