title: miR-634 is a Pol III-dependent intronic microRNA regulating alternative-polyadenylated isoforms of its host gene PRKCA.
abstract: The protein kinase C alpha (PRKCA) gene, coding for a Th17-cell-selective kinase, shows a complex splicing pattern, with at least 2 stable alternative transcripts characterized by an alternative upstream polyadenylation site. Polymorphisms in this gene were associated with several conditions, including multiple sclerosis, asthma, schizophrenia, and cancer. The presence of a microRNA (miRNA), i.e. miR-634, within intron 15 of the PRKCA gene, suggests the intriguing possibility that this miRNA might play a role in the susceptibility to these pathologies.
  
  
  
  Here, we characterized miR-634 expression profile and searched for its putative targets using a combination of RT-PCR and gene reporter assays.
  
  
  
  The quantitative analysis of PRKCA and miR-634 transcripts in a panel of human tissues and cell lines revealed discordant expression profiles, suggesting the presence of an independent miR-634 promoter and/or a possible direct role of miR-634 in modulating PRKCA expression. Functional studies demonstrated the existence of a miRNA-specific promoter, which was shown to be Pol-III-dependent. Furthermore, transfection experiments showed that miR-634 is able to target its host gene by specifically down-regulating the shorter alternative-polyadenylated isoforms.
  
  
  
  MiR-634 is a Pol III-dependent intronic miRNA, which could target its host gene through a "first-order" negative feedback.
  
  
  
  MiR-634 is one of the few characterized examples of Pol-III-dependent intronic miRNAs. Its independent transcription from the host gene suggests caution in using expression profiles of host genes as proxies for the expression of the corresponding intronic miRNAs.
authors.affiliation: Department of Biomedical Sciences, Humanitas University, Via Manzoni 113, 20089, Rozzano, Milan, Italy.
authors.forename: Elvezia Maria
authors.initials: EM
authors.lastname: Paraboschi
authors.affiliation: Department of Biomedical Sciences, Humanitas University, Via Manzoni 113, 20089, Rozzano, Milan, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Cardamone
authors.affiliation: Department of Biomedical Sciences, Humanitas University, Via Manzoni 113, 20089, Rozzano, Milan, Italy; Humanitas Clinical and Research Center, Via Manzoni 56, 20089, Rozzano, Milan, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Rimoldi
authors.affiliation: Department of Biomedical Sciences, Humanitas University, Via Manzoni 113, 20089, Rozzano, Milan, Italy; Humanitas Clinical and Research Center, Via Manzoni 56, 20089, Rozzano, Milan, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Duga
authors.affiliation: Department of Biomedical Sciences, Humanitas University, Via Manzoni 113, 20089, Rozzano, Milan, Italy; Humanitas Clinical and Research Center, Via Manzoni 56, 20089, Rozzano, Milan, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Soldà
authors.affiliation: Department of Biomedical Sciences, Humanitas University, Via Manzoni 113, 20089, Rozzano, Milan, Italy; Humanitas Clinical and Research Center, Via Manzoni 56, 20089, Rozzano, Milan, Italy. Electronic address: rosanna.asselta@hunimed.eu.
authors.forename: Rosanna
authors.initials: R
authors.lastname: Asselta
mesh_terms: D002460:Cell Line; D045744:Cell Line, Tumor; D015536:Down-Regulation / Q000235:genetics; D005786:Gene Expression Regulation / Q000235:genetics; D017930:Genes, Reporter / Q000235:genetics; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D007438:Introns / Q000235:genetics*; D035683:MicroRNAs / Q000235:genetics*; D026723:Polyadenylation / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D020033:Protein Isoforms / Q000235:genetics*; D051571:Protein Kinase C-alpha / Q000235:genetics*; D012320:RNA Polymerase III / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics; D059467:Transcriptome / Q000235:genetics
chemical_list: C000599270:MIRN-634 microRNA, human; D035683:MicroRNAs; D020033:Protein Isoforms; C496628:PRKCA protein, human; D051571:Protein Kinase C-alpha; D012320:RNA Polymerase III
keywords: Multiple sclerosis; PRKCA; Promoter; Target gene; miR-634