title: AtCAND1, a HEAT-repeat protein that participates in auxin signaling in Arabidopsis.
abstract: Auxin affects many aspects of plant growth and development. We previously used chemical genetics to dissect auxin-signaling mechanisms and identified a small molecule, sirtinol, that constitutively activated auxin signaling (Y. Zhao et al. [2003], Science 301: 1107-1110). Here we describe the isolation, characterization, and cloning of an Arabidopsis mutant Atcand1-1 that emerged from a genetic screen for mutants insensitive to sirtinol. Loss-of-function mutants of AtCAND1 were resistant to sirtinol and auxin, but not to gibberellins or brassinolide. Atcand1 displayed developmental phenotypes similar to those of axr1, namely, short petioles, downwardly curling leaves, short inflorescence, and reduced fertility. AtCAND1 is homologous to human CAND1, a protein that is composed almost entirely of HEAT-repeat units and has been implicated in regulating the assembly and disassembly of the SCF protein degradation machinery. Taken together with previous biochemical studies, this work helps to elucidate the roles of AtCAND1 in protein degradation and auxin signaling.
authors.affiliation: Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093-0116, USA.
authors.forename: Youfa
authors.initials: Y
authors.lastname: Cheng
authors.forename: Xinhua
authors.initials: X
authors.lastname: Dai
authors.forename: Yunde
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001549:Benzamides / Q000494:pharmacology; D060406:Brassinosteroids; D002777:Cholestanols / Q000494:pharmacology; D003001:Cloning, Molecular; D004351:Drug Resistance / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005875:Gibberellins / Q000494:pharmacology; D006801:Humans; D007210:Indoleacetic Acids / Q000378:metabolism* / Q000494:pharmacology; D009154:Mutation; D009284:Naphthols / Q000494:pharmacology; D010641:Phenotype; D010937:Plant Growth Regulators / Q000378:metabolism* / Q000494:pharmacology; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D013260:Steroids, Heterocyclic / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D001549:Benzamides; D060406:Brassinosteroids; C488785:CAND1 protein, Arabidopsis; C486317:CAND1 protein, human; D002777:Cholestanols; D005875:Gibberellins; D007210:Indoleacetic Acids; D009284:Naphthols; D010937:Plant Growth Regulators; D013260:Steroids, Heterocyclic; D014157:Transcription Factors; C439060:sirtinol; C023623:brassinolide