AtHSBP functions in seed development and the motif is required for subcellular localization and interaction with AtHSFs.
In Arabidopsis thaliana, heat shock factor binding protein (AtHSBP) is a negative regulator of the heat shock response (HSR), and defective AtHSBP leads to seed abortion. We found that the wild-type and AtHSBP-knockout plants did not differ in ovule phenotypes at flower position 3, which indicates that the seed abortion occurs after fertilization and during embryogenesis. The conserved residues of the hydrophobic heptad repeat (HR) domains in AtHSBP were mutated and examined for their subcellular localization and interacting ability with heat shock factors (AtHSFs). The HR domains at the C terminus of AtHSBP are important for retaining AtHSBP in the cytoplasm under normal growth conditions and for interacting with AtHSFs, which negatively affects the DNA-binding capacity and transactivation activity of AtHSFs during the HSR.
Hsu
Shih-Feng
SF
Institute of Plant Biology and Department of Life Science, National Taiwan University, Taipei, Taiwan.
Jinn
Tsung-Luo
TL
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D035264:Flowers / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D055786:Gene Knockout Techniques; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D012639:Seeds / Q000196:embryology* / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D006360:Heat-Shock Proteins