title: Uterine leiomyoma-linked MED12 mutations disrupt mediator-associated CDK activity.
abstract: Somatic mutations in exon 2 of the RNA polymerase II transcriptional Mediator subunit MED12 occur at very high frequency (∼70%) in uterine leiomyomas. However, the influence of these mutations on Mediator function and the molecular basis for their tumorigenic potential remain unknown. To clarify the impact of these mutations, we used affinity-purification mass spectrometry to establish the global protein-protein interaction profiles for both wild-type and mutant MED12. We found that uterine leiomyoma-linked mutations in MED12 led to a highly specific decrease in its association with Cyclin C-CDK8/CDK19 and loss of Mediator-associated CDK activity. Mechanistically, this occurs through disruption of a MED12-Cyclin C binding interface that we also show is required for MED12-mediated stimulation of Cyclin C-dependent CDK8 kinase activity. These findings indicate that uterine leiomyoma-linked mutations in MED12 uncouple Cyclin C-CDK8/19 from core Mediator and further identify the MED12/Cyclin C interface as a prospective therapeutic target in CDK8-driven cancers.
authors.affiliation: Genome-Scale Biology Program and Department of Pathology, Haartman Institute, University of Helsinki, Biomedicum, P.O. Box 63 (Haartmaninkatu 8), Helsinki FIN-00014, Finland.
authors.forename: Mikko
authors.initials: M
authors.lastname: Turunen
authors.affiliation: Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, Mail Code 8257, STRF, San Antonio, TX 78229-3900, USA.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Spaeth
authors.affiliation: Institute of Biotechnology, University of Helsinki, Viikinkaari 1, P.O. Box 65, Helsinki FIN-00014, Finland.
authors.forename: Salla
authors.initials: S
authors.lastname: Keskitalo
authors.affiliation: Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, Mail Code 8257, STRF, San Antonio, TX 78229-3900, USA.
authors.forename: Min Ju
authors.initials: MJ
authors.lastname: Park
authors.affiliation: Genome-Scale Biology Program and Department of Pathology, Haartman Institute, University of Helsinki, Biomedicum, P.O. Box 63 (Haartmaninkatu 8), Helsinki FIN-00014, Finland; Department of Computer Science, University of Helsinki, P.O. Box 68, Helsinki FIN-00014, Finland.
authors.forename: Teemu
authors.initials: T
authors.lastname: Kivioja
authors.affiliation: Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, Mail Code 8257, STRF, San Antonio, TX 78229-3900, USA.
authors.forename: Alison D
authors.initials: AD
authors.lastname: Clark
authors.affiliation: Genome-Scale Biology Program and Department of Medical Genetics, Haartman Institute, University of Helsinki, Biomedicum, P.O. Box 63 (Haartmaninkatu 8), Helsinki FIN-00014, Finland.
authors.forename: Netta
authors.initials: N
authors.lastname: Mäkinen
authors.affiliation: Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, Mail Code 8257, STRF, San Antonio, TX 78229-3900, USA.
authors.forename: Fangjian
authors.initials: F
authors.lastname: Gao
authors.affiliation: Genome-Scale Biology Program and Department of Pathology, Haartman Institute, University of Helsinki, Biomedicum, P.O. Box 63 (Haartmaninkatu 8), Helsinki FIN-00014, Finland.
authors.forename: Kimmo
authors.initials: K
authors.lastname: Palin
authors.affiliation: Institute of Biotechnology, University of Helsinki, Viikinkaari 1, P.O. Box 65, Helsinki FIN-00014, Finland.
authors.forename: Helka
authors.initials: H
authors.lastname: Nurkkala
authors.affiliation: Genome-Scale Biology Program and Department of Pathology, Haartman Institute, University of Helsinki, Biomedicum, P.O. Box 63 (Haartmaninkatu 8), Helsinki FIN-00014, Finland; Science for Life Laboratory, Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm 14183, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Vähärautio
authors.affiliation: Genome-Scale Biology Program and Department of Medical Genetics, Haartman Institute, University of Helsinki, Biomedicum, P.O. Box 63 (Haartmaninkatu 8), Helsinki FIN-00014, Finland.
authors.forename: Mervi
authors.initials: M
authors.lastname: Aavikko
authors.affiliation: Genome-Scale Biology Program and Department of Medical Genetics, Haartman Institute, University of Helsinki, Biomedicum, P.O. Box 63 (Haartmaninkatu 8), Helsinki FIN-00014, Finland.
authors.forename: Kati
authors.initials: K
authors.lastname: Kämpjärvi
authors.affiliation: Genome-Scale Biology Program and Department of Medical Genetics, Haartman Institute, University of Helsinki, Biomedicum, P.O. Box 63 (Haartmaninkatu 8), Helsinki FIN-00014, Finland.
authors.forename: Pia
authors.initials: P
authors.lastname: Vahteristo
authors.affiliation: Department of Biochemistry, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA.
authors.forename: Chongwoo A
authors.initials: CA
authors.lastname: Kim
authors.affiliation: Genome-Scale Biology Program and Department of Medical Genetics, Haartman Institute, University of Helsinki, Biomedicum, P.O. Box 63 (Haartmaninkatu 8), Helsinki FIN-00014, Finland.
authors.forename: Lauri A
authors.initials: LA
authors.lastname: Aaltonen
authors.affiliation: Institute of Biotechnology, University of Helsinki, Viikinkaari 1, P.O. Box 65, Helsinki FIN-00014, Finland. Electronic address: markku.varjosalo@helsinki.fi.
authors.forename: Markku
authors.initials: M
authors.lastname: Varjosalo
authors.affiliation: Genome-Scale Biology Program and Department of Pathology, Haartman Institute, University of Helsinki, Biomedicum, P.O. Box 63 (Haartmaninkatu 8), Helsinki FIN-00014, Finland; Science for Life Laboratory, Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm 14183, Sweden. Electronic address: jussi.taipale@ki.se.
authors.forename: Jussi
authors.initials: J
authors.lastname: Taipale
authors.affiliation: Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, Mail Code 8257, STRF, San Antonio, TX 78229-3900, USA. Electronic address: boyer@uthscsa.edu.
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Boyer
mesh_terms: D056745:Cyclin C / Q000378:metabolism; D056850:Cyclin-Dependent Kinase 8 / Q000378:metabolism*; D018844:Cyclin-Dependent Kinases / Q000378:metabolism*; D005260:Female; D057809:HEK293 Cells; D006801:Humans; D007889:Leiomyoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D056892:Mediator Complex / Q000235:genetics* / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D014594:Uterine Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology
chemical_list: D056745:Cyclin C; C460107:MED12 protein, human; D056892:Mediator Complex; C584437:CDK19 protein, human; D056850:Cyclin-Dependent Kinase 8; D018844:Cyclin-Dependent Kinases
references.citation: Mol Cell Biol. 2006 Dec;26(23):8667-82
references.pmid: 17000779
references.citation: Lancet. 2001 Jan 27;357(9252):293-8
references.pmid: 11214143
references.citation: Br J Cancer. 2012 Nov 6;107(10):1761-5
references.pmid: 23132392
references.citation: Nature. 2000 Sep 7;407(6800):102-6
references.pmid: 10993082
references.citation: Mol Cell. 2005 Aug 19;19(4):511-22
references.pmid: 16109375
references.citation: Mol Cell Biol. 2009 Feb;29(3):650-61
references.pmid: 19047373
references.citation: Trends Biochem Sci. 2010 Jun;35(6):315-22
references.pmid: 20299225
references.citation: Mol Cell. 2008 Aug 8;31(3):347-59
references.pmid: 18691967
references.citation: Nat Rev Genet. 2010 Nov;11(11):761-72
references.pmid: 20940737
references.citation: Curr Opin Genet Dev. 2011 Apr;21(2):225-30
references.pmid: 21330129
references.citation: Semin Cell Dev Biol. 2011 Sep;22(7):776-87
references.pmid: 21840410
references.citation: Nat Struct Mol Biol. 2010 Feb;17(2):194-201
references.pmid: 20098423
references.citation: Proc Natl Acad Sci U S A. 2012 Nov 27;109(48):19763-8
references.pmid: 23091001
references.citation: Nat Genet. 2012 May 20;44(6):685-9
references.pmid: 22610119
references.citation: Curr Opin Cell Biol. 2012 Jun;24(3):305-13
references.pmid: 22341791
references.citation: Science. 2013 Mar 29;339(6127):1546-58
references.pmid: 23539594
references.citation: Int J Cancer. 2012 Sep 15;131(6):E1044-7
references.pmid: 22532225
references.citation: Nat Struct Mol Biol. 2013 May;20(5):611-9
references.pmid: 23563140
references.citation: J Mol Biol. 2011 Sep 16;412(2):251-66
references.pmid: 21806996
references.citation: Nature. 2008 Sep 25;455(7212):552-6
references.pmid: 18794899
references.citation: Science. 2011 Oct 14;334(6053):252-5
references.pmid: 21868628
references.citation: Nature. 2008 Sep 25;455(7212):547-51
references.pmid: 18794900
references.citation: Genes Dev. 2009 Feb 15;23(4):439-51
references.pmid: 19240132
references.citation: Mol Syst Biol. 2009;5:237
references.pmid: 19156129
references.citation: J Biol Chem. 2006 May 19;281(20):14066-75
references.pmid: 16565090
references.citation: N Engl J Med. 2013 Jul 4;369(1):43-53
references.pmid: 23738515
references.citation: Trends Biochem Sci. 2005 May;30(5):235-9
references.pmid: 15896740
references.citation: Cell Rep. 2013 Apr 25;3(4):1306-20
references.pmid: 23602568
references.citation: J Mol Biol. 2005 Jul 29;350(5):833-42
references.pmid: 15979093