p13suc1 acts in the fission yeast cell division cycle as a component of the p34cdc2 protein kinase.

Abstract

cdc2+ encodes a protein kinase that is required during both G1 and G2 phases of the cell division cycle in fission yeast. suc1+ is an essential gene that was originally identified as a plasmid‐borne sequence that could rescue certain temperature‐sensitive cdc2 mutants. To investigate the role of the suc1+ gene product in the cell cycle p13suc1 has been expressed in Escherichia coli and purified. An immunoaffinity purified anti‐p13suc1 polyclonal serum has been prepared and used to identify p13suc1 in fission yeast. The abundance of this protein did not alter either during the cell cycle or during entry into stationary phase. p13suc1 was found in yeast lysates in a complex with the cdc2+ gene product. Approximately 5% of cellular p34cdc2 was associated with p13suc1, and this fraction of p34cdc2 was active as a protein kinase. The stability of the complex was disrupted in yeast strains carrying temperature‐sensitive alleles of cdc2 that are suppressible by overexpression of suc1+. The level of association between p13suc1 and p34cdc2 was not affected by cell cycle arrest in adverse nutritional conditions. p13suc1 is not a substrate of the p34cdc2 protein kinase. We propose instead that it acts as a regulatory component of p34cdc2 that facilitates interaction with other proteins.

Identification of a p130 domain mediating interactions with cyclin A/cdk 2 and cyclin E/cdk 2 complexes

“…p13 suc1 is a subunit of S pombe p34 cdc2 and binds cdc2 and cdk2 with high a nity (Brizuela et al, 1987). Preclearing cyclin E-infected SF9 cells by incubation with p13 suc1 beads did not reduce the interaction of cyclin E with GST-p130 (593 ± 1139) (data not shown).…”

Subunit rearrangement of the cyclin-dependent kinases is associated with cellular transformation.

“…In many of the cell cycle kinase complexes p21 is not simply altered in its relative stoichiometry in transformed cells, but it is replaced by a different polypeptide p19). The possibility of any of these proteins bearing any relationship to the cdc2-associated p l3SUcl/CKS (Brizuela et al 1987;Draetta et al 1987;Richardson et al 1990) awaits molecular cloning of p21, p19, and p16.…”

The bacterial cytolethal distending toxin (CDT) triggers a G2 cell cycle checkpoint in mammalian cells without preliminary induction of DNA strand breaks

“…A nity chromatography on p13 suc1 Sepharose beads was used to recover the CDK1/cyclin B complexes. P13 Sepharose beads were prepared according to Brizuela et al (1987). A 20 ml volume of beads were incubated with 200 mg of cell lysate for 3 h at 48C on a rotator in 1 ml ®nal volume of lysis bu er (50 mM Tris HCl pH 7.5, 250 mM NaCl, 5 mM EDTA, 0.1% Triton X100, 1 mM dithiothreitol (DTT) supplemented with protease inhibitors (1 mg/ml leupeptin, 1 mg/ml aprotinine, 10 mg/ml soybean trypsin inhibitor, 10 mg/ml tosyl lysine chloromethyl ketone (TLCK), 10 mg/ml tosyl phenylalanine chloromethyl ketone (TPCK), 0.17 mg/ml phenyl methyl sulfonyl¯uoride (PMSF) and phosphatases inhibitors (50 mM NaF, 0.1 mM Na 3 VO 4 , 10 mM b-glycerophosphate).…”