title: Yeast and human mitochondrial helicases.
abstract: Mitochondria are semiautonomous organelles which contain their own genome. Both maintenance and expression of mitochondrial DNA require activity of RNA and DNA helicases. In Saccharomyces cerevisiae the nuclear genome encodes four DExH/D superfamily members (MSS116, SUV3, MRH4, IRC3) that act as helicases and/or RNA chaperones. Their activity is necessary for mitochondrial RNA splicing, degradation, translation and genome maintenance. In humans the ortholog of SUV3 (hSUV3, SUPV3L1) so far is the best described mitochondrial RNA helicase. The enzyme, together with the matrix-localized pool of PNPase (PNPT1), forms an RNA-degrading complex called the mitochondrial degradosome, which localizes to distinct structures (D-foci). Global regulation of mitochondrially encoded genes can be achieved by changing mitochondrial DNA copy number. This way the proteins involved in its replication, like the Twinkle helicase (c10orf2), can indirectly regulate gene expression. Here, we describe yeast and human mitochondrial helicases that are directly involved in mitochondrial RNA metabolism, and present other helicases that participate in mitochondrial DNA replication and maintenance. This article is part of a Special Issue entitled: The Biology of RNA helicases - Modulation for life.
authors: Institute of Genetics and Biotechnology, University of Warsaw, Warsaw, Poland.
authors: Roman J
authors: RJ
authors: Szczesny
authors: Magdalena A
authors: MA
authors: Wojcik
authors: Lukasz S
authors: LS
authors: Borowski
authors: Maciej J
authors: MJ
authors: Szewczyk
authors: Magda M
authors: MM
authors: Skrok
authors: Pawel
authors: P
authors: Golik
authors: Piotr P
authors: PP
authors: Stepien
mesh_terms: D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism; D004261:DNA Replication; D004272:DNA, Mitochondrial / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008928:Mitochondria / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D012313:RNA / Q000235:genetics / Q000378:metabolism; D020365:RNA Helicases / Q000235:genetics* / Q000378:metabolism*; D012326:RNA Splicing; D000077278:RNA, Mitochondrial; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D004272:DNA, Mitochondrial; D000077278:RNA, Mitochondrial; D029701:Saccharomyces cerevisiae Proteins; D012313:RNA; D004265:DNA Helicases; C000594746:Irc3 protein, S cerevisiae; D020365:RNA Helicases