A single mouse gene encodes the mitochondrial transcription factor A and a testis-specific nuclear HMG-box protein.
Mitochondrial transcription factor A (mtTFA) is a key regulator of mammalian mitochondrial DNA transcription. We report here that a testis-specific isoform of mouse mtTFA lacks the mitochondrial targeting sequence and is present in the nucleus of spermatocytes and elongating spermatids, thus representing the first reported mammalian gene encoding protein isoforms targeted for the mitochondria or the nucleus. The presence of the mitochondrial transcriptional activator in the nucleus raises the possibility of a role for this protein in both genetic systems. Mutations in the nuclear mtTFA gene may therefore exhibit phenotypic consequences due to altered function in either or both genetic compartments.
Larsson
N G
NG
Department of Development Biology, Bechman Center for Molecular and Genetic Medicine, Stanford University School of Medicine, Calfornia 94305-5427, USA.
Garman
J D
JD
Oldfors
A
A
Barsh
G S
GS
Clayton
D A
DA
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000737:chemistry / Q000235:genetics; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D006609:High Mobility Group Proteins / Q000235:genetics*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008928:Mitochondria / Q000737:chemistry; D024101:Mitochondrial Proteins; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013090:Spermatocytes / Q000737:chemistry; D013737:Testis / Q000737:chemistry* / Q000378:metabolism; D014157:Transcription Factors / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D006609:High Mobility Group Proteins; D024101:Mitochondrial Proteins; D009687:Nuclear Proteins; C081930:Tfam protein, mouse; D014157:Transcription Factors; C422562:mitochondrial transcription factor A