title: The Arabidopsis GNARLED gene encodes the NAP125 homolog and controls several actin-based cell shape changes.
abstract: In plants many aspects of cell shape regulation are controlled by actin-dependent processes. The ARP2/3 complex has been recognized as a regulator of actin organization. Mutations in genes encoding components of the ARP2/3 complex lead to cell shape defects in several cell types, including trichomes, epidermal pavement cells and hypocotyl cells. We show here that mutations in the GNARLED (GRL) gene cause a similar range of phenotypes. The GRL gene encodes the Arabidopsis homolog of NAP125, which in animals is known to act as one regulator of the ARP2/3-regulating complex WAVE-HSPC300. As an HSPC300 homolog is present in the Arabidopsis genome but no WAVE homolog has yet been found, the existence of a related regulation pathway was doubtful. Our finding that GRL encodes a putative regulator of the WAVE-HSPC300 complex, NAP125, combined with the phenotypic similarity between arp2/3 and grl mutants, provides evidence that the ARP2/3 complex is indeed regulated by the above mentioned pathway in Arabidopsis.
authors.affiliation: Botanical Institute, University of Köln, Gyrhofstrasse 15, 50931 Köln, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Zimmermann
authors.forename: R
authors.initials: R
authors.lastname: Saedler
authors.forename: M
authors.initials: M
authors.lastname: Mutondo
authors.forename: M
authors.initials: M
authors.lastname: Hulskamp
mesh_terms: D000199:Actins / Q000502:physiology*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D048430:Cell Shape; D017931:DNA Primers; D008969:Molecular Sequence Data; D010641:Phenotype; D017386:Sequence Homology, Amino Acid
chemical_list: D000199:Actins; D029681:Arabidopsis Proteins; D017931:DNA Primers; C492907:GNARLED protein, Arabidopsis