43 research outputs found
MTERF factors: a multifunction protein family
The MTERF family is a large protein family, identified in
metazoans and plants, which consists of four subfamilies,
MTERF1, 2, 3 and 4. Mitochondrial localisation was predicted
for the vast majority of MTERF family members and
demonstrated for the characterised MTERF proteins. The
main structural feature of MTERF proteins is the presence
of a modular architecture, based on repetitions of a 30-residue
module, the mTERF motif, containing leucine zipperlike
heptads. The MTERF family includes transcription
termination factors: human mTERF, sea urchin mtDBP and
Drosophila DmTTF. In addition to terminating transcription,
they are involved in transcription initiation and in the control
of mtDNA replication. This multiplicity of functions seems
to flank differences in the gene organisation of mitochondrial
genomes. MTERF2 and MTERF3 play antithetical roles in
controlling mitochondrial transcription: that is, mammalian
and Drosophila MTERF3 act as negative regulators, whereas
mammalian MTERF2 functions as a positive regulator. Both
proteins contact mtDNA in the promoter region, perhaps
establishing interactions, either mutual or with other factors.
Regulation of MTERF gene expression in human and Drosophila
depends on nuclear transcription factors NRF-2 and
DREF, respectively, and proceeds through pathways which
appear to discriminate between factors positively or negatively
acting in mitochondrial transcription. In this emerging
scenario, it appears that MTERF proteins act to coordinate
mitochondrial transcription