Molecular identification and characterization of the Arabidopsis AtADF1, AtADF5 and AtADF6 genes

Actin depolymerizing factor (ADF) is a key regulator of the organization of the actin cytoskeleton during various cellular activities. We found that A DF genes in Arabidopsis form a large family consisting of at least nine mem bers, four of which were cloned and sequenced in this study. Comparison of genomic and cDNA sequences showed that the AtADF1, AtADF5, and AtADF6 genes all contain two introns at conserved positions. Analysis of transgenic Ara bidopsis plants carrying promoter-GUS fusion constructs revealed that AtADF 1 and AtADF6 are expressed in the vascular tissues of all organs, whereas e xpression of AtADF5 is restricted to the root tip meristem. GFP-AtADF1, GFP -AtADF5, and GFP-AtADF6 fusion proteins were found to bind to actin filamen ts in vivo, and to reorganize the actin cytoskeleton when transiently expre ssed in plant cells.