| Structural highlights
Function
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.[1] [2] [3]
Publication Abstract from PubMed
High-throughput sequencing of hematologic malignancies and other cancers has revealed recurrent mis-sense mutations of genes encoding pre-mRNA splicing factors. The essential splicing factor U2AF2 recognizes a polypyrimidine-tract splice-site signal and initiates spliceosome assembly. Here, we investigate representative, acquired U2AF2 mutations, namely N196K or G301D amino acid substitutions associated with leukemia or solid tumors, respectively. We determined crystal structures of the wild-type (WT) compared with N196K- or G301D-substituted U2AF2 proteins, each bound to a prototypical AdML polypyrimidine tract, at 1.5, 1.4, or 1.7 A resolutions. The N196K residue appears to stabilize the open conformation of U2AF2 with an inter-RNA recognition motif hydrogen bond, in agreement with an increased apparent RNA-binding affinity of the N196K-substituted protein. The G301D residue remains in a similar position as the WT residue, where unfavorable proximity to the RNA phosphodiester could explain the decreased RNA-binding affinity of the G301D-substituted protein. We found that expression of the G301D-substituted U2AF2 protein reduces splicing of a minigene transcript carrying prototypical splice sites. We further show that expression of either N196K- or G301D-substituted U2AF2 can subtly alter splicing of representative endogenous transcripts, despite the presence of endogenous, WT U2AF2 such as would be present in cancer cells. Altogether, our results demonstrate that acquired U2AF2 mutations such as N196K and G301D are capable of dysregulating gene expression for neoplastic transformation.
Representative cancer-associated U2AF2 mutations alter RNA interactions and splicing.,Maji D, Glasser E, Henderson S, Galardi J, Pulvino MJ, Jenkins JL, Kielkopf CL J Biol Chem. 2020 Dec 11;295(50):17148-17157. doi: 10.1074/jbc.RA120.015339. Epub , 2020 Oct 5. PMID:33020180[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ 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
- ↑ Maji D, Glasser E, Henderson S, Galardi J, Pulvino MJ, Jenkins JL, Kielkopf CL. Representative cancer-associated U2AF2 mutations alter RNA interactions and splicing. J Biol Chem. 2020 Dec 11;295(50):17148-17157. PMID:33020180 doi:10.1074/jbc.RA120.015339
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