Fluorescently-labeled fimbrin decorates a dynamic actin filament network in live plant cells

Planta. 2001 Jul;213(3):390-5. doi: 10.1007/s004250000494.


Recently it has been established, through a detailed biochemical analysis, that recombinant Arabidopsis thaliana fimbrin 1 (AtFim1) is a member of the fimbrin/plastin family of actin filament bundling or cross-linking proteins [D.R. Kovar et al. (2000) Plant J 24:625-636]. To determine whether AtFim1 can function as an F-actin-binding protein in the complex environment of the plant cell cytoplasm, we created a fluorescent protein analog and introduced it by microinjection into live Tradescantia virginiana L. stamen hair cells. AtFim1 derivatized with Oregon Green 488 had biochemical properties similar to unlabeled fimbrin, including the Kd value for binding to plant F-actin and the ability to cross-link filaments into higher-order structures. Fluorescent-fimbrin decorated an array of fine actin filaments in the cortical cytoplasm of stamen hair cells, which were shown with time-course studies to be highly dynamic. These data establish AtFim1 as a bona fide member of the fimbrin/plastin family, and represent the first use of a plant actin-binding protein as a powerful cytological tool for tracking the spatial and temporal redistribution of actin filaments in individual cells.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Actin Cytoskeleton
  • Actins / isolation & purification
  • Actins / metabolism
  • Carrier Proteins / chemistry
  • Carrier Proteins / metabolism
  • Cell Survival
  • Fluorescent Dyes / chemistry
  • Fluorescent Dyes / metabolism
  • Magnoliopsida / chemistry
  • Magnoliopsida / genetics
  • Magnoliopsida / metabolism*
  • Membrane Glycoproteins / chemistry
  • Membrane Glycoproteins / isolation & purification
  • Membrane Glycoproteins / metabolism*
  • Microfilament Proteins / chemistry
  • Microfilament Proteins / isolation & purification
  • Microfilament Proteins / metabolism*
  • Plant Stems / chemistry
  • Plant Stems / genetics
  • Plant Stems / metabolism
  • Pollen / chemistry


  • Actins
  • Carrier Proteins
  • F-actin-binding proteins
  • Fluorescent Dyes
  • Membrane Glycoproteins
  • Microfilament Proteins
  • plastin