Drosophila Larp associates with poly(A)-binding protein and is required for male fertility and syncytial embryo development

Dev Biol. 2009 Oct 1;334(1):186-97. doi: 10.1016/j.ydbio.2009.07.016. Epub 2009 Jul 22.

Abstract

As the influence of mRNA translation upon cell cycle regulation becomes clearer, we searched for genes that might specify such control in Drosophila. A maternal-effect lethal screen identified mutants in the Drosophila gene for Larp (La-related protein) which displayed maternal-effect lethality and male sterility. A role for La protein has already been implicated in mRNA translation whereas Larp has been proposed to regulate mRNA stability. Here we demonstrate that Larp exists in a physical complex with, and also interacts genetically with, the translation regulator poly(A)-binding protein (PABP). Most mutant alleles of pAbp are embryonic lethal. However hypomorphic pAbp alleles show similar meiotic defects to larp mutants. We find that larp mutant-derived syncytial embryos show a range of mitotic phenotypes, including failure of centrosomes to migrate around the nuclear envelope, detachment of centrosomes from spindle poles, the formation of multipolar spindle arrays and cytokinetic defects. We discuss why the syncytial mitotic cycles and male meiosis should have a particularly sensitive requirement for Larp proteins in regulating not only transcript stability but also potentially the translation of mRNAs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Animals
  • Cytoplasm / metabolism
  • Drosophila / embryology*
  • Drosophila / metabolism
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism*
  • Embryo, Nonmammalian / metabolism*
  • Embryonic Development / physiology*
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Larva / metabolism
  • Male
  • Meiosis
  • Mutation
  • Oocytes / metabolism
  • Poly(A)-Binding Proteins / metabolism*
  • RNA Interference
  • RNA Stability
  • RNA, Messenger / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*

Substances

  • Drosophila Proteins
  • Larp protein, Drosophila
  • Pabp protein, Drosophila
  • Poly(A)-Binding Proteins
  • RNA, Messenger
  • Transcription Factors
  • enhanced green fluorescent protein
  • Green Fluorescent Proteins