Nuclear export is evolutionarily conserved in CVC paired-like homeobox proteins and influences protein stability, transcriptional activation, and extracellular secretion

Mol Cell Biol. 2005 Apr;25(7):2573-82. doi: 10.1128/MCB.25.7.2573-2582.2005.

Abstract

Homeodomain transcription factors control a variety of essential cell fate decisions during development. To understand the developmental regulation by these transcription factors, we describe here the molecular analysis of paired-like CVC homeodomain protein (PLC-HDP) trafficking. Complementary experimental approaches demonstrated that PLC-HDP family members are exported by the Crm1 pathway and contain an evolutionary conserved leucine-rich nuclear export signal. Importantly, inactivation of the nuclear export signal enhanced protein stability, resulting in increased transactivation of transfected reporters and decreased extracellular secretion. In addition, PLC-HDPs harbor a conserved active nuclear import signal that could also function as a protein transduction domain. In our study, we characterized PLC-HDPs as mobile nucleocytoplasmic shuttle proteins with the potential for unconventional secretion and intercellular transfer. Nucleocytoplasmic transport may thus represent a conserved control mechanism to fine-tune the transcriptional activity of PLC-HDPs prerequisite for regulating and maintaining the complex expression pattern during development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Active Transport, Cell Nucleus
  • Animals
  • Biological Evolution*
  • Cell Line
  • Cell Nucleus / metabolism*
  • Exportin 1 Protein
  • Eye Proteins / genetics
  • Eye Proteins / metabolism
  • Homeodomain Proteins / chemistry*
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism*
  • Humans
  • Karyopherins / genetics
  • Karyopherins / metabolism
  • Mice
  • Nuclear Localization Signals
  • Phospholipases / chemistry
  • Phospholipases / metabolism
  • Protein Binding
  • Receptors, Cytoplasmic and Nuclear / genetics
  • Receptors, Cytoplasmic and Nuclear / metabolism
  • Signal Transduction
  • Transcriptional Activation*
  • Zebrafish
  • Zebrafish Proteins / genetics
  • Zebrafish Proteins / metabolism

Substances

  • Eye Proteins
  • Homeodomain Proteins
  • Karyopherins
  • Nuclear Localization Signals
  • Receptors, Cytoplasmic and Nuclear
  • Zebrafish Proteins
  • vsx1 protein, zebrafish
  • Phospholipases