title: Human mitochondrial transcription revisited: only TFAM and TFB2M are required for transcription of the mitochondrial genes in vitro.
abstract: Human mitochondrial transcription is driven by a single subunit RNA polymerase and a set of basal transcription factors. The development of a recombinant in vitro transcription system has allowed for a detailed molecular characterization of the individual components and their contribution to transcription initiation. We found that TFAM and TFB2M act synergistically and increase transcription efficiency 100-200-fold as compared with RNA polymerase alone. Both the light-strand promoter (LSP) and the HSP1 promoters displayed maximal levels of in vitro transcription when TFAM was present in an amount equimolar to the DNA template. Importantly, we did not detect any significant transcription activity in the presence of the TFB2M paralog, TFB1M, or when templates containing the putative HSP2 promoter were used. These data confirm previous observations that TFB1M does not function as a bona fide transcription factor and raise questions as to whether HSP2 serves as a functional promoter in vivo. In addition, we did not detect transcription stimulation by the ribosomal protein MRPL12. Thus, only two essential initiation factors, TFAM and TFB2M, and two promoters, LSP and HSP1, are required to drive transcription of the mitochondrial genome.
authors.affiliation: Department of Cell Biology, School of Osteopathic Medicine, University of Medicine and Dentistry of New Jersey, Stratford, New Jersey 08084, USA.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Litonin
authors.forename: Marina
authors.initials: M
authors.lastname: Sologub
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Shi
authors.forename: Maria
authors.initials: M
authors.lastname: Savkina
authors.forename: Michael
authors.initials: M
authors.lastname: Anikin
authors.forename: Maria
authors.initials: M
authors.lastname: Falkenberg
authors.forename: Claes M
authors.initials: CM
authors.lastname: Gustafsson
authors.forename: Dmitry
authors.initials: D
authors.lastname: Temiakov
mesh_terms: D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D007313:Insecta; D008780:Methyltransferases / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism*; D008954:Models, Biological; D008957:Models, Genetic; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D004268:DNA-Binding Proteins; D024101:Mitochondrial Proteins; C499631:TFAM protein, human; D014157:Transcription Factors; D004247:DNA; D008780:Methyltransferases; C462443:TFB2M protein, human; D012321:DNA-Directed RNA Polymerases
references.citation: Nat Genet. 2003 Jan;33(1):23-4
references.pmid: 12496758
references.citation: Proc Natl Acad Sci U S A. 1985 May;82(9):2660-4
references.pmid: 3857608
references.citation: Cell. 1983 Aug;34(1):151-9
references.pmid: 6883508
references.citation: J Biol Chem. 2010 Feb 5;285(6):3957-3964
references.pmid: 19920143
references.citation: Nat Genet. 2002 Jul;31(3):289-94
references.pmid: 12068295
references.citation: Cell Metab. 2009 Apr;9(4):386-97
references.pmid: 19356719
references.citation: Nucleic Acids Res. 2007;35(12):4042-54
references.pmid: 17557812
references.citation: Cell. 2009 Nov 25;139(5):934-44
references.pmid: 19945377
references.citation: Mol Cell Biol. 2003 Aug;23(16):5816-24
references.pmid: 12897151
references.citation: Cell. 2007 Jul 27;130(2):273-85
references.pmid: 17662942
references.citation: J Biol Chem. 2008 Feb 8;283(6):3665-3675
references.pmid: 18063578
references.citation: J Biol Chem. 2004 Oct 22;279(43):44239-42
references.pmid: 15342628
references.citation: Mol Cell Biol. 1995 Dec;15(12):7032-42
references.pmid: 8524270
references.citation: Nucleic Acids Res. 2004 Nov 16;32(20):6015-27
references.pmid: 15547250
references.citation: Yeast. 2009 Aug;26(8):423-40
references.pmid: 19536766
references.citation: Cell. 1987 Jul 17;50(2):247-58
references.pmid: 3594571
references.citation: J Biol Chem. 1996 May 10;271(19):11468-76
references.pmid: 8626705
references.citation: J Biol Chem. 2005 Apr 29;280(17):16815-20
references.pmid: 15749697
references.citation: Cell Metab. 2009 Jun;9(6):499-511
references.pmid: 19490905
references.citation: J Biol Chem. 2007 Apr 27;282(17):12610-8
references.pmid: 17337445
references.citation: Nucleic Acids Res. 2004 Jan 09;32(1):255-62
references.pmid: 14715923
references.citation: Trends Biochem Sci. 2007 Mar;32(3):111-7
references.pmid: 17291767
references.citation: Cell. 2005 Dec 29;123(7):1227-40
references.pmid: 16377564
references.citation: Nucleic Acids Res. 2006;34(22):6404-15
references.pmid: 17130166
references.citation: Mol Cell. 2006 Dec 28;24(6):813-25
references.pmid: 17189185
references.citation: Protoplasma. 2004 Jun;223(2-4):175-82
references.pmid: 15221522
references.citation: Biochim Biophys Acta. 1995 May 24;1271(1):127-34
references.pmid: 7599198
references.citation: Hum Mol Genet. 2004 May 1;13(9):935-44
references.pmid: 15016765
references.citation: Proc Natl Acad Sci U S A. 1986 Sep;83(17):6277-81
references.pmid: 3018722
references.citation: Proc Natl Acad Sci U S A. 2008 Aug 12;105(32):11122-7
references.pmid: 18685103
references.citation: Proc Natl Acad Sci U S A. 1982 Dec;79(23):7195-9
references.pmid: 6185947
references.citation: EMBO J. 2004 Nov 24;23(23):4606-14
references.pmid: 15526033
references.citation: J Biol Chem. 1984 Mar 25;259(6):3909-15
references.pmid: 6323446