Yme2p is a mediator of nucleoid structure and number in mitochondria of the yeast Saccharomyces cerevisiae.
A large number of gene products have been identified that either directly or indirectly alter the inheritance of mitochondrial DNA. In yeast, we have used a unique genetic screen based on the transfer of DNA from mitochondria to nucleus to identify nuclear-encoded gene products that are targeted to mitochondria and impact the stable inheritance of mitochondrial DNA. A specific allele of one of these genes, yme2-4, prevents even the low wild-type rate of mitochondrial DNA transfer to the nucleus and imparts significant temperature-sensitive and respiratory-growth defects. Intra- and extragenic suppressors of the yme2-4 growth phenotypes were isolated and analysis of these interacting genes reveals that both YME2 and its suppressors influence the structure and number of mitochondrial nucleoids. The yme2-4 allele decreases the average number of mtDNA nucleoids found in cells and the sensitivity of DNA in toluene-treated mitochondria to digestion by DNA exonuclease, effects reversed by intra- and extragenic suppressors. The extragenic suppressor, a missense allele of ILV5, encodes an enzyme of the branched-chain amino acid biosynthetic pathway that is also a component of mitochondrial nucleoids. A null allele of ILV5 suppresses transfer of mitochondrial DNA to the nucleus and displays synthetic interactions with yme2-4.
Park
Sujin
S
Department of Molecular Biology, University of Wyoming, Laramie, WY 82071-3944, USA.
Hanekamp
Theodor
T
Thorsness
Mary K
MK
Thorsness
Peter E
PE
D000483:Alleles; D001483:Base Sequence; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D004272:DNA, Mitochondrial / Q000235:genetics / Q000378:metabolism; D005090:Exodeoxyribonucleases / Q000378:metabolism; D005800:Genes, Fungal; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D024101:Mitochondrial Proteins / Q000235:genetics* / Q000378:metabolism*; D009154:Mutation; D010641:Phenotype; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism*; D013489:Suppression, Genetic
D004271:DNA, Fungal; D004272:DNA, Mitochondrial; D024101:Mitochondrial Proteins; D029701:Saccharomyces cerevisiae Proteins; D005090:Exodeoxyribonucleases