title: Smad2 and Smad3 have differential sensitivity in relaying TGFβ signaling and inversely regulate early lineage specification.
abstract: The transforming growth factor beta (TGFβ) related signaling is one of the most important signaling pathways regulating early developmental events. Smad2 and Smad3 are structurally similar and it is mostly considered that they are equally important in mediating TGFβ signals. Here, we show that Smad3 is an insensitive TGFβ transducer as compared with Smad2. Smad3 preferentially localizes within the nucleus and is thus sequestered from membrane signaling. The ability of Smad3 in oligomerization with Smad4 upon agonist stimulation is also impaired given its unique linker region. Smad2 mediated TGFβ signaling plays a crucial role in epiblast development and patterning of three germ layers. However, signaling unrelated nuclear localized Smad3 is dispensable for TGFβ signaling-mediated epiblast specification, but important for early neural development, an event blocked by TGFβ/Smad2 signaling. Both Smad2 and Smad3 bind to the conserved Smads binding element (SBE), but they show nonoverlapped target gene binding specificity and differential transcriptional activity. We conclude that Smad2 and Smad3 possess differential sensitivities in relaying TGFβ signaling and have distinct roles in regulating early developmental events.
authors.affiliation: Shanghai Tenth People's Hospital, and Neuroregeneration Key Laboratory of Shanghai Universities, Tongji University School of Medicine, Shanghai 200092, China.|Tongji University Advanced Institute of Translational Medicine, Shanghai 200092, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Liu
authors.affiliation: Shanghai Tenth People's Hospital, and Neuroregeneration Key Laboratory of Shanghai Universities, Tongji University School of Medicine, Shanghai 200092, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Liu
authors.affiliation: Shanghai Tenth People's Hospital, and Neuroregeneration Key Laboratory of Shanghai Universities, Tongji University School of Medicine, Shanghai 200092, China.
authors.forename: Xudong
authors.initials: X
authors.lastname: Ren
authors.affiliation: Shanghai Tenth People's Hospital, and Neuroregeneration Key Laboratory of Shanghai Universities, Tongji University School of Medicine, Shanghai 200092, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Tian
authors.affiliation: Shanghai Tenth People's Hospital, and Neuroregeneration Key Laboratory of Shanghai Universities, Tongji University School of Medicine, Shanghai 200092, China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Shanghai Tenth People's Hospital, and Neuroregeneration Key Laboratory of Shanghai Universities, Tongji University School of Medicine, Shanghai 200092, China.
authors.forename: Xiangjie
authors.initials: X
authors.lastname: Xu
authors.affiliation: The School of Life Sciences and Technology, Tongji University, Shanghai 200092.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Du
authors.affiliation: The School of Life Sciences and Technology, Tongji University, Shanghai 200092.
authors.forename: Cizhong
authors.initials: C
authors.lastname: Jiang
authors.affiliation: Shanghai Tenth People's Hospital, and Neuroregeneration Key Laboratory of Shanghai Universities, Tongji University School of Medicine, Shanghai 200092, China.
authors.forename: Yujiang
authors.initials: Y
authors.lastname: Fang
authors.affiliation: Shanghai Tenth People's Hospital, and Neuroregeneration Key Laboratory of Shanghai Universities, Tongji University School of Medicine, Shanghai 200092, China.
authors.forename: Zhongliang
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Shanghai Tenth People's Hospital, and Neuroregeneration Key Laboratory of Shanghai Universities, Tongji University School of Medicine, Shanghai 200092, China.
authors.forename: Beibei
authors.initials: B
authors.lastname: Fan
authors.affiliation: Shanghai Tenth People's Hospital, and Neuroregeneration Key Laboratory of Shanghai Universities, Tongji University School of Medicine, Shanghai 200092, China.
authors.forename: Quanbin
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Anatomy and Neurobiology, the Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Jiangsu 226001, China.
authors.forename: Guohua
authors.initials: G
authors.lastname: Jin
authors.affiliation: State Key Laboratory of Proteomics, Genetic Laboratory of Development and Diseases, Institute of Biotechnology, Beijing 100071, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Yang
authors.affiliation: Shanghai Tenth People's Hospital, and Neuroregeneration Key Laboratory of Shanghai Universities, Tongji University School of Medicine, Shanghai 200092, China.|Tongji University Advanced Institute of Translational Medicine, Shanghai 200092, China.|The Collaborative Innovation Center for Brain Science, Tongji University, Shanghai 200092, China.
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Zhang
mesh_terms: D021581:Active Transport, Cell Nucleus; D000818:Animals; D001483:Base Sequence; D019521:Body Patterning; D063646:Carcinogenesis / Q000378:metabolism; D019070:Cell Lineage; D002467:Cell Nucleus / Q000378:metabolism; D017124:Conserved Sequence; D057809:HEK293 Cells; D000066449:Human Embryonic Stem Cells / Q000378:metabolism; D006801:Humans; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D011485:Protein Binding; D055503:Protein Multimerization; D020218:Response Elements; D015398:Signal Transduction; D051899:Smad2 Protein / Q000502:physiology*; D051900:Smad3 Protein / Q000502:physiology*; D013724:Teratoma / Q000378:metabolism / Q000473:pathology; D016212:Transforming Growth Factor beta / Q000502:physiology*
chemical_list: C497782:SMAD2 protein, human; C497790:SMAD3 protein, human; D051899:Smad2 Protein; D051900:Smad3 Protein; D016212:Transforming Growth Factor beta