Pds5 cooperates with cohesin in maintaining sister chromatid cohesion.
BACKGROUND
Sister chromatid cohesion depends on a complex called cohesin, which contains at least four subunits: Smc1, Smc3, Scc1 and Scc3. Cohesion is established during DNA replication, is partially dismantled in many, but not all, organisms during prophase, and is finally destroyed at the metaphase-to-anaphase transition. A quite separate protein called Spo76 is required for sister chromatid cohesion during meiosis in the ascomycete Sordaria. Spo76-like proteins are highly conserved amongst eukaryotes and a homologue in Aspergillus nidulans, called BimD, is required for the completion of mitosis. The isolation of the cohesin subunit Smc3 as a suppressor of BimD mutations suggests that Spo76/BimD might function in the same process as cohesin.


RESULTS
We show here that the yeast homologue of Spo76, called Pds5, is essential for establishing sister chromatid cohesion and maintaining it during metaphase. We also show that Pds5 co-localizes with cohesin on chromosomes, that the chromosomal association of Pds5 and cohesin is interdependent, that Scc1 recruits Pds5 to chromosomes in G1 and that its cleavage causes dissociation of Pds5 from chromosomes at the metaphase-to-anaphase transition.


CONCLUSIONS
Our data show that Pds5 functions as part of the same process as cohesin. Sequence similarities and secondary structure predictions indicate that Pds5 consists of tandemly repeated HEAT repeats, and might therefore function as a protein-protein interaction scaffold, possibly in the cohesin-DNA complex assembly.
Panizza
S
S
Research Institute of Molecular Pathology, Dr Bohr-gasse 7, A-1030 Vienna, Austria.
Tanaka
T
T
Hochwagen
A
A
Eisenhaber
F
F
Nasmyth
K
K
D000818:Animals; D015153:Blotting, Western; D002453:Cell Cycle / Q000502:physiology; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002469:Cell Separation; D002842:Chromatids / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone; D004247:DNA / Q000378:metabolism; D005434:Flow Cytometry; D005656:Fungal Proteins; D017930:Genes, Reporter; D006801:Humans; D046911:Macromolecular Substances; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010750:Phosphoproteins; D011233:Precipitin Tests; D017434:Protein Structure, Tertiary; D021122:Protein Subunits; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D000097722:Cohesins
D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D004247:DNA; D005656:Fungal Proteins; D046911:Macromolecular Substances; D009687:Nuclear Proteins; D010750:Phosphoproteins; D021122:Protein Subunits; D016271:Proto-Oncogene Proteins c-myc; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D000097722:Cohesins; C490529:MCD1 protein, S cerevisiae; C427726:PDS5 protein, S cerevisiae