Synaptic defects in a Drosophila model of congenital muscular dystrophy

Yogesh Wairkar, Lee G. Fradkin, Jasprina N. Noordermeer, Aaron DiAntonio

Research output: Contribution to journalArticle

47 Citations (Scopus)

Abstract

The congenital muscular dystrophies present in infancy with muscle weakness and are often associated with mental retardation. Many of these inherited disorders share a common etiology: defective O-glycosylation of α-dystroglycan, a component of the dystrophin complex. Protein-O-mannosyl transferase 1 (POMT1) is the first enzyme required for the glycosylation of α-dystroglycan, and mutations in the POMT1 gene can lead to both Walker-Warburg syndrome (WWS) and limb girdle muscular dystrophy type 2K (LGMD2K). WWS is associated with severe mental retardation and major structural abnormalities in the brain; however, LGMD2K patients display a more mild retardation with no obvious structural defects in the brain. In a screen for synaptic mutants in Drosophila, we identified mutations in the Drosophila ortholog of POMT1, dPOMT1. Because synaptic defects are a plausible cause of mental retardation, we investigated the molecular and physiological defects associated with loss of dPOMT1 in Drosophila. In dPOMT1 mutants, there is a decrease in the efficacy of synaptic transmission and a change in the subunit composition of the postsynaptic glutamate receptors at the neuromuscular junction. We demonstrate that dPOMT1 is required to glycosylate the Drosophila dystroglycan ortholog Dg in vivo, and that this is the likely cause of these synaptic defects because (1) mutations in Dg lead to similar synaptic defects and (2) genetic interaction studies suggest that dPOMT1 and Dg function in the same pathway. These results are consistent with the model that dPOMT1-dependent glycosylation of Dg is necessary for proper synaptic function and raise the possibility that similar synaptic defects occur in the congenital muscular dystrophies.

Original languageEnglish (US)
Pages (from-to)3781-3789
Number of pages9
JournalJournal of Neuroscience
Volume28
Issue number14
DOIs
StatePublished - Apr 2 2008
Externally publishedYes

Fingerprint

Walker-Warburg Syndrome
Muscular Dystrophies
Dystroglycans
Drosophila
Transferases
Glycosylation
Intellectual Disability
Mutation
Dystrophin
Neuromuscular Junction
Muscle Weakness
Glutamate Receptors
Brain
Synaptic Transmission
Proteins
Enzymes
Genes

Keywords

  • Drosophila
  • Dystroglycan
  • Glutamate receptors
  • Muscular dystrophy
  • NMJ
  • POMT1

ASJC Scopus subject areas

  • Neuroscience(all)
  • Medicine(all)

Cite this

Synaptic defects in a Drosophila model of congenital muscular dystrophy. / Wairkar, Yogesh; Fradkin, Lee G.; Noordermeer, Jasprina N.; DiAntonio, Aaron.

In: Journal of Neuroscience, Vol. 28, No. 14, 02.04.2008, p. 3781-3789.

Research output: Contribution to journalArticle

Wairkar, Yogesh ; Fradkin, Lee G. ; Noordermeer, Jasprina N. ; DiAntonio, Aaron. / Synaptic defects in a Drosophila model of congenital muscular dystrophy. In: Journal of Neuroscience. 2008 ; Vol. 28, No. 14. pp. 3781-3789.
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