title: Functional variations modulating PRKCA expression and alternative splicing predispose to multiple sclerosis.
abstract: The protein kinase C alpha (PRKCA) gene, encoding a Th17-cell-selective kinase, was repeatedly associated with multiple sclerosis (MS), but the underlying pathogenic mechanism remains unknown. We replicated the association in Italians (409 cases, 723 controls), identifying a protective signal in the PRKCA promoter (P = 0.033), and a risk haplotype in intron 3 (P = 7.7 × 10(-4); meta-analysis with previously published data: P = 4.01 × 10(-8)). Expression experiments demonstrated that the protective signal is associated with alleles conferring higher PRKCA expression levels, well fitting our observation that MS patients have significantly lower PRKCA mRNA levels in blood. The risk haplotype was shown to be driven by a GGTG ins/del polymorphism influencing the heterogeneous nuclear ribonucleoprotein H-dependent inclusion/skipping of a PRKCA alternative exon 3*. Indeed, exon 3* can be present in two different versions in PRKCA mRNAs (out-of-frame 61 bp or in-frame 66 bp long), and is preferentially included in transcripts generated through a premature polyadenylation event. The GGTG insertion downregulates 3* inclusion and shifts splicing towards the 66 bp isoform. Both events reduce the nonsense-mediated mRNA-decay-induced degradation of exon 3*-containing mRNAs. Since we demonstrated that the protein isoform produced through premature polyadenylation aberrantly localizes to the plasma membrane and/or in cytoplasmic clusters, dysregulated PRKCA 3* inclusion may represent an additional mechanism relevant to MS susceptibility.
authors: Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Milano 20133, Italy.
authors: Elvezia M
authors: EM
authors: Paraboschi
authors: Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Milano 20133, Italy.
authors: Valeria
authors: V
authors: Rimoldi
authors: Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Milano 20133, Italy.
authors: Giulia
authors: G
authors: Soldà
authors: Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Milano 20133, Italy.
authors: Tommaso
authors: T
authors: Tabaglio
authors: Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Milano 20133, Italy.
authors: Claudia
authors: C
authors: Dall'Osso
authors: Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Milano 20133, Italy.
authors: Elena
authors: E
authors: Saba
authors: Center Hemostasis and Thrombosis, Hematology Section, Department of Medical Sciences, University of Ferrara, Ferrara 44124, Italy.
authors: Marco
authors: M
authors: Vigliano
authors: Unit of Neurological Genetics, Department of Neurological and Movement Sciences, University of Verona, Verona 37134, Italy.
authors: Alessandro
authors: A
authors: Salviati
authors: SCDU Neurology, AOU "Maggiore della Carità", Novara 28100, Italy Interdisciplinary Research Center of Autoimmune Diseases IRCAD and.
authors: Maurizio
authors: M
authors: Leone
authors: Department of Neurosciences, University Hospital, Verona 37134, Italy.
authors: Maria D
authors: MD
authors: Benedetti
authors: Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Milano 20133, Italy.
authors: Diego
authors: D
authors: Fornasari
authors: Institute for Molecular Medicine Finland FIMM, University of Helsinki, Helsinki, Finland.
authors: Janna
authors: J
authors: Saarela
authors: Department of Neurology, Program in Translational NeuroPsychiatric Genomics, Institute for the Neurosciences, Brigham & Women's Hospital, Boston, MA, USA Division of Genetics, Department of Medicine, Brigham & Women's Hospital and Harvard Medical School, Boston, MA, USA and Broad Institute of Harvard and MIT, Cambridge, MA, USA.
authors: Philip L
authors: PL
authors: De Jager
authors: Department of Neurology, Program in Translational NeuroPsychiatric Genomics, Institute for the Neurosciences, Brigham & Women's Hospital, Boston, MA, USA Division of Genetics, Department of Medicine, Brigham & Women's Hospital and Harvard Medical School, Boston, MA, USA and Broad Institute of Harvard and MIT, Cambridge, MA, USA.
authors: Nikolaos A
authors: NA
authors: Patsopoulos
authors: Interdisciplinary Research Center of Autoimmune Diseases IRCAD and Department of Health Sciences, University of Eastern Piedmont, Novara 28100, Italy.
authors: Sandra
authors: S
authors: D'Alfonso
authors: Center Hemostasis and Thrombosis, Hematology Section, Department of Medical Sciences, University of Ferrara, Ferrara 44124, Italy.
authors: Donato
authors: D
authors: Gemmati
authors: Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Milano 20133, Italy.
authors: Stefano
authors: S
authors: Duga
authors: Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Milano 20133, Italy rosanna.asselta@unimi.it rosanna.asselta@gmail.com.
authors: Rosanna
authors: R
authors: Asselta
mesh_terms: D000483:Alleles; D017398:Alternative Splicing; D002460:Cell Line; D002886:Chromosomes, Human, Pair 17 / Q000737:chemistry; D005091:Exons; D005260:Female; D056426:Genetic Loci; D020022:Genetic Predisposition to Disease; D006801:Humans; D054643:INDEL Mutation; D007438:Introns; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D011401:Promoter Regions, Genetic; D051571:Protein Kinase C-alpha / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D020871:RNA Stability; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D012333:RNA, Messenger; C496628:PRKCA protein, human; D051571:Protein Kinase C-alpha