Cdc16p, Cdc23p and Cdc27p form a complex essential for mitosis.

Abstract

Cdc16p, Cdc23p and Cdc27p are all essential proteins required for cell cycle progression through mitosis in Saccharomyces cerevisiae. All three proteins contain multiple tandemly repeated 34 amino acid tetratricopeptide repeats (TPRs). Using two independent assays, two‐hybrid analysis in vivo and co‐immunoprecipitation in vitro, we demonstrate that Cdc16p, Cdc23p and Cdc27p self associate and interact with one another to form a macromolecular complex. A temperature sensitive mutation in the most highly conserved TPR domain of Cdc27p results in a greatly reduced ability to interact with Cdc23p, but has no effect on interactions with wild‐type Cdc27p or Cdc16p. The specificity of this effect indicates that TPRs can mediate protein‐protein interactions and that this mutation may define an essential interaction for cell cycle progression in yeast. The conservation of at least two of the three proteins from yeast to man suggests that this protein complex is essential for mitosis in a wide range of eukaryotes.

Interaction of the Interferon-Induced PKR Protein Kinase with Inhibitory Proteins P58IPKand Vaccinia Virus K3L Is Mediated by Unique Domains: Implications for Kinase Regulation

“…Thus, one would predict that multimerization is a characteristic of this protein family. Indeed, the structurally related TPR proteins Cdc16, Cdc23, and Cdc27 of S. cerevisiae participate in TPR-dependent interactions in vivo, including homodimerization and formation of an essential mitotic heterotrimeric complex (46). To determine if P58 IPK formed homotypic complexes in vivo, we coexpressed various AD-P58 IPK deletion constructs with BD-P58 IPK wt in yeast cells and subjected the transfectants to the two-hybrid assay.…”

Regulation of the Anaphase-promoting Complex/Cyclosome bybimAAPC3and Proteolysis of NIMA

“…We will use the designation bimE APC1 for the gene and BIME APC1 for the protein. bimA encodes a member of the tetratricopeptide repeat family of proteins, being most similar to Schizosaccharomyces pombe nuc2 (Hirano et al, 1990(Hirano et al, , 1994 and Saccharomyces cerevisiae CDC27 (Sikorski et al, 1990;Lamb et al, 1994), which was recently termed APC3 APC/C functions as an E3 ubiquitin ligase, which specifically targets proteins (such as mitotic cyclins) for degradation in a destruction box (D box)-dependent manner (Glotzer et al, 1991;King et al, 1996b) through the ubiquitin-proteasome pathway, to promote initiation of anaphase and exit from mitosis into G1 (for reviews see Murray, 1995;King et al, 1996a;Hershko, 1997;Townsley and Ruderman, 1998). APC/C activity is cell cycle regulated (Hershko et al, 1994; potentially by reversible phosphorylation (Lahav-Baratz et al, 1995) of certain subunits .…”

“…The bimE and bimA genes were originally defined by temperature-sensitive mutations in functions required for normal progression through mitosis in Aspergillus nidulans (Morris, 1976;Osmani et al, 1988;Engle et al, 1990;O'Donnell et al, 1991) and were subsequently found to encode highly conserved proteins whose homologues have been isolated from many organisms ranging from fungi to humans (Hirano et al, 1990(Hirano et al, , 1994Mirabito and Morris, 1993;Lamb et al, 1994;Starborg et al, 1994;King et al, 1995;. Most significantly, they were recently identified as components of the anaphase-promoting complex (APC) (King et al, 1995;Peters et al, 1996;.…”

The C-Terminal Half of Saccharomyces cerevisiae Mad1p Mediates Spindle Checkpoint Function, Chromosome Transmission Fidelity and CEN Association

“…Xenopus laevis and Schizosac- Ikui et al 2002;Liu et al 2003) and may also Western blotting: Protein extracts from the Mad1-GFP strains reside at the NPC. The NPC is a proteinacious portal were made from early logarithmic phase cultures grown in YEPD through which proteins and RNA traffic between the at 30Њ as described previously (Lamb et al 1994). Following nucleoplasm and the cytoplasm (Fabre and Hurt separation with SDS-PAGE and transfer to PVDF membrane, 1997).…”