Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.5.1.18 (glutathione S-transferase)
22,582 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ag-NOR proteins are silver-stainable proteins in the nucleolar organizer regions and are used to distinguish benign from malignant tumors. B23 and C23 are the two major Ag-NOR proteins. This study shows that only one of the two acidic clusters of B23 is responsible for its silver staining property. Fusion of this region of B23 (amino acids 161-188) to glutathione S-transferase produced an Ag-NOR positive fusion protein. The same result was obtained when amino acids 233-277 of C23 was fused with glutathione S-transferase. The aspartate residues, but not the glutamate residues, were found to be primarily responsible for the silver staining of the acidic clusters.
...
PMID:Specific aspartic acid-rich sequences are responsible for silver staining of nucleolar proteins. 753 2

By using the cross-linking reagent, DSP, efforts were made to identify the protein(s) that interact with nucleophosmin/B23. A cross-linked protein complex at molecular weight of about 140 kDa was recognized by both nucleophosmin/B23 and protein C23 MAbs. Both C23 and nucleophosmin/B23 could be detected from the cross-linked complex immunoprecipitated by C23 MAb. The association between nucleophosmin/B23 and protein C23 while being observed at interphase and cytokinesis, was not detected in prometaphase and metaphase cells. Interactions of nucleophosmin/B23 with C23 not only could be found in cells in which nucleophosmin/B23 and C23 were both mainly localized to the nucleolus, but also in cells in which nucleophosmin/B23 and C23 had translocated from the nucleolus to the nucleoplasm during actinomycin D-induced cell growth inhibition. The purified recombinant GST-B23 being phosphorylated by prometaphase cell extracts (nocodazole-arrested cells) or cdc2 kinase could still be co-immunoprecipitated with C23. Consequently, the fact that nucleophosmin/B23 did not interact with C23 during mitosis could not be explained simply by mitotic phosphorylation of nucleophosmin/B23. Our findings suggest some possibilities for further elucidation of the actions of nucleophosmin/B23 and protein C23 in cell cycle progression and cell growth.
...
PMID:In vivo interaction of nucleophosmin/B23 and protein C23 during cell cycle progression in HeLa cells. 1050 77

The recombinant GST-nucleophosmin/B23 and the truncated mutants were tested for phosphorylation in cell-free extracts of G(2) and M phases or by purified kinases. Our results indicated that a threonine residue at amino acids (a.a.) 185-240 was phosphorylated by cdc2 kinase during the entry of mitosis while the serine phosphorylation site at the middle acidic portion of the molecule (a. a. 83-152) was phosphorylated by casein kinase II during G(2) phase. Our results also showed that there was possibly another serine phosphorylation at site other than the middle portion of nucleophosmin/B23 (a.a. 83-152) during the entry of cells into mitosis. The demonstration of the characteristic changes in phosphorylation of nucleophosmin/B23 during the cell cycle implicates important role of nucleophosmin/B23 in the control of the fate of nucleoli and cell growth.
...
PMID:Different kinases phosphorylate nucleophosmin/B23 at different sites during G(2) and M phases of the cell cycle. 1077 44

Myf5 is a nuclear protein and one of the basic helix-loop-helix (bHLH) myogenic factors that play an important role in muscle specification and differentiation. The motif responsible for the nuclear translocation of Myf5 was unknown. Using on-line monitoring of EGFP (enhanced green fluorescent protein)-tagged zebrafish Myf5 translocation, we demonstrated that Myf5-EGFP protein resided in the nucleoplasm and nucleolus of zebrafish fibroblast cell lines (ZEM2S and ZF4), mammalian nonmuscle cell line (COS1), and muscle cell lines (RD and C2C12). In contrast, zebrafish MyoD-EGFP was localized in the nucleus but did not condense in the nucleolus. Using indirect immunofluorescent staining, we determined that zebrafish Myf5 was colocalized with nucleophosmin/B23, a nucleolus protein. Deletion analysis revealed that amino acid residues 60 to 82 (60KRKASTVDRRRAATMRERRRLKK82) of Myf5 were sufficient and necessary for nucleolus targeting. A GST pulldown assay followed by Western analysis showed that nucleolin/C23 could be pulled down specifically by GST-Myf5, but not by GST-MyoD. Based on these findings, we propose that the distinct functions of Myf5 and MyoD may result from their differential binding affinity to nucleolin/C23.
...
PMID:A 23-amino acid motif spanning the basic domain targets zebrafish myogenic regulatory factor myf5 into nucleolus. 1622 96

Renal tubular cells elicit adaptive responses following exposure to nephrotoxins, such as cadmium. One response is the up-regulation of the 32-kDa redox-sensitive protein, heme oxygenase-1. Exposure of renal proximal tubular epithelial cells to 10 mum cadmium demonstrated induction ( approximately 20-fold) of heme oxygenase-1 mRNA and protein. Using a 4.5-kb human heme oxygenase-1 promoter construct, the importance of a previously identified cadmium response element (TGCTAGAT) in HeLa cells was verified in renal epithelial cells. Specific protein-DNA interaction with this sequence was demonstrated using nuclear extracts from cadmium-treated cells. Yeast one-hybrid screen of a human kidney cDNA library resulted in the identification of pescadillo, a unique nucleolar, developmental protein, as an interacting protein with the cadmium response element and was confirmed by chromatin immunoprecipitation in vivo and gel shift assays with purified glutathione S-transferase-pescadillo protein in vitro. The specificity of the DNA-protein interaction was verified by the absence of a binding complex when the core sequence of the cadmium response element was mutated or deleted. In addition, B23/nucleophosmin, another nucleolar protein, did not interact with the cadmium response sequence. Overexpression of pescadillo resulted in increased activity of the 4.5-kb human heme oxygenase-1 promoter construct but failed to activate this construct when the cadmium response sequence was mutated. The findings demonstrate the important and previously unrecognized role of pescadillo as a DNA-binding protein interacting specifically with the cadmium response element of the human heme oxygenase-1 gene.
...
PMID:Pescadillo interacts with the cadmium response element of the human heme oxygenase-1 promoter in renal epithelial cells. 1681 89

Toxoplasma gondii GRA10 expressed as a GFP-GRA10 fusion protein in HeLa cells moved to the nucleoli within the nucleus rapidly and entirely. GRA10 was concentrated specifically in the dense fibrillar component of the nucleolus morphologically by the overlap of GFP-GRA10 transfection image with IFA images by monoclonal antibodies against GRA10 (Tg378), B23 (nucleophosmin) and C23 (nucleolin). The nucleolar translocalization of GRA10 was caused by a putative nucleolar localizing sequence (NoLS) of GRA10. Interaction of GRA10 with TATA-binding protein associated factor 1B (TAF1B) in the yeast two-hybrid technique was confirmed by GST pull-down assay and immunoprecipitation assay. GRA10 and TAF1B were also co-localized in the nucleolus after co-transfection. The nucleolar condensation of GRA10 was affected by actinomycin D. Expressed GFP-GRA10 was evenly distributed over the nucleoplasm and the nucleolar locations remained as hollows in the nucleoplasm under a low dose of actinomycin D. Nucleolar localizing and interacting of GRA10 with TAF1B suggested the participation of GRA10 in rRNA synthesis of host cells to favor the parasitism of T. gondii.
...
PMID:Nucleolar translocalization of GRA10 of Toxoplasma gondii transfectionally expressed in HeLa cells. 1787 61

The human myeloid leukemia factor 1 (hMLF1) gene was first identified as an NPM-hMLF1 fusion gene produced by chromosomal translocation. In Drosophila, dMLF has been identified as a protein homologous to hMLF1 and hMLF2, which interacts with various factors involved in transcriptional regulation. However, the precise cellular function of dMLF remains unclear. To generate further insights, we first examined the behavior of dMLF protein using an antibody specific to dMLF. Immunostaining analyses showed that dMLF localizes in the nucleus in early embryos and cultured cells. Ectopic expression of dMLF in the developing eye imaginal disc using eyeless-GAL4 driver resulted in a small-eye phenotype and co-expression of cyclin E rescued the small-eye phenotype, suggesting the involvement of dMLF in cell-cycle regulation. We therefore analyzed the molecular mechanism of interactions between dMLF and a dMLF-interacting protein, dCSN3, a subunit of the COP9 signalosome, which regulates multiple signaling and cell-cycle pathways. Biochemical and genetic analyses revealed that dMLF interacts with dCSN3 in vivo and glutathione S-transferase pull-down assays revealed that the PCI domain of the dCSN3 protein is sufficient for this to occur, possibly functioning as a structural scaffold for assembly of the COP9 signalosome complex. From these data we propose the possibility that dMLF plays a negative role in assembly of the COP9 signalosome complex.
...
PMID:The myeloid leukemia factor interacts with COP9 signalosome subunit 3 in Drosophila melanogaster. 1819 88

The human TESTIN (TES) is a putative tumor suppressor and localizes to the cytoplasm as a component of focal adhesions and cell contacts. TES contains a PET domain in the NH(2)-terminus and three tandem LIM domains in the COOH-terminus. It has been hypothesized that interactions between two termini of TES might lead to a "closed" conformational state of the protein. Here, we provide evidence for different conformational states of TES. We confirmed that the NH(2)-terminus of TES can interact with its third LIM domain in the COOH-terminus by GST pull-down assays. In addition, antisera against the full-length or two truncations of TES were prepared to examine the relationship between the conformation and cellular distribution of the protein. We found that these antisera recognize different regions of TES and showed that TES is co-localised with the marker protein B23 in nucleolus, in addition to its localization in endoplasmic reticulum (ER). Furthermore, our co-immunoprecipitation (co-IP) analysis of TES and B23 demonstrated their co-existence in the same complex. Taken together, our results suggest that TES has different conformational states in different cellular compartments, and a "closed" conformational state of TES may be involved in nucleolar localization.
...
PMID:LIM domain protein TES changes its conformational states in different cellular compartments. 1869 17

The cyclin-dependent kinase inhibitor p21(WAF1/CIP1) is a critical regulator of cell cycle, and it is easily degraded by proteasome through ubiquitin-dependent and -independent pathway. The mechanism of the post-translational regulation of p21 stability remains to be further clarified. In the present study, we have identified nucleophosmin (NPM)/B23, a multifunctional protein that bound p21 and contributed to its stability. The direct interaction between p21 and NPM was confirmed by reciprocal co-immunoprecipitation and GST pull-down assay. Confocal microscopy showed that NPM partially co-localized with p21 in nucleoplasm and their co-localization increased treated with Act D which induces the nucleoplasmic translocation of NPM. We observed the half life of p21 was prolonged with overexpression of NPM or Act D treatment. Knockdown of NPM by siRNA resulted in downregulation of p21 and impaired upregulation of p21 treated with Act D. Further, we examined the effect of NPM expression on the ubiquitination of p21. Overexpression of NPM inhibited the ubiquitination of p21, and depletion of NPM remarkably improved the ubiquitination of p21. Altogether, we provide evidence for a direct binding between NPM and p21, and assign NPM as a positive post-translational regulator of p21.
...
PMID:Nucleophosmin/B23 interacts with p21WAF1/CIP1 and contributes to its stability. 1922 6

Abnormal expression of constitutively active anaplastic lymphoma kinase (ALK) chimeric proteins in the pathogenesis of anaplastic large-cell lymphoma (ALCL) is well established. Recent studies with small molecule kinase inhibitors have provided solid proof-of-concept validation that inhibition of ALK is sufficient to attenuate the growth and proliferation of ALK (+) ALCL cells. In this study, several missense mutants of ALK in the phosphate anchor and gatekeeper regions were generated and their kinase activity was measured. NPM-ALK L182M, L182V, and L256M mutants displayed kinase activity in cells comparable to or higher than that of NPM-ALK wild type (WT) and rendered BaF3 cells into IL-3-independent growth, while NPM-ALK L182R, L256R, L256V, L256P, and L256Q displayed much weaker or little kinase activity in cells. Similar kinase activities were obtained with corresponding GST-ALK mutants with in vitro kinase assays. With regard to inhibitor response, NPM-ALK L182M and L182V exhibited sensitivity to a fused pyrrolocarbazole (FP)-derived ALK inhibitor comparable to that of NPM-ALK WT but were dramatically less sensitive to a diaminopyrimidine (DAP)-derived ALK inhibitor. On the other hand, NPM-ALK L256M exhibited >30-fold lower sensitivity to both FP-derived and DAP-derived ALK inhibitors. The growth inhibition and cytotoxicity of BaF3/NPM-ALK mutant cells induced by ALK inhibitors were consistent with inhibition of cellular NPM-ALK autophosphorylation. In a mouse survival model, treatment with the orally bioavailable DAP-ALK inhibitor substantially extended the survival of the mice inoculated with BaF3/NPM-ALK WT cells but not those inoculated with BaF3/NPM-ALK L256M cells. Binding of ALK inhibitors to ALK WT and mutants was analyzed using ALK homology models. In summary, several potential active ALK mutants were identified, and our data indicate that some of these mutants are resistant to select small molecule ALK inhibitors. Further characterization of these mutants may help to identify and develop potent ALK inhibitors active against both WT and resistant mutants of ALK.
...
PMID:ALK mutants in the kinase domain exhibit altered kinase activity and differential sensitivity to small molecule ALK inhibitors. 1924 73


1 2 Next >>

---