Chromosomal association of the Smc5/6 complex reveals that it functions in differently regulated pathways.
The SMC protein complexes safeguard genomic integrity through their functions in chromosome segregation and repair. The chromosomal localization of the budding yeast Smc5/6 complex determined here reveals that the complex works specifically on the duplicated genome in differently regulated pathways. The first controls the association to centromeres and chromosome arms in unchallenged cells, the second regulates the association to DNA breaks, and the third directs the complex to the chromosome arm that harbors the ribosomal DNA arrays. The chromosomal interaction pattern predicts a function that becomes more important with increasing chromosome length and that the complex's role in unchallenged cells is independent of DNA damage. Additionally, localization of Smc6 to collapsed replication forks indicates an involvement in their rescue. Altogether this shows that the complex maintains genomic integrity in multiple ways, and evidence is presented that the Smc5/6 complex is needed during replication to prevent the accumulation of branched chromosome structures.
Betts Lindroos
Hanna
H
Department of Cell and Molecular Biology, Karolinska Institute, 171 77 Stockholm, Sweden.
Ström
Lena
L
Department of Cell and Molecular Biology, Karolinska Institute, 171 77 Stockholm, Sweden.
Itoh
Takehiko
T
Research Center for Advanced Science and Technology, Mitsubishi Research Institute, Inc., Tokyo 100-8141, Japan.
Katou
Yuki
Y
Gene Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, 226-8501 Yokohama, Japan.
Shirahige
Katsuhiko
K
Gene Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, 226-8501 Yokohama, Japan. Electronic address: kshirahi@bio.titech.ac.jp.
Sjögren
Camilla
C
Department of Cell and Molecular Biology, Karolinska Institute, 171 77 Stockholm, Sweden. Electronic address: camilla.sjogren@ki.se.
D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002503:Centromere / Q000378:metabolism; D020090:Chromosome Segregation / Q000502:physiology; D015825:Chromosomes, Fungal / Q000235:genetics / Q000378:metabolism*; D004249:DNA Damage / Q000502:physiology; D004260:DNA Repair / Q000502:physiology; D004261:DNA Replication / Q000502:physiology; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D016681:Genome, Fungal / Q000502:physiology*; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
D018797:Cell Cycle Proteins; D004271:DNA, Fungal; D046912:Multiprotein Complexes; C486627:SMC5 protein, S cerevisiae; C486631:SMC6 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins