Four new subunits of the Dam1-Duo1 complex reveal novel functions in sister kinetochore biorientation.
We show here that Ask1p, Dad2p, Spc19p and Spc34p are subunits of the budding yeast Duo1p-Dam1p- Dad1p complex, which associate with kinetochores and localize along metaphase and anaphase spindles. Analysis of spc34-3 cells revealed three novel functions of the Duo1-Dam1p-Dad1p subunit Spc34p. First, SPC34 is required to establish biorientation of sister kinetochores. Secondly, SPC34 is essential to maintain biorientation. Thirdly, SPC34 is necessary to maintain an anaphase spindle independently of chromosome segregation. Moreover, we show that in spc34-3 cells, sister centromeres preferentially associate with the pre-existing, old spindle pole body (SPB). A similar preferential attachment of sister centromeres to the old SPB occurs in cells depleted of the cohesin Scc1p, a protein with a known role in facilitating biorientation. Thus, the two SPBs are not equally active in early S phase. We suggest that not only in spc34-3 and Deltascc1 cells but also in wild-type cells, sister centromeres bind after replication preferentially to microtubules organized by the old SPB. Monopolar attached sister centromeres are resolved to bipolar attachment in wild-type cells but persist in spc34-3 cells.
Janke
Carsten
C
The Beatson Institute for Cancer Research, CRC Beatson Laboratories, Glasgow G61 1BD, UK.
Ortíz
Jennifer
J
Tanaka
Tomoyuki U
TU
Lechner
Johannes
J
Schiebel
Elmar
E
D000705:Anaphase; D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D003598:Cytoskeletal Proteins; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018386:Kinetochores / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008938:Mitosis; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins; D021122:Protein Subunits; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D064249:Securin; D008941:Spindle Apparatus / Q000378:metabolism
C120363:ASK1 protein, Arabidopsis; D029681:Arabidopsis Proteins; C081071:CBF2 protein, S cerevisiae; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; C116003:DAM1 protein, S cerevisiae; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; C116004:DUO1 protein, S cerevisiae; C439311:Dad1 protein, S cerevisiae; D005656:Fungal Proteins; D008869:Microtubule-Associated Proteins; C112472:NDC80 protein, S cerevisiae; D009687:Nuclear Proteins; C578004:PDS1 protein, S cerevisiae; D010940:Plant Proteins; D021122:Protein Subunits; D029701:Saccharomyces cerevisiae Proteins; D064249:Securin