Interactions in the pollen-specific receptor-like kinases-containing signaling network

Eur J Cell Biol. 2010 Dec;89(12):917-23. doi: 10.1016/j.ejcb.2010.08.002. Epub 2010 Sep 15.

Abstract

The pollen-specific receptor-like kinases (PRKs) from Solanum lycopersicum, LePRK1 and LePRK2, are believed to be involved in the regulation of pollen germination and pollen tube growth. They appear to be part of a multimeric complex in which the transmembranic LePRKs presumably have a key position in transducing exogenous signals through the plasma membrane. Here, we focused on extra- and intracellular interactions involving the LePRKs. We show in yeast two-hybrid experiments a cross-interaction of putative PRK-ligands, the oligomerization of LePRK2 and a direct contact of LePRKs to activated Rho proteins of plants (ROPs). Moreover, we observed that pollen-specific RopGEFs, which catalyze ROP activation and may be regulated by PRK interaction, are active in vitro while autoinhibition seems to occur in vivo. We suggest that activation of RopGEFs as a checkpoint in PRK signal transduction is a more complex event including further components in planta. Our findings point to some new aspects in PRK-mediated signal transduction implying a LePRK2 complex with different signaling activity and a further direct control of LePRKs by activated ROP.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Lycopersicon esculentum / enzymology
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Pollen / genetics
  • Pollen / metabolism
  • Pollen Tube / genetics
  • Pollen Tube / metabolism
  • Protein Kinases / genetics
  • Protein Kinases / metabolism*
  • Protein Multimerization / genetics
  • Protein Multimerization / physiology
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism*
  • Two-Hybrid System Techniques
  • rho GTP-Binding Proteins / genetics
  • rho GTP-Binding Proteins / metabolism

Substances

  • Plant Proteins
  • Recombinant Proteins
  • Protein Kinases
  • rho GTP-Binding Proteins