Dual functions of the KNOTTED1 homeodomain: sequence-specific DNA binding and regulation of cell-to-cell transport.
Homeodomain proteins are well-characterized developmental regulators that control expression of target genes through sequence-specific DNA binding. The homeodomain forms a trihelical structure, with the third helix conferring specific interactions with the DNA major groove. A specific class of plant homeodomain proteins, called KNOX [KNOTTED1 (KN1)-like homeobox], also has the ability to signal between cells by directly trafficking through intercellular channels called plasmodesmata. Trafficking is mediated by a signal that is also contained within the homeodomain. Movement protein binding protein 2C was identified as a protein that interacts with the KN1 homeodomain and regulates the cell-to-cell trafficking of KN1 by sequestering the protein on microtubules. Therefore, KN1 has multiple potential cellular addresses, each of which is conferred by its homeodomain.
Plant Gene Expression Center, 800 Buchanan Street, Albany, CA 94710, USA.
Nathalie
N
Bolduc
Sarah
S
Hake
David
D
Jackson
D002450:Cell Communication; D018744:DNA, Plant / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism; D018398:Homeodomain Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D011198:Solanum tuberosum / Q000201:enzymology; D014026:Nicotiana / Q000201:enzymology; D014158:Transcription, Genetic
D018744:DNA, Plant; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; C095848:Kn1 protein, plant; D010940:Plant Proteins