PXD079191-1

PXD079191 is an original dataset announced via ProteomeXchange.

Title	Hexosamine Pathway Disruption by GFPT1 Loss Drives Coordinated Defects in Glycosylation, Autophagy, and Trafficking
Description	Gfpt1, the rate limiting enzyme of the hexosamine biosynthetic pathway (HBP), provides the UDP-GlcNAc required for protein glycosylation. Biallelic mutations in GFPT1 cause congenital myasthenic syndromes (GFPT1-CMS), yet the molecular mechanisms linking impaired glycosylation to skeletal muscle dysfunction remain incompletely understood. Here, we combine cellular models of inducible Gfpt1 knockdown and a muscle-specific Gfpt1 knockout mouse (Gfpt1Tm1d/Tm1d) with whole-cell proteomics, immunoblot studies and secretomics to define glycosylation-dependent defects in intracellular trafficking, ER stress signaling and autophagy. Global proteomic profiling of Gfpt1-deficient myoblasts revealed marked downregulation of protein trafficking pathways and impaired secretion of key muscle cargo proteins, including Srgn. Loss of GFPT1 reduced both high–molecular weight glycosylated SRGN and its core protein, accompanied by intracellular retention and decreased secretion. These trafficking defects coincided with robust activation of the unfolded protein response (UPR), evidenced by increased Xbp1 expression and accumulation of spliced Xbp1s across pharmacologic, cellular, and mouse models of GFPT1 deficiency. Converging evidence from proteomics, immunoblotting, and immunofluorescence demonstrated impaired autophagy, including increased LC3 II accumulation, elevated p62/SQSTM1 levels, and enhanced p62 positive puncta in both myoblasts and Gfpt1-deficient skeletal muscle. Soluble/insoluble fractionation further confirmed p62 accumulation, indicating defective autophagic flux and buildup of aggregated cargo. Together, these findings identify a glycosylation dependent failure in protein trafficking that triggers ER stress, UPR activation, and autophagy impairment in Gfpt1-deficient skeletal muscle. This mechanistic cascade provides a unifying explanation for muscle pathology in GFPT1 associated congenital myasthenic syndromes and suggests that restoring glycosylation or improving proteostasis may represent viable therapeutic approaches.
HostingRepository	PRIDE
AnnounceDate	2026-08-04
AnnouncementXML	Submission_2026-08-04_00:21:30.147.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Andreas Hentschel
SpeciesList	scientific name: Mus musculus (Mouse); NCBI TaxID: NEWT:10090;
ModificationList	iodoacetamide derivatized residue
Instrument	Q Exactive HF

Revision	Datetime	Status	ChangeLog Entry
0	2026-06-02 13:14:25	ID requested
⏵ 1	2026-08-04 00:21:30	announced

10.3390/BIOM16070966;

submitter keyword: Congenital Myasthenic Syndrome, Autophagy, Trafficking, GFPT1

Prof. Dr. Albert Sickmann
contact affiliation	Proteomics, Leibniz-Institut für analytische Wissenschaften -ISAS - e.V., Germany
contact email	albert.sickmann@isas.de
lab head
Andreas Hentschel
contact affiliation	Leibniz Institut für Analytische Wissenschaften
contact email	andreas.hentschel@isas.de
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD079191
     1. Label: PRIDE project
     2. Name: Hexosamine Pathway Disruption by GFPT1 Loss Drives Coordinated Defects in Glycosylation, Autophagy, and Trafficking