| Structural highlights
Function
[SF01_HUMAN] Necessary for the ATP-dependent first step of spliceosome assembly. Binds to the intron branch point sequence (BPS) 5'-UACUAAC-3' of the pre-mRNA. May act as transcription repressor.[1] [2] [3] [U2AF2_HUMAN] Necessary for the splicing of pre-mRNA. Induces cardiac troponin-T (TNNT2) pre-mRNA exon inclusion in muscle. Regulates the TNNT2 exon 5 inclusion through competition with MBNL1. Binds preferentially to a single-stranded structure within the polypyrimidine tract of TNNT2 intron 4 during spliceosome assembly. Required for the export of mRNA out of the nucleus, even if the mRNA is encoded by an intron-less gene. Represses the splicing of MAPT/Tau exon 10.[4] [5] [6]
Publication Abstract from PubMed
Recognition of the 3'-splice site is a key step in pre-mRNA splicing and accomplished by a dynamic complex comprising splicing factor 1 (SF1) and the U2 snRNP auxiliary factor 65-kDa subunit (U2AF65). Both proteins mediate protein-protein and protein-RNA interactions for cooperative RNA-binding during spliceosome assembly. Here, we report the solution structure of a novel helix-hairpin domain in the N-terminal region of SF1 (SF1(NTD)). The nuclear magnetic resonance- and small-angle X-ray scattering-derived structure of a complex of the SF1(NTD) with the C-terminal U2AF homology motif domain of U2AF65 (U2AF65(UHM)) reveals that, in addition to the known U2AF65(UHM)-SF1 interaction, the helix-hairpin domain forms a secondary, hydrophobic interface with U2AF65(UHM), which locks the orientation of the two subunits. Mutational analysis shows that the helix hairpin is essential for cooperative formation of the ternary SF1-U2AF65-RNA complex. We further show that tandem serine phosphorylation of a conserved Ser80-Pro81-Ser82-Pro83 motif rigidifies a long unstructured linker in the SF1 helix hairpin. Phosphorylation does not significantly alter the overall conformations of SF1, SF1-U2AF65 or the SF1-U2AF65-RNA complexes, but slightly enhances RNA binding. Our results indicate that the helix-hairpin domain of SF1 is required for cooperative 3'-splice site recognition presumably by stabilizing a unique quaternary arrangement of the SF1-U2AF65-RNA complex.
Structure, phosphorylation and U2AF65 binding of the N-terminal domain of splicing factor 1 during 3'-splice site recognition.,Zhang Y, Madl T, Bagdiul I, Kern T, Kang HS, Zou P, Mausbacher N, Sieber SA, Kramer A, Sattler M Nucleic Acids Res. 2013 Jan 1;41(2):1343-1354. Epub 2012 Nov 21. PMID:23175611[7]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Arning S, Gruter P, Bilbe G, Kramer A. Mammalian splicing factor SF1 is encoded by variant cDNAs and binds to RNA. RNA. 1996 Aug;2(8):794-810. PMID:8752089
- ↑ Wang X, Bruderer S, Rafi Z, Xue J, Milburn PJ, Kramer A, Robinson PJ. Phosphorylation of splicing factor SF1 on Ser20 by cGMP-dependent protein kinase regulates spliceosome assembly. EMBO J. 1999 Aug 16;18(16):4549-59. PMID:10449420 doi:http://dx.doi.org/10.1093/emboj/18.16.4549
- ↑ Zhang D, Paley AJ, Childs G. The transcriptional repressor ZFM1 interacts with and modulates the ability of EWS to activate transcription. J Biol Chem. 1998 Jul 17;273(29):18086-91. PMID:9660765
- ↑ Wang J, Gao QS, Wang Y, Lafyatis R, Stamm S, Andreadis A. Tau exon 10, whose missplicing causes frontotemporal dementia, is regulated by an intricate interplay of cis elements and trans factors. J Neurochem. 2004 Mar;88(5):1078-90. PMID:15009664
- ↑ Warf MB, Diegel JV, von Hippel PH, Berglund JA. The protein factors MBNL1 and U2AF65 bind alternative RNA structures to regulate splicing. Proc Natl Acad Sci U S A. 2009 Jun 9;106(23):9203-8. doi:, 10.1073/pnas.0900342106. Epub 2009 May 26. PMID:19470458 doi:10.1073/pnas.0900342106
- ↑ Webby CJ, Wolf A, Gromak N, Dreger M, Kramer H, Kessler B, Nielsen ML, Schmitz C, Butler DS, Yates JR 3rd, Delahunty CM, Hahn P, Lengeling A, Mann M, Proudfoot NJ, Schofield CJ, Bottger A. Jmjd6 catalyses lysyl-hydroxylation of U2AF65, a protein associated with RNA splicing. Science. 2009 Jul 3;325(5936):90-3. PMID:19574390 doi:325/5936/90
- ↑ Zhang Y, Madl T, Bagdiul I, Kern T, Kang HS, Zou P, Mausbacher N, Sieber SA, Kramer A, Sattler M. Structure, phosphorylation and U2AF65 binding of the N-terminal domain of splicing factor 1 during 3'-splice site recognition. Nucleic Acids Res. 2013 Jan 1;41(2):1343-1354. Epub 2012 Nov 21. PMID:23175611 doi:http://dx.doi.org/10.1093/nar/gks1097
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