title: Insight into the role of alternative splicing within the RBM10v1 exon 10 tandem donor site.
abstract: BACKGROUND
  RBM10 is an RNA binding protein involved in the regulation of transcription, alternative splicing and message stabilization. Mutations in RBM10, which maps to the X chromosome, are associated with TARP syndrome, lung and pancreatic cancers. Two predominant isoforms of RBM10 exist, RBM10v1 and RBM10v2. Both variants have alternate isoforms that differ by one valine residue, at amino acid 354 (RBM10v1) or 277 (RBM10v2). It was recently observed that a novel point mutation at amino acid 354 of RBM10v1, replacing valine with glutamic acid, correlated with preferential expression of an exon 11 inclusion variant of the proliferation regulatory protein NUMB, which is upregulated in lung cancer.
  
  
  RESULTS
  We demonstrate, using the GLC20 male-derived small cell lung cancer cell line - confirmed to have only one X chromosome - that the two (+/-) valine isoforms of RBM10v1 and RBM10v2 result from alternative splicing. Protein modeling of the RNA Recognition Motif (RRM) within which the alteration occurs, shows that the presence of valine inhibits the formation of one of the two α-helices associated with RRM tertiary structure, whereas the absence of valine supports the α-helical configuration. We then show 2-fold elevated expression of the transcripts encoding the minus valine RBM10v1 isoform in GLC20 cells, compared to those encoding the plus valine isoform. This expression correlates with preferential expression of the lung cancer-associated NUMB exon 11 inclusion variant.
  
  
  CONCLUSIONS
  Our observations suggest that the ability of RBM10v1 to regulate alternative splicing depends, at least in part, on a structural alteration within the second RRM domain, which influences whether RBM10v1 functions to support or repress splicing. A model is presented.
authors.affiliation: Department of Biology, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON, P3E 2C6, Canada. sarah.tessier@live.ca.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Tessier
authors.affiliation: Biomolecular Sciences Program, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON, P3E 2C6, Canada. loiselle.julie@gmail.com.
authors.forename: Julie J
authors.initials: JJ
authors.lastname: Loiselle
authors.affiliation: Genetics Lab, Health Sciences North, 41 Ramsey Lake Road, Sudbury, ON, P3E 5 J1, Canada. amcbain@hsnsudbury.ca.
authors.forename: Anne
authors.initials: A
authors.lastname: McBain
authors.affiliation: Department of Biology, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON, P3E 2C6, Canada. butlerc@timiskaminghu.com.
authors.forename: Celine
authors.initials: C
authors.lastname: Pullen
authors.affiliation: AMRIC, Health Sciences North, 41 Ramsey Lake Road, Sudbury, ON, P3E 5 J1, Canada. bkoenderink@amric.ca.
authors.forename: Benjamin W
authors.initials: BW
authors.lastname: Koenderink
authors.affiliation: Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON, P3E 2C6, Canada. jroy@amric.ca.
authors.forename: Justin G
authors.initials: JG
authors.lastname: Roy
authors.affiliation: Department of Biology, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON, P3E 2C6, Canada. lsutherland@amric.ca.|Biomolecular Sciences Program, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON, P3E 2C6, Canada. lsutherland@amric.ca.|AMRIC, Health Sciences North, 41 Ramsey Lake Road, Sudbury, ON, P3E 5 J1, Canada. lsutherland@amric.ca.|Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON, P3E 2C6, Canada. lsutherland@amric.ca.|Division of Medical Sciences, Northern Ontario School of Medicine, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON, P3E 2C6, Canada. lsutherland@amric.ca.|Department of Medicine, Division of Medical Oncology, University of Ottawa, Ottawa, ON, Canada. lsutherland@amric.ca.
authors.forename: Leslie C
authors.initials: LC
authors.lastname: Sutherland
mesh_terms: D017398:Alternative Splicing; D045744:Cell Line, Tumor; D005091:Exons; D015972:Gene Expression Regulation, Neoplastic; D018698:Glutamic Acid / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism; D059372:Nucleotide Motifs; D017354:Point Mutation; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D055752:Small Cell Lung Carcinoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D014633:Valine / Q000235:genetics / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C113026:NUMB protein, human; D020033:Protein Isoforms; C512260:RBM10 protein, human; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D018698:Glutamic Acid; D014633:Valine