Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.22 (cdc2)
 8,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have isolated two murine cDNAs designated PCTAIRE-1 and -3 which encode putative serine/threonine-specific protein kinases. The predicted products of PCTAIRE-1 and -3 are 65% homologous and are organized into a core 295-residue kinase domain flanked by unique 161 and 117 amino acid N-terminal and 40 and 39 amino acid C-terminal domains respectively. The kinase domains are approximately 50-55% homologous to members of the cdc2/CDC28 kinase gene family, and each contains a cysteine-for-serine substitution within the conserved PSTAIRE motif. PCTAIRE-1 was ubiquitously expressed as a predominant 3.0-kb transcript and a minor 2.2-kb mRNA resulting from differential polyadenylation. In contrast, PCTAIRE-3 exhibited a more restricted pattern of expression with a single 3.0-kb mRNA detected in brain, kidney and intestine. The PCTAIRE-1 and -3 products produced by in vitro transcription-translation failed to bind to p13suc1 but were precipitated by antibodies directed to Schizosaccharomyces pombe p34cdc2 or to the human PSTAIRE motif. Thus, PCTAIRE-1 and -3 are members of a novel subfamily of cdc2/CDC28-related protein kinases.
 ...
PMID:PCTAIRE-1 and PCTAIRE-3, two members of a novel cdc2/CDC28-related protein kinase gene family. 143 47

Overexpression of wild-type p53 in mammalian cells blocks growth. We show here that the overexpression of wild-type human p53 in the fission yeast Schizosaccharomyces pombe also blocks growth, whereas the overexpression of mutant forms of p53 does not. The p53 polypeptide is located in the nucleus and is phosphorylated at both the cdc2 site and the casein kinase II site in S. pombe. A new dominant mutation of p53, resulting in the change of a cysteine to an arginine at amino acid residue 141, was identified. The results presented here demonstrate that S. pombe could provide a simple system for studying the mechanism of action of human p53.
 ...
PMID:Human p53 inhibits growth in Schizosaccharomyces pombe. 154 3

Genetic and biochemical studies have indicated that the cdc25 protein controls the entry into mitosis by triggering tyrosine dephosphorylation of the cdc2 protein kinase. We show that the isolated cdc25 protein can catalyze dephosphorylation of several model phosphatase substrates, including p-nitrophenyl phosphate and two distinct tyrosine-phosphorylated peptides. The cdc25-dependent cleavage reaction closely resembles dephosphorylation by known tyrosine phosphatases: the reaction requires a reducing agent, shows high sensitivity to sodium vanadate, and proceeds efficiently in the presence of metal chelators. Moreover, the phosphatase activity of the cdc25 protein is eliminated by treatment with N-ethylmaleimide or by alteration of a single conserved cysteine residue by site-directed mutagenesis. These observations indicate that the cdc25 protein can function as a tyrosine phosphatase in the absence of any other protein.
 ...
PMID:The cdc25 protein contains an intrinsic phosphatase activity. 165 74

We used the interaction trap, a yeast genetic selection for interacting proteins, to isolate human cyclin-dependent kinase interactor 1 (Cdi1). In yeast, Cdi1 interacts with cyclin-dependent kinases, including human Cdc2, Cdk2, and Cdk3, but not with Ckd4. In HeLa cells, Cdi1 is expressed at the G1 to S transition, and the protein forms stable complexes with Cdk2. Cdi1 bears weak sequence similarity to known tyrosine and dual specificity phosphatases. In vitro, Cdi1 removes phosphate from tyrosine residues in model substrates, but a mutant protein that bears a lesion in the putative active site cysteine does not. Overexpression of wild-type Cdi1 delays progression through the cell cycle in yeast and HeLa cells; delay is dependent on Cdi1 phosphatase activity. These experiments identify Cdi1 as a novel type of protein phosphatase that forms complexes with cyclin-dependent kinases.
 ...
PMID:Cdi1, a human G1 and S phase protein phosphatase that associates with Cdk2. 824 50

G0S24 is a member of a set of genes (putative G0/G1 switch regulatory genes) that are expressed transiently within 1-2 hr of the addition of lectin or cycloheximide to human blood mononuclear cells. Comparison of a full-length cDNA sequence with the corresponding genomic sequence reveals an open reading frame of 326 amino acids, distributed across two exons. Potential phosphorylation sites include the sequence PSPTSPT, which resembles an RNA polymerase II repeat reported to be a target of the cell cycle control kinase cdc2. Comparison of the derived protein sequence with those of rodent homologs allows classification into three groups. Group 1 contains G0S24 and the rat and mouse TIS11 genes (also known as TTP, Nup475, and Zfp36). Members of this group have three tetraproline repeats. Groups 1 and 2 have a serine-rich region and an "arginine element" (RRLPIF) at the carboxyl terminus. All groups contain cysteine- and histidine-rich putative zinc finger domains and a serine-phenylalanine "SFS" domain similar to part of the large subunit of eukaryotic RNA polymerase II. Comparison of group 1 human and mouse genomic sequences shows high conservation in the 5' flank and exons. A CpG island suggests expression in the germ line. G0S24 has potential sites for transcription factors in the 5' flank and intron; these include a serum response element. Protein and genomic sequences show similarities with those of a variety of proteins involved in transcription, suggesting that the G0S24 product has a similar role.
 ...
PMID:A human putative lymphocyte G0/G1 switch gene homologous to a rodent gene encoding a zinc-binding potential transcription factor. 842 74

Human Cdc25 proteins are dual specific protein phosphatases that play important roles in cell cycle regulation. In this study, the catalytic mechanism and substrate binding specificity of human Cdc25A and -B proteins were investigated by site-directed and deletion mutagenesis methods. Mutations of the cysteine or the arginine residues in the active site motif abolished the Cdc25 phosphatase activity. However, the cysteine mutation in both Cdc25A and -B created enzymes that still retain the ability to bind their substrates. This allowed us to test the ability of Cdc25A and -B to bind various cyclin-Cdk complexes in vitro. While Cdc25A Cys --> Ser could interact with cyclin A-Cdk2, cyclin B-Cdc2, and cyclin E-Cdk2 strongly, Cdc25B mutant was only found to bind to cyclin A-Cdk2 at significant levels. We also identified Arg452 and Ser449 as two crucial residues that could be directly involved in the molecular interactions between Cdc25 and cyclin-Cdk proteins. Deletion mutagenesis data also indicate that the phosphatase catalytic domains of Cdc25A and -B proteins are located within their carboxyl terminus.
 ...
PMID:Roles of active site residues and the NH2-terminal domain in the catalysis and substrate binding of human Cdc25. 861 91

The cyclin-dependent kinase inhibitor p21Cip1/Waf1 is responsible for the p53-dependent growth arrest of cells in G1 phase following DNA damage. In the present study we investigated regions of p21 involved in inhibition of the G1/S phase cyclin-dependent kinase, cyclin E/Cdk2, as well as regions of p21 important for binding to this kinase and recombinant PCNA. To perform these studies we synthesized a series of overlapping peptides spanning the entire p21 sequence and used them in in vitro assays with cyclin E/Cdk2-immune complexes and with recombinant p21 and PCNA proteins. One amino-terminal p21 peptide spanning amino acids 15-40, antagonized p21 binding and inhibition of cyclin E/Cdk2 kinase. Antagonism of p21 binding was, however, lost in a similar peptide lacking amino acids 15-20, or in a peptide in which cysteine-18 was substituted for a serine. These results suggest that this peptide region is important for p21 interaction with cyclin E/Cdk2. A second peptide (amino acids 58-77) also antagonized p21-activity, but this peptide did not affect the ability of p21 to interact with cyclin E/Cdk2. A region of p21 larger than 26 amino acids is presumably required for Cdk-inhibition because none of the peptides we tested inhibited cyclin E/Cdk2. We also found that a peptide spanning amino acids 21-45 bound recombinant p21 in ELISA assays, and additional studies revealed a requirement for amino acids 26 through 45 for this interaction. A p21 peptide spanning amino acids 139-164 was found to bind PCNA in a filter binding assay and this peptide suppressed recombinant p21-PCNA interaction. Conformational analysis revealed that peptides spanning amino acids 21-45 and 139-164 tended towards an alpha-helical conformation in trifluoroethanol buffer, indicating that these regions are probably in a coiled conformation in the native protein. Taken together, our results provide an insight into domains of p21 that are involved in cyclin E/Cdk2 and PCNA interaction. Our results also suggest that a potential p21 dimerization domain may lie in the amino-terminus of p21. Continued exploration of these domains could prove useful in assessing p21-mimetic strategies for cancer treatment.
 ...
PMID:Characterization of p21Cip1/Waf1 peptide domains required for cyclin E/Cdk2 and PCNA interaction. 863 17

The tumor suppressor p16INK4A with eight N-terminal amino acids deleted (p16/delta 1-8) was expressed in Escherichia coli without any fusion artifacts and purified. The integrity of p16/delta 1-8 was confirmed by mass spectrometry, and its activity was demonstrated by in vitro cdk4 inhibition assay. Various physical methods were used to characterize the molecular and structural properties of p16/delta 1-8. The protein was found to oligomerize in vitro, as demonstrated by gel electrophoresis, mass spectrometry, and NMR. Various approaches, including changes of concentration and pH, additions of salts, detergents, and various organic solvents, and construction of a C-terminal deletion mutant and a cysteine mutant were used to try to reduce the extent of oligomerization. Only decreasing the protein concentration was found to reduce oligomerization. The affinity between p16 molecules in vivo was demonstrated by the yeast two-hybrid system. The protein was found to be very unstable on the basis of urea- and guanidinium chloride-induced denaturation studies monitored by NMR and CD, respectively. Despite these unfavorable properties, total NMR assignments were accomplished with uniform 13C and 15N isotope labeling. All multidimensional NMR experiments were performed at a very low concentration of 0.2 mM. The secondary structure was then determined from the NMR data. The results of NMR and CD studies indicate that the protein is highly alpha-helical, and the ankyrin repeat sequences show helix-turn-helix structures. This is the first structural information obtained for the important motif of ankyrin repeats. Overall, p16/delta 1-8 appears to be conformationally flexible. In order to understand the structural basis of the functional changes for some mutants existing in tumor cells, several missense mutants of p16/delta 1-8 were constructed. Four of them were expressed at high levels and purified. The molecular and structural properties of these mutants were analyzed by CD and NMR and compared with the corresponding properties of wild-type p16/delta 1-8. The results suggest that the functional changes in P114L and G101W are likely to be related to global conformational changes. In addition, we have demonstrated that the tendency of aggregation increases significantly by a single D84H mutation.
 ...
PMID:Tumor suppressor p16INK4A: structural characterization of wild-type and mutant proteins by NMR and circular dichroism. 875 27

The induction of apoptosis by the Fas/APO-1 receptor is important for T-cell-mediated cytotoxicity and down-regulation of immune responses. Binding of Fas ligand to the Fas/APO-1 receptor transduces an apoptotic signal that requires activation of interleukin 1beta-converting enzyme (ICE) and CPP32beta, members of a family of cysteine proteases that are evolutionarily conserved determinants of cell death. We report here that Fas/APO-1-triggered apoptosis involves ICE-mediated activation of p34cdc2 kinase. Ligation of the Fas receptor resulted in the rapid stimulation of ICE proteolytic activity and activation of p34cdc2 kinase. Specific tetrapeptide inhibitors of ICE (Acetyl-Tyr-Val-Ala-Asp-chloromethylketone) or CPP32beta (Acetyl-Asp-Glu-Val-Asp-aldehyde) prevented the anti-Fas antibody-mediated activation of p34cdc2 and inhibited apoptosis. Inhibition of p34cdc2 activity by transient overexpression of a dominant-negative cdc2 construct or human WEE1 kinase inhibited Fas-mediated apoptosis. These results suggest that activation of p34cdc2 kinase is a critical determinant of cell death mediated by Fas and ICE family proteases.
 ...
PMID:Requirement of p34cdc2 kinase for apoptosis mediated by the Fas/APO-1 receptor and interleukin 1beta-converting enzyme-related proteases. 884 Sep 58

Destruction of mitotic cyclins by ubiquitin-dependent proteolysis is required for cells to complete mitosis and enter interphase of the next cell cycle. In clam eggs, this process is catalyzed by a cyclin-selective ubiquitin carrier protein, E2-C, and the cyclosome/anaphase promoting complex (APC), a 20S particle containing cyclin-selective ubiquitin ligase activity. Here we report cloning a human homolog of E2-C, UbcH10, which shares 61% amino acid identity with clam E2-C and can substitute for clam E2-C in vitro. Dominant-negative clam E2-C and human UbcH10 proteins, created by altering the catalytic cysteine to serine, inhibit the in vitro ubiquitination and destruction of cyclin B in clam oocyte extracts. When transfected into mammalian cells, mutant UbcH10 inhibits the destruction of both cyclin A and B, arrests cells in M phase, and inhibits the onset of anaphase, presumably by blocking the ubiquitin-dependent proteolysis of proteins responsible for sister chromatid separation. Thus, E2-C/UbcH10-mediated ubiquitination is involved in both cdc2 inactivation and sister chromatid separation, processes that are normally coordinated during exit from mitosis.
 ...
PMID:Dominant-negative cyclin-selective ubiquitin carrier protein E2-C/UbcH10 blocks cells in metaphase. 912


1 2 3 4 5 6 7 Next >>