Interaction between LIS1 and doublecortin, two lissencephaly gene products

Hum Mol Genet. 2000 Sep 22;9(15):2205-13. doi: 10.1093/oxfordjournals.hmg.a018911.

Abstract

Mutations in either LIS1 or DCX are the most common cause for type I lissencephaly. Here we report that LIS1 and DCX interact physically both in vitro and in vivo. Epitope-tagged DCX transiently expressed in COS cells can be co-immunoprecipitated with endogenous LIS1. Furthermore, endogenous DCX could be co-immunoprecipitated with endogenous LIS1 in embryonic brain extracts, demonstrating an in vivo association. The two protein products also co-localize in transfected cells and in primary neuronal cells. In addition, we demonstrate homodimerization of DCX in vitro. Using fragments of both LIS1 and DCX, the domains of interaction were mapped. LIS1 and DCX interact with tubulin and microtubules. Our results suggest that addition of DCX and LIS1 to tubulin enhances polymerization in an additive fashion. In in vitro competition assays, when LIS1 is added first, DCX competes with LIS1 in its binding to microtubules, but when DCX is added prior to the addition of LIS1 it enhances the binding of LIS1 to microtubules. We conclude that LIS1 and DCX cross-talk is important to microtubule function in the developing cerebral cortex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 1-Alkyl-2-acetylglycerophosphocholine Esterase
  • Animals
  • Blotting, Northern
  • Blotting, Western
  • Brain / metabolism
  • COS Cells
  • Cell Line
  • Chlorocebus aethiops
  • Dimerization
  • Embryo, Mammalian
  • Mice
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism*
  • Microtubules / metabolism
  • Neuropeptides / genetics
  • Neuropeptides / metabolism*
  • Polymerase Chain Reaction
  • Precipitin Tests
  • Protein Binding
  • Protein Structure, Tertiary
  • Rats
  • Tissue Extracts
  • Transfection
  • Tubulin / metabolism

Substances

  • Microtubule-Associated Proteins
  • Neuropeptides
  • Tissue Extracts
  • Tubulin
  • doublecortin protein
  • 1-Alkyl-2-acetylglycerophosphocholine Esterase
  • Pafah1b1 protein, mouse