title: Early auxin-induced genes encode short-lived nuclear proteins.
abstract: The plant growth hormone indoleacetic acid (IAA) transcriptionally activates gene expression in plants. Some of the genes whose expression is induced by IAA encode a family of proteins in pea (PS-IAA4 and PS-IAA6) and Arabidopsis (IAA1 and IAA2) that contain putative nuclear localization signals that direct a beta-glucuronidase reporter protein into the nucleus. Pulse-chase and immunoprecipitation experiments have defined the t1/2 of the PS-IAA4 and PS-IAA6 proteins to be 8 and 6 min, respectively. Their most prominent feature is the presence of a beta alpha alpha motif similar to the beta-sheet DNA-binding domain found in prokaryotic repressors of the Arc family. Based on these data, we suggest that plant tissues express short-lived nuclear proteins as a primary response to IAA. We propose that these proteins act as activators or repressors of genes responsible for mediating the various auxin responses.
authors.affiliation: Plant Gene Expression Center, Albany, CA 94710.
authors.forename: S
authors.initials: S
authors.lastname: Abel
authors.forename: P W
authors.initials: PW
authors.lastname: Oeller
authors.forename: A
authors.initials: A
authors.lastname: Theologis
mesh_terms: D000595:Amino Acid Sequence; D016384:Consensus Sequence; D007887:Fabaceae / Q000235:genetics*; D007210:Indoleacetic Acids / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism; D010946:Plants, Medicinal; D017433:Protein Structure, Secondary; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism
chemical_list: D007210:Indoleacetic Acids; D009687:Nuclear Proteins; D010940:Plant Proteins; D014157:Transcription Factors