Regulation of the pollen-specific actin-depolymerizing factor LIADF1

EG Allwood, RG Anthony, AP Smertenko, S Reichelt, BK Drobak, JH Doonan, AG Weeds, PJ Hussey*

*Corresponding author for this work

Research output: Contribution to journalArticle

124 Citations (Scopus)

Abstract

Pollen tube growth is dependent on a dynamic actin cytoskeleton, suggesting that actin-regulating proteins are involved. We have examined the regulation of the lily pollen-specific actin-depolymerizing factor (ADF) LIADF1. Its actin binding and depolymerizing activity is pH sensitive, inhibited by certain phosphoinositides, but not controlled by phosphorylation. Compared with its F-actin binding properties, its low activity in depolymerization assays has been used to explain why pollen ADF decorates F-actin in pollen grains. This low activity is incompatible with a role in increasing actin dynamics necessary to promote pollen tube growth. We have identified a plant homolog of actin-interacting protein, AIP1, which enhances the depolymerization of F-actin in the presence of LIADF1 by similar to60%. Both pollen ADF and pollen AIP1 bind F-actin in pollen grains but are mainly cytoplasmic in pollen tubes. Our results suggest that together these proteins remodel actin filaments as pollen grains enter and exit dormancy.

Original languageEnglish
Pages (from-to)2915-2927
Number of pages13
JournalThe Plant Cell
Volume14
Issue number11
DOIs
Publication statusPublished - Nov 2002

Keywords

  • COFILIN PHOSPHORYLATION
  • F-ACTIN
  • PHOSPHOINOSITIDES
  • DYNAMICS
  • ARABIDOPSIS
  • SEVERING PROTEIN
  • ANGIOSPERM POLLEN
  • IN-VIVO
  • FILAMENTS
  • PROTEIN-KINASE

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