| Structural highlights
Function
[SMAD2_HUMAN] Receptor-regulated SMAD (R-SMAD) that is an intracellular signal transducer and transcriptional modulator activated by TGF-beta (transforming growth factor) and activin type 1 receptor kinases. Binds the TRE element in the promoter region of many genes that are regulated by TGF-beta and, on formation of the SMAD2/SMAD4 complex, activates transcription. May act as a tumor suppressor in colorectal carcinoma. Positively regulates PDPK1 kinase activity by stimulating its dissociation from the 14-3-3 protein YWHAQ which acts as a negative regulator.[1] [2] [3] [4] [5]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Ligand-induced phosphorylation of the receptor-regulated Smads (R-Smads) is essential in the receptor Ser/Thr kinase-mediated TGF-beta signaling. The crystal structure of a phosphorylated Smad2, at 1.8 A resolution, reveals the formation of a homotrimer mediated by the C-terminal phosphoserine (pSer) residues. The pSer binding surface on the MH2 domain, frequently targeted for inactivation in cancers, is highly conserved among the Co- and R-Smads. This finding, together with mutagenesis data, pinpoints a functional interface between Smad2 and Smad4. In addition, the pSer binding surface on the MH2 domain coincides with the surface on R-Smads that is required for docking interactions with the serine-phosphorylated receptor kinases. These observations define a bifunctional role for the MH2 domain as a pSer-X-pSer binding module in receptor Ser/Thr kinase signaling pathways.
Crystal structure of a phosphorylated Smad2. Recognition of phosphoserine by the MH2 domain and insights on Smad function in TGF-beta signaling.,Wu JW, Hu M, Chai J, Seoane J, Huse M, Li C, Rigotti DJ, Kyin S, Muir TW, Fairman R, Massague J, Shi Y Mol Cell. 2001 Dec;8(6):1277-89. PMID:11779503[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Lebrun JJ, Takabe K, Chen Y, Vale W. Roles of pathway-specific and inhibitory Smads in activin receptor signaling. Mol Endocrinol. 1999 Jan;13(1):15-23. PMID:9892009
- ↑ Lin X, Duan X, Liang YY, Su Y, Wrighton KH, Long J, Hu M, Davis CM, Wang J, Brunicardi FC, Shi Y, Chen YG, Meng A, Feng XH. PPM1A functions as a Smad phosphatase to terminate TGFbeta signaling. Cell. 2006 Jun 2;125(5):915-28. PMID:16751101 doi:10.1016/j.cell.2006.03.044
- ↑ Seong HA, Jung H, Kim KT, Ha H. 3-Phosphoinositide-dependent PDK1 negatively regulates transforming growth factor-beta-induced signaling in a kinase-dependent manner through physical interaction with Smad proteins. J Biol Chem. 2007 Apr 20;282(16):12272-89. Epub 2007 Feb 27. PMID:17327236 doi:10.1074/jbc.M609279200
- ↑ Inoue Y, Itoh Y, Abe K, Okamoto T, Daitoku H, Fukamizu A, Onozaki K, Hayashi H. Smad3 is acetylated by p300/CBP to regulate its transactivation activity. Oncogene. 2007 Jan 25;26(4):500-8. Epub 2006 Jul 24. PMID:16862174 doi:10.1038/sj.onc.1209826
- ↑ Dai F, Lin X, Chang C, Feng XH. Nuclear export of Smad2 and Smad3 by RanBP3 facilitates termination of TGF-beta signaling. Dev Cell. 2009 Mar;16(3):345-57. doi: 10.1016/j.devcel.2009.01.022. PMID:19289081 doi:10.1016/j.devcel.2009.01.022
- ↑ Wu JW, Hu M, Chai J, Seoane J, Huse M, Li C, Rigotti DJ, Kyin S, Muir TW, Fairman R, Massague J, Shi Y. Crystal structure of a phosphorylated Smad2. Recognition of phosphoserine by the MH2 domain and insights on Smad function in TGF-beta signaling. Mol Cell. 2001 Dec;8(6):1277-89. PMID:11779503
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