A null mutation in inositol polyphosphate 4-phosphatase type I causes selective neuronal loss in weeble mutant mice

Neuron. 2001 Oct 25;32(2):203-12. doi: 10.1016/s0896-6273(01)00468-8.


Weeble mutant mice have severe locomotor instability and significant neuronal loss in the cerebellum and in the hippocampal CA1 field. Genetic mapping was used to localize the mutation to the gene encoding inositol polyphosphate 4-phosphatase type I (Inpp4a), where a single nucleotide deletion results in a likely null allele. The substrates of INPP4A are intermediates in a pathway affecting intracellular Ca(2+) release but are also involved in cell cycle regulation through binding the Akt protooncogene; dysfunction in either may account for the neuronal loss of weeble mice. Although other mutations in phosphoinositide enzymes are associated with synaptic defects without neuronal loss, weeble shows that Inpp4a is critical for the survival of a subset of neurons during postnatal development in mice.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alleles
  • Animals
  • Apoptosis
  • Ataxia / genetics
  • Calbindins
  • Calcium / metabolism
  • Cell Cycle / genetics
  • Cell Death / genetics
  • Cerebellum / chemistry
  • Cerebellum / pathology
  • Gene Deletion
  • Gene Expression
  • Hippocampus / pathology
  • In Situ Hybridization
  • In Situ Nick-End Labeling
  • Mice
  • Mice, Inbred C57BL
  • Mice, Neurologic Mutants
  • Molecular Sequence Data
  • Motor Activity
  • Mutation*
  • Neurons / pathology*
  • Phosphoric Monoester Hydrolases / genetics*
  • S100 Calcium Binding Protein G / analysis


  • Calbindins
  • S100 Calcium Binding Protein G
  • Phosphoric Monoester Hydrolases
  • phosphatidylinositol-3,4-bisphosphate 4-phosphatase
  • Calcium

Associated data

  • GENBANK/AF317838