D-MTERF5 is a novel factor modulating transcription in Drosophila mitochondria.
The MTERF protein family comprises members from Metazoans and plants. All the Metazoan MTERF proteins characterized to date, including the mitochondrial transcription termination factors, play a key role in mitochondrial gene expression. In this study we report the characterization of Drosophila MTERF5 (D-MTERF5), a mitochondrial protein existing only in insects, probably originated from a duplication event of the transcription termination factor DmTTF. D-MTERF5 knock-down in D.Mel-2 cells alters transcript levels with an opposite pattern to that produced by DmTTF knock-down. D-MTERF5 is able to interact with mtDNA at the same sites contacted by DmTTF, but only in the presence of the termination factor. We propose that the two proteins participate in the transcription termination process, with D-MTERF5 engaged in relieving the block exerted by DmTTF. This hypothesis is supported also by D-MTERF5 homology modeling, which suggests that this protein contains protein-protein interaction domains. Co-regulation by DREF (DNA Replication-related Element binding Factor) of D-MTERF5 and DmTTF implies that expression of the two factors needs to be co-ordinated to ensure fine modulation of Drosophila mitochondrial transcription.
Dipartimento di Bioscienze, Biotecnologie e Scienze Farmacologiche, Università degli Studi di Bari Aldo Moro, Via Orabona 4, 70125 Bari, Italy.
Francesco
F
Bruni
Caterina
C
Manzari
Mariacristina
M
Filice
Paola
P
Loguercio Polosa
Matilde
M
Colella
Claudia
C
Carmone
Elena
E
Hambardjieva
Miguel
M
Garcia-Diaz
Palmiro
P
Cantatore
Marina
M
Roberti
D000818:Animals; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D008928:Mitochondria / Q000235:genetics*; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D054730:Protein Interaction Domains and Motifs; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D024101:Mitochondrial Proteins; C587162:mTerf5 protein, Drosophila