title: Identification of evolutionarily conserved amino acid residues in homeodomain of KNOX proteins for intercellular trafficking.
abstract: Maize knotted (KN1) homeodomain (HD) protein is a well-known mobile transcription factor crucial for stem cell maintenance. Recent studies have revealed that the trihelical HD of knotted1-like homeobox (KNOX) proteins is necessary and sufficient for selective cell-to-cell trafficking. Also, the efficient trafficking ability for HD is likely to be acquired during the evolution of early nonvascular land plants. Here, using the point-mutated HD of KN1 and shoot meristemless (STM) in the trichome rescue system, together with molecular structure modeling, we have found the evolutionarily conserved amino acid residues, such as arginine in helix α1 and leucine in helix α3, which are essential for intercellular trafficking. Our studies provided important clues for the 3-dimensional protein structure required for cell-to-cell movement of non-cell-autonomous transcription factors.
authors.affiliation: Division of Applied Life Science (BK21plus); Plant Molecular Biology & Biotechnology Research Center; Gyeongsang National University; Jinju, Korea.
authors.forename: Huan
authors.initials: H
authors.lastname: Chen
authors.affiliation: Cold Spring Harbor Laboratory; Cold Spring Harbor, NY USA.
authors.forename: David
authors.initials: D
authors.lastname: Jackson
authors.affiliation: Division of Applied Life Science (BK21plus); Plant Molecular Biology & Biotechnology Research Center; Gyeongsang National University; Jinju, Korea.
authors.forename: Jae-Yean
authors.initials: JY
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D017124:Conserved Sequence; D018398:Homeodomain Proteins / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism; D021381:Protein Transport; D003313:Zea mays / Q000737:chemistry* / Q000378:metabolism
chemical_list: D018398:Homeodomain Proteins; D010940:Plant Proteins
keywords: homeodomain; intercellular protein trafficking; non-cell-autonomous; plasmodesmata; transcription factor