title: The Arabidopsis cupin domain protein AtPirin1 interacts with the G protein alpha-subunit GPA1 and regulates seed germination and early seedling development.
abstract: Heterotrimeric G proteins are implicated in diverse signaling processes in plants, but the molecular mechanisms of their function are largely unknown. Finding G protein effectors and regulatory proteins can help in understanding the roles of these signal transduction proteins in plants. A yeast two-hybrid screen was performed to search for proteins that interact with Arabidopsis G protein alpha-subunit (GPA1). One of the identified GPA1-interacting proteins is the cupin-domain protein AtPirin1. Pirin is a recently defined protein found because of its ability to interact with a CCAAT box binding transcription factor. The GPA1-AtPirin1 interaction was confirmed in an in vitro binding assay. We characterized two atpirin1 T-DNA insertional mutants and established that they display a set of phenotypes similar to those of gpa1 mutants, including reduced germination levels in the absence of stratification and an abscisic acid-imposed delay in germination and early seedling development. These data indicate that AtPirin1 likely functions immediately downstream of GPA1 in regulating seed germination and early seedling development.
authors.affiliation: Laboratory for Molecular Biology, Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
authors.forename: Yevgeniya R
authors.initials: YR
authors.lastname: Lapik
authors.forename: Lon S
authors.initials: LS
authors.lastname: Kaufman
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D017124:Conserved Sequence / Q000235:genetics; D046508:Culture Techniques; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D044385:GTP-Binding Protein alpha Subunits / Q000235:genetics / Q000378:metabolism; D044388:GTP-Binding Protein gamma Subunits / Q000235:genetics* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018525:Germination / Q000187:drug effects; D047908:Intracellular Signaling Peptides and Proteins; D008027:Light; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009154:Mutation; D011485:Protein Binding; D025941:Protein Interaction Mapping; D012098:Reproduction / Q000235:genetics / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; C478977:At3g59260 protein, Arabidopsis; D002352:Carrier Proteins; D004269:DNA, Bacterial; C429765:GPA1 protein, Arabidopsis; D044385:GTP-Binding Protein alpha Subunits; D044388:GTP-Binding Protein gamma Subunits; D047908:Intracellular Signaling Peptides and Proteins; C478976:PRN protein, Arabidopsis; C036483:T-DNA; C478978:pirin3 protein, Arabidopsis; D000040:Abscisic Acid