担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

CLV3 is a plant peptide hormone in which the proline residues are post-transcriptionally hydroxylated and glycosylated. CLV3 plays a key role in controlling the stem cell mass in the shoot meristem of Arabidopsis thaliana. In a previous report, we identified a dodecapeptide (MCLV3) from CLV3-overexpressing Arabidopsis calli; MCLV3 was the smallest functional peptide derived from the CLV3 precursor. Here, we designed a series of MCLV3 analogs in which proline residues were substituted with proline derivatives or N-substituted glycines (peptoids). Peptoid substitution at Pro9 decreased bioactivity without affecting specific binding to the CLV1-related protein in cauliflower membrane. These findings suggest that peptoid-substituted peptides would be lead compounds for developing potential agonists and antagonists of CLV3.

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

Stomata are composed of a pair of guard cells and a pore between them, and their density and positions are regulated by developmental and environmental signals. In a screen which we overexpressed many genes coding for putative secretory proteins one-by-one in Arabidopsis, we identified a gene named STOMAGEN, which increases stomatal density when overexpressed. The STOMAGEN gene encodes a small peptide with a putative secretory-signal sequence at its N-terminus and is expressed preferentially in mesophyll cells. This peptide belongs to the EPIDERMAL PATTERNING FACTOR (EPF) family of the cysteine-rich-peptides superfamily. The mature form was a 45-amino-acid peptide (stomagen) with three intra-molecular disulphide bonds. Stomagen treatment at very low concentrations, as low as 10 nM, increased stomatal density of wild-type Arabidopsis plants. We propose that stomagen is a mesophyll-to-epidermis signaling molecule that positively regulates stomatal density. We also suggest that stomagen increases stomatal density by competing with negative regulators EPF1 and EPF2 for the receptor-like protein TOO MANY MOUTHS.

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

The dodecapeptide MCLV3 is a functional peptide, derived from the CLV3 precursor protein, which is a candidate ligand of the CLV1/CLV2 receptor complex that restricts the stem cell population in the shoot apical meristem (SAM). MCLV3 can induce shoot and root meristem consumption, the typical phenotype of transgenic plants overexpressing CLV3. We investigated the bioactivities of a series of alanine-substituted MCLV3 and related peptides on the root growth of Arabidopsis. The structure-activity relationship (SAR) of MCLV3 had high similarity with that of tracheary element differentiation inhibitory factor (TDIF). We also evaluated the binding activities of the peptides by a competitive receptor binding assay using tritiated MCLV3 and the membrane fraction of a tobacco BY-2 cell line overexpressing the MCLV3 ectodomain. This dual assay, combining a biological and receptor binding assay for evaluating the activities of MCLV3-related peptides, uncovered the SAR of MCLV3, and indicated that the terminal residues play critical roles in exerting its activity and are important for specific binding to the receptor, CLV1.

担当区分：筆頭著者   記述言語：日本語  

シロイヌナズナのゲノム解読以降,植物の生産する生理活性ペプチド,すなわち植物ペプチドホルモンの研究が著しい進展を遂げている.筆者らのグループは, シロイヌナズナのカルスの凍結切片を直接MALDI-TOF MSで分析することで分泌型のペプチドホルモンを直接検出する手法について検討した.この手法を用いて,茎頂分裂組織で発現するCLV3遺伝子の転写産物のC末端付近の保存領域(CLEモチーフ)に由来する12残基の修飾ペプチド, MCLV3を同定した. MCLV3は非常に低い濃度で茎頂および根端の分裂組織の機能を阻害したことから, CLV3に由来する生理活性ペプチドであることが明らかになった.近年, CLV3と同様にC末端付近にCLEモチーフを有する分泌型タンパク質をコードした遺伝子が多数発見されており,このCLEモチーフに由来するペプチド (CLEペプチド)が注目を集めている.本総説では我々の研究とともに, CLEペプチドに関する最新の知見についても紹介する.

担当区分：筆頭著者   記述言語：日本語  

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

The Arabidopsis CLAVATA3 (CLV3) gene encodes a stem cell-specific protein presumed to be a precursor of a secreted peptide hormone. Matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry (TOF-MS) applied to in situ Arabidopsis tissues determined the structure of a modified 12-amino acid peptide (MCLV3), which was derived from a conserved motif in the CLV3 sequence. Synthetic MCLV3 induced shoot and root meristem consumption as cells differentiate into other organs; the typical phenotype of transgenic plants overexpressing CLV3. These results suggest that the functional peptide of CLV3 is MCLV3.

記述言語：日本語  

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

開催年月日： 2006年10月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2006年7月

記述言語：英語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2006年3月

記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2005年3月

記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2005年1月

記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2004年11月

記述言語：日本語   会議種別：ポスター発表