| Autor: |
Julie Lacombe, Kevin Guo, Jessica Bonneau, Denis Faubert, Florian Gioanni, Alexis Vivoli, Sarah M. Muir, Soraya Hezzaz, Vincent Poitout, Mathieu Ferron |
| Jazyk: |
angličtina |
| Rok vydání: |
2023 |
| Předmět: |
|
| Zdroj: |
Cell Reports, Vol 42, Iss 5, Pp 112500- (2023) |
| Druh dokumentu: |
article |
| ISSN: |
2211-1247 |
| DOI: |
10.1016/j.celrep.2023.112500 |
| Popis: |
Summary: Vitamin K is a micronutrient necessary for γ-carboxylation of glutamic acids. This post-translational modification occurs in the endoplasmic reticulum (ER) and affects secreted proteins. Recent clinical studies implicate vitamin K in the pathophysiology of diabetes, but the underlying molecular mechanism remains unknown. Here, we show that mouse β cells lacking γ-carboxylation fail to adapt their insulin secretion in the context of age-related insulin resistance or diet-induced β cell stress. In human islets, γ-carboxylase expression positively correlates with improved insulin secretion in response to glucose. We identify endoplasmic reticulum Gla protein (ERGP) as a γ-carboxylated ER-resident Ca2+-binding protein expressed in β cells. Mechanistically, γ-carboxylation of ERGP protects cells against Ca2+ overfilling by diminishing STIM1 and Orai1 interaction and restraining store-operated Ca2+ entry. These results reveal a critical role of vitamin K-dependent carboxylation in regulation of Ca2+ flux in β cells and in their capacity to adapt to metabolic stress. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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