2mb0 | pdb_00002mb0
Solution structure of hnRNP G RRM in complex with the RNA 5'-AUCAAA-3'
Structural highlights
Function[RBMX_HUMAN] RNA-binding protein that plays several role in the regulation of pre- and post-transcriptional processes. Implicated in tissue-specific regulation of gene transcription and alternative splicing of several pre-mRNAs. Binds to and stimulates transcription from the tumor suppressor TXNIP gene promoter; may thus be involved in tumor suppression. When associated with SAFB, binds to and stimulates transcription from the SREBF1 promoter. Associates with nascent mRNAs transcribed by RNA polymerase II. Component of the supraspliceosome complex that regulates pre-mRNA alternative splice site selection. Can either activate or suppress exon inclusion; acts additively with TRA2B to promote exon 7 inclusion of the survival motor neuron SMN2. Represses the splicing of MAPT/Tau exon 10. Binds preferentially to single-stranded 5'-CC[A/C]-rich RNA sequence motifs localized in a single-stranded conformation; probably binds RNA as a homodimer. Binds non-specifically to pre-mRNAs. Plays also a role in the cytoplasmic TNFR1 trafficking pathways; promotes both the IL-1-beta-mediated inducible proteolytic cleavage of TNFR1 ectodomains and the release of TNFR1 exosome-like vesicles to the extracellular compartment.[1] [2] [3] [4] [5] [6] [7] Publication Abstract from PubMedRegulation of SMN2 exon 7 splicing is crucial for the production of active SMN protein and the survival of Spinal Muscular Atrophy (SMA) patients. One of the most efficient activators of exon 7 inclusion is hnRNP G, which is recruited to the exon by Tra2-beta1. We report that in addition to the C-terminal region of hnRNP G, the RNA Recognition Motif (RRM) and the middle part of the protein containing the Arg-Gly-Gly (RGG) box are important for this function. To better understand the mode of action of hnRNP G in this context we determined the structure of its RRM bound to an SMN2 derived RNA. The RRM interacts with a 5'-AAN-3' motif and specifically recognizes the two consecutive adenines. By testing the effect of mutations in hnRNP G RRM and in its putative binding sites on the splicing of SMN2 exon 7, we show that it specifically binds to exon 7. This interaction is required for hnRNP G splicing activity and we propose its recruitment to a polyA tract located upstream of the Tra2-beta1 binding site. Finally, our data suggest that hnRNP G plays a major role in the recruitment of the Tra2-beta1/hnRNP G/SRSF9 trimeric complex to SMN2 exon 7. Characterization of the RNA recognition mode of hnRNP G extends its role in SMN2 splicing regulation.,Moursy A, Allain FH, Clery A Nucleic Acids Res. 2014 Apr 4. PMID:24692659[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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