Molecular basis of CONSTANS oligomerization in FLOWERING LOCUS T activation  

作　　者：Xiaolin Zeng Xinchen Lv Rui Liu Hang He Shiqi Liang Lixian Chen Fan Zhang Liu Chen Yuehui He Jiamu Du 

机构地区：[1]Peking-Tsinghua Center for Life Sciences,School of Advanced Agricultural Sciences,Peking University,Beijing,100871 China [2]National Key Laboratory of Plant Molecular Genetics&Shanghai Center for Plant Stress Biology,Chinese Academy of Sciences Center for Excellence in Molecular Plant Sciences,Shanghai,201602 China [3]Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes,Institute of Plant and Food Science,Department of Biology,School of Life Sciences,Southern University of Science and Technology,Shenzhen,518055 China [4]Peking University Institute of Advanced Agricultural Sciences,Weifang,261000 China

出　　处：《Journal of Integrative Plant Biology》2022年第3期731-740,共10页植物学报（英文版）

基　　金：supported by the Shenzhen Science and Technology Program(JCYJ20200109110403829 and KQTD20190929173906742 to Jiamu Du);the National Natural Science Foundation of China(31721001 to Yuehui He);the National Key Research and Development Program of China(2017YFA0503803 to Yuehui He);the Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes(2019KSYS006 to Jiamu Du)。

摘　　要：The transcription factor CONSTANS(CO)integrates day-length information to induce the expression of florigen FLOWERING LOCUS T(FT)in Arabidopsis.We recently reported that the C-terminal CCT domain of CO forms a complex with NUCLEAR FACTOR-YB/YC to recognize multiple cis-elements in the FT promoter,and the N-terminal tandem B-box domains form a homomultimeric assembly.However,the mechanism and biological function of CO multimerization remained unclear.Here,we report that CO takes on a head-to-tail oligomeric configuration via its B-boxes to mediate FT activation in long days.The crystal structure of B-boxesCOreveals a closely connected tandem B-box fold forming a continuous head-to-tail assembly through unique CDHH zinc fingers.Mutating the key residues involved in CO oligomerization resulted in a non-functional CO,as evidenced by the inability to rescue co mutants.By contrast,a transgene encoding a human p53-derived tetrameric peptide in place of the B-boxesCOrescued co mutant,emphasizing the essential role of BboxesCO-mediated oligomerization.Furthermore,we found that the four TGTG-bearing cis-elements in FT proximal promoter are required for FT activation in long days.Our results suggest that CO forms a multimer to bind to the four TGTG motifs in the FT promoter to mediate FT activation.

关 键 词：B-box domain CONSTANS crystal structure FLOWERING LOCUS T PHOTOPERIOD 

分 类 号：Q943[生物学—植物学]