Lipotoxicity impairs proinsulin processing by inhibiting the acidification of secretory granules by V-ATPase.

ABSTRACT: ATP6V0d1 is a subunit of the vacuolar H+-ATPase (V-ATPase) complex and plays an important role in the regulation of secretory granule acidification and insulin processing in pancreatic β-cells. To identify the S-palmitoylation site of ATP6V0d1, proteomic analysis was performed using MIN6 cells. Protein S-palmitoylation was labeled using the RapidSPALM kit (BioDynamics), in which palmitoylated cysteine residues were substituted with MfTag. Proteins were separated by SDS-PAGE, and a gel band exhibiting an approximately 5 kDa upward shift, corresponding to MfTag-labeled ATP6V0d1, was excised and subjected to in-gel digestion followed by LC-MS/MS analysis. During sample preparation, MfTag-modified cysteine residues were converted to carbamidomethylated cysteines by iodoacetamide treatment. Peptides containing the modified cysteine residues were used to identify candidate S-palmitoylation sites. LC-MS/MS analysis identified a peptide containing modified Cys39, suggesting that Cys39 is a candidate S-palmitoylation site of ATP6V0d1.

ORGANISM(S): Mus Musculus (mouse)

SUBMITTER: Hirotaka Watada 

PROVIDER: PXD080413 | JPOST Repository | Thu Oct 01 00:00:00 GMT+01:00 2026

REPOSITORIES: jPOST