AMPD2 regulates GTP synthesis and is mutated in a potentially treatable neurodegenerative brainstem disorder

Cell. 2013 Aug 1;154(3):505-17. doi: 10.1016/j.cell.2013.07.005.

Abstract

Purine biosynthesis and metabolism, conserved in all living organisms, is essential for cellular energy homeostasis and nucleic acid synthesis. The de novo synthesis of purine precursors is under tight negative feedback regulation mediated by adenosine and guanine nucleotides. We describe a distinct early-onset neurodegenerative condition resulting from mutations in the adenosine monophosphate deaminase 2 gene (AMPD2). Patients have characteristic brain imaging features of pontocerebellar hypoplasia (PCH) due to loss of brainstem and cerebellar parenchyma. We found that AMPD2 plays an evolutionary conserved role in the maintenance of cellular guanine nucleotide pools by regulating the feedback inhibition of adenosine derivatives on de novo purine synthesis. AMPD2 deficiency results in defective GTP-dependent initiation of protein translation, which can be rescued by administration of purine precursors. These data suggest AMPD2-related PCH as a potentially treatable early-onset neurodegenerative disease.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • AMP Deaminase / chemistry
  • AMP Deaminase / genetics
  • AMP Deaminase / metabolism*
  • Animals
  • Brain Stem / pathology
  • Cerebellum / pathology
  • Child
  • Female
  • Guanosine Triphosphate / metabolism
  • Humans
  • Male
  • Mice
  • Mice, Knockout
  • Mutation
  • Neural Stem Cells / metabolism
  • Olivopontocerebellar Atrophies / genetics
  • Olivopontocerebellar Atrophies / metabolism*
  • Olivopontocerebellar Atrophies / pathology
  • Protein Biosynthesis
  • Purines / biosynthesis*
  • Saccharomyces cerevisiae / enzymology
  • Saccharomyces cerevisiae / metabolism

Substances

  • Purines
  • Guanosine Triphosphate
  • AMP Deaminase
  • AMPD2 protein, human

Associated data

  • GEO/GSE46615