β-Cell keratin 8 maintains islet mechanical integrity, mitochondrial ultrastructure, and β-cell glucose transporter 2 plasma membrane targeting.

Islet β-cell dysfunction is an underlying factor for type I diabetes (T1D) development. Insulin sensing and secretion are tightly regulated in β-cells at multiple subcellular levels. The epithelial intermediate filament (IF) protein keratin (K) 8 is the main β-cell keratin, constituting the filament network with K18.