RRC ID 6299
Author Finka A, Saidi Y, Goloubinoff P, Neuhaus JM, Zrÿd JP, Schaefer DG.
Title The knock-out of ARP3a gene affects F-actin cytoskeleton organization altering cellular tip growth, morphology and development in moss Physcomitrella patens.
Journal Cell Motil Cytoskeleton
Abstract The seven subunit Arp2/3 complex is a highly conserved nucleation factor of actin microfilaments. We have isolated the genomic sequence encoding a putative Arp3a protein of the moss Physcomitrella patens. The disruption of this ARP3A gene by allele replacement has generated loss-of-function mutants displaying a complex developmental phenotype. The loss-of function of ARP3A gene results in shortened, almost cubic chloronemal cells displaying affected tip growth and lacking differentiation to caulonemal cells. In moss arp3a mutants, buds differentiate directly from chloronemata to form stunted leafy shoots having differentiated leaves similar to wild type. Yet, rhizoids never differentiate from stem epidermal cells. To characterize the F-actin organization in the arp3a-mutated cells, we disrupted ARP3A gene in the previously described HGT1 strain expressing conditionally the GFP-talin marker. In vivo observation of the F-actin cytoskeleton during P. patens development demonstrated that loss-of-function of Arp3a is associated with the disappearance of specific F-actin cortical structures associated with the establishment of localized cellular growth domains. Finally, we show that constitutive expression of the P. patens Arp3a and its Arabidopsis thaliana orthologs efficiently complement the mutated phenotype indicating a high degree of evolutionary conservation of the Arp3 function in land plants.
Volume 65(10)
Pages 769-84
Published 2008-10-1
DOI 10.1002/cm.20298
PMID 18613119
MeSH Actins / chemistry Actins / metabolism* Base Sequence Bryopsida / cytology Bryopsida / genetics* Bryopsida / growth & development Cell Migration Assays Cells, Cultured Cytoskeleton / metabolism* Green Fluorescent Proteins / genetics Microfilament Proteins / genetics* Molecular Sequence Data Mutation Phenotype Phylogeny Plant Proteins / genetics* Protein Subunits / genetics* Reverse Transcriptase Polymerase Chain Reaction
Times Cited 21
WOS Category CELL BIOLOGY
Resource
Arabidopsis / Cultured plant cells, genes pda08187