Logo image
L-Arginine prevents cereblon-mediated ubiquitination of glucokinase and stimulates glucose-6-phosphate production in pancreatic beta-cells
Journal article   Open access   Peer reviewed

L-Arginine prevents cereblon-mediated ubiquitination of glucokinase and stimulates glucose-6-phosphate production in pancreatic beta-cells

Jaeyong Cho, Yukio Horikawa, Mayumi Enya, Jun Takeda, Yoichi Imai, Yumi Imai, Hiroshi Handa and Takeshi Imai
Communications biology, Vol.3(1), pp.497-497
09/08/2020
DOI: 10.1038/s42003-020-01226-3
PMCID: PMC7479149
PMID: 32901087
url
https://doi.org/10.1038/s42003-020-01226-3View
Published (Version of record) Open Access

Abstract

We sought to determine a mechanism by which L-arginine increases glucose-stimulated insulin secretion (GSIS) in beta -cells by finding a protein with affinity to L-arginine using arginine-immobilized magnetic nanobeads technology. Glucokinase (GCK), the key regulator of GSIS and a disease-causing gene of maturity-onset diabetes of the young type 2 (MODY2), was found to bind L-arginine. L-Arginine stimulated production of glucose-6-phosphate (G6P) and induced insulin secretion. We analyzed glucokinase mutants and identified three glutamate residues that mediate binding to L-arginine. One MODY2 patient with GCK(E442*) demonstrated lower C-peptide-to-glucose ratio after arginine administration. In beta -cell line, GCK(E442*) reduced L-arginine-induced insulin secretion compared with GCK(WT). In addition, we elucidated that the binding of arginine protects glucokinase from degradation by E3 ubiquitin ligase cereblon mediated ubiquitination. We conclude that L-arginine induces insulin secretion by increasing G6P production by glucokinase through direct stimulation and by prevention of degradation. Using arginine-immobilized magnetic nanobeads, Cho et al. show that glucokinase, the key regulator of glucose-stimulated insulin secretion, binds L-arginine, which protects glucokinase from ubiquitination-mediated degradation while inducing insulin secretion. This study provides mechanistic insights into how L-arginine increases insulin production.
Biology Life Sciences & Biomedicine Life Sciences & Biomedicine - Other Topics Multidisciplinary Sciences Science & Technology Science & Technology - Other Topics

Details

Metrics

Logo image