TY - JOUR
T1 - Conformational landscape of multidomain SMAD proteins
AU - Gomes, Tiago
AU - Martin-Malpartida, Pau
AU - Ruiz, Lidia
AU - Aragón, Eric
AU - Cordeiro, Tiago N.
AU - Macias, Maria J.
N1 - Funding Information:
TNC is a recipient of Stimulus of Scientific Employment, Individual Support from Fundação para a Ciência e a Tecnologia, Ministério da Ciência, Tecnologia e Ensino Superior, CEECIND/01443/2017 and M.J.M is an ICREA Programme Investigator.
Funding Information:
We thank the ESRF group for the help and access to the synchrotron Bio-SAXS BM29 beamline, and the Mass Spectrometry and Protein Expression Core Facilities (IRB Barcelona) for help and reagents. We also thank Dr. B. Brutscher (Institut de Biologie Structurale, Biomolecular NMR Spectroscopy Group, Grenoble, France) for the help with the acquisition of the NMR data at 850 MHz; A. Vea and C. Torner for support with protein purification; Dr. P. Bernard? for the support and suggestions on the methodology; and Dr. J. Massagu? for insightful discussions. Access to Bio-SAXS BM29 ESRF was part of the MX-1941 BAG proposal, access to ALBA synchrotron was through the BAG proposal 2018092972. This work has been financed through the Spanish MINECO program (BFU2014-53787-P and BFU2017-82675-P, M.J.M); the IRB Barcelona; The BBVA Foundation; the Horizon 2020 Programme; the iNEXT program (grant SMAD4 MH2 domain PID:7192, the FCT ? Funda??o para a Ci?ncia e a Tecnologia, I.P. Project MOSTMICRO-ITQB with references UIDB/04612/2020 and UIDP/04612/2020 (to ITQB-NOVA); FEDER Funds through COMPETE 2020 (0145-FEDER-007660). We gratefully acknowledge institutional funding from the CERCA Programme of the Catalan Government and from the Spanish Ministry of Economy, Industry and Competitiveness (MINECO) through the Centres of Excellence Severo Ochoa award. TNC is a recipient of Stimulus of Scientific Employment, Individual Support from Funda??o para a Ci?ncia e a Tecnologia, Minist?rio da Ci?ncia, Tecnologia e Ensino Superior, CEECIND/01443/2017 and M.J.M is an ICREA Programme Investigator.
Funding Information:
This work has been financed through the Spanish MINECO program (BFU2014-53787-P and BFU2017-82675-P, M.J.M); the IRB Barcelona; The BBVA Foundation; the Horizon 2020 Programme; the iNEXT program (grant SMAD4 MH2 domain PID:7192, the FCT – Fundação para a Ciência e a Tecnologia, I.P., Project MOSTMICRO-ITQB with references UIDB/04612/2020 and UIDP/04612/2020 (to ITQB-NOVA); FEDER Funds through COMPETE 2020 (0145-FEDER-007660). We gratefully acknowledge institutional funding from the CERCA Programme of the Catalan Government and from the Spanish Ministry of Economy, Industry and Competitiveness (MINECO) through the Centres of Excellence Severo Ochoa award.
Publisher Copyright:
© 2021 The Author(s)
PY - 2021/1
Y1 - 2021/1
N2 - SMAD transcription factors, the main effectors of the TGFβ (transforming growth factor β) network, have a mixed architecture of globular domains and flexible linkers. Such a complicated architecture precluded the description of their full-length (FL) structure for many years. In this study, we unravel the structures of SMAD4 and SMAD2 proteins through an integrative approach combining Small-angle X-ray scattering, Nuclear Magnetic Resonance spectroscopy, X-ray, and computational modeling. We show that both proteins populate ensembles of conformations, with the globular domains tethered by disordered and flexible linkers, which defines a new dimension of regulation. The flexibility of the linkers facilitates DNA and protein binding and modulates the protein structure. Yet, SMAD4FL is monomeric, whereas SMAD2FL is in different monomer–dimer-trimer states, driven by interactions of the MH2 domains. Dimers are present regardless of the SMAD2FL activation state and concentration. Finally, we propose that SMAD2FL dimers are key building blocks for the quaternary structures of SMAD complexes.
AB - SMAD transcription factors, the main effectors of the TGFβ (transforming growth factor β) network, have a mixed architecture of globular domains and flexible linkers. Such a complicated architecture precluded the description of their full-length (FL) structure for many years. In this study, we unravel the structures of SMAD4 and SMAD2 proteins through an integrative approach combining Small-angle X-ray scattering, Nuclear Magnetic Resonance spectroscopy, X-ray, and computational modeling. We show that both proteins populate ensembles of conformations, with the globular domains tethered by disordered and flexible linkers, which defines a new dimension of regulation. The flexibility of the linkers facilitates DNA and protein binding and modulates the protein structure. Yet, SMAD4FL is monomeric, whereas SMAD2FL is in different monomer–dimer-trimer states, driven by interactions of the MH2 domains. Dimers are present regardless of the SMAD2FL activation state and concentration. Finally, we propose that SMAD2FL dimers are key building blocks for the quaternary structures of SMAD complexes.
KW - Intrinsically disordered regions
KW - Multi-domain proteins
KW - SMAD
KW - TGFβ signaling
KW - Transcription factor
UR - http://www.scopus.com/inward/record.url?scp=85115446068&partnerID=8YFLogxK
U2 - 10.1016/j.csbj.2021.09.009
DO - 10.1016/j.csbj.2021.09.009
M3 - Article
AN - SCOPUS:85115446068
SN - 2001-0370
VL - 19
SP - 5210
EP - 5224
JO - Computational and Structural Biotechnology Journal
JF - Computational and Structural Biotechnology Journal
ER -