AtSWI3B, an Arabidopsis homolog of SWI3, a core subunit of yeast Swi/Snf chromatin remodeling complex, interacts with FCA, a regulator of flowering time.
ATP-dependent nucleosome remodeling plays a central role in the regulation of access to chromatin DNA. Swi/Snf remodeling complexes characterized in yeast, Drosophila and mammals all contain a conserved set of core subunits composed of homologs of yeast SNF2-type DNA-dependent ATPase, SNF5 and SWI3 proteins. So far, no complete Swi/Snf-type complex has been characterized in plants. Arabidopsis contains a single SNF5-type gene, BSH, which has been shown to complement the yeast snf5 mutation. Here we describe the characterization of AtSWI3B, the smallest of the four Arabidopsis homologs of SWI3. The gene encoding AtSWI3B is expressed ubiquitously in the plant. AtSWI3B is localized to nuclei and is associated mostly with the chromatin and soluble protein fractions. When expressed in Saccharomyces cerevisiae, the cDNA encoding AtSWI3B partially complements the swi3 mutant phenotype. However, like BSH, AtSWI3B is unable to activate transcription in yeast when tethered to DNA. The analysis by yeast two-hybrid indicates that AtSWI3B is capable of forming homodimers and interacts with BSH as well as with two other members of the Arabidopsis SWI3 family: AtSWI3A and AtSWI3C. The results of phage display screen using recombinant protein, confirmed by direct yeast two-hybrid analyses, indicate that AtSWI3B interacts with FCA, a regulator of flowering time in Arabidopsis. This interaction is through the C-terminal region of FCA, located outside the conserved RNA- and protein-binding domains of this protein.
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw University, Pawińskiego 5A, 02-106 Warsaw, Poland.
Tomasz J
TJ
Sarnowski
Szymon
S
Swiezewski
Katarzyna
K
Pawlikowska
Szymon
S
Kaczanowski
Andrzej
A
Jerzmanowski
D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism*; D002467:Cell Nucleus / Q000737:chemistry; D002843:Chromatin / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D006801:Humans; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics*; D010802:Phylogeny; D010940:Plant Proteins; D021122:Protein Subunits; D016601:RNA-Binding Proteins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism*; D000071796:SMARCB1 Protein; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation
C463463:ATSWI3B protein, Arabidopsis; D029681:Arabidopsis Proteins; C120398:BSH protein, Arabidopsis; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; C106535:Flowering time control protein FCA, Arabidopsis; D005656:Fungal Proteins; D046911:Macromolecular Substances; D009687:Nuclear Proteins; D010940:Plant Proteins; D021122:Protein Subunits; D016601:RNA-Binding Proteins; D000071796:SMARCB1 Protein; C513266:SMARCB1 protein, human; C072981:SWI3 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D014157:Transcription Factors