Feedback Regulation of DYT1 by Interactions with Downstream bHLH Factors Promotes DYT1 Nuclear Localization and Anther Development.
Transcriptional regulation is one of the most important mechanisms controlling development and cellular functions in plants and animals. The Arabidopsis thaliana bHLH transcription factor (TF) DYSFUNCTIONL TAPETUM1 (DYT1) is required for normal male fertility and anther development and activates the expression of the bHLH010/bHLH089/bHLH091 genes. Here, we showed that DYT1 is localized to both the cytoplasm and nucleus at anther stage 5 but specifically to the nucleus at anther stage 6 and onward. The bHLH010/bHLH089/bHLH091 proteins have strong nuclear localization signals, interact with DYT1, and facilitate the nuclear localization of DYT1. We further found that the conserved C-terminal BIF domain of DYT1 is required for its dimerization, nuclear localization, transcriptional activation activity, and function in anther development. Interestingly, when the BIF domain of DYT1 was replaced with that of bHLH010, the DYT1(N)-bHLH010(BIF) chimeric protein shows nuclear-preferential localization at anther stage 5 but could not fully rescue the dyt1-3 phenotype, suggesting that the normal spatio-temporal subcellular localization of DYT1 is important for DYT1 function and/or that the BIF domains from different bHLH members might be functionally distinct. Our results support an important positive feedback regulatory mechanism whereby downstream TFs increase the function of an upstream TF by enhancing its nucleus localization through the BIF domain.
State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering and Institute of Biodiversity Sciences, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200438, China.
Jie
J
Cui
State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering and Institute of Biodiversity Sciences, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200438, China.
Chenjiang
C
You
State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering and Institute of Biodiversity Sciences, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200438, China.
Engao
E
Zhu
State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China.
Qiang
Q
Huang
State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering and Institute of Biodiversity Sciences, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200438, China Center for Evolutionary Biology, Institutes of Biomedical Sciences, Fudan University, Shanghai 200438, China fangchang@fudan.edu.cn hongma@fudan.edu.cn.
Hong
0000-0001-8717-4422
H
Ma
State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering and Institute of Biodiversity Sciences, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200438, China fangchang@fudan.edu.cn hongma@fudan.edu.cn.
Fang
F
Chang
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D004422:Dystonia Musculorum Deformans / Q000235:genetics / Q000378:metabolism*; D035264:Flowers / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D011485:Protein Binding / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D014157:Transcription Factors; C000608378:bHLH010 protein, Arabidopsis