Search results for "binding proteins"
showing 10 items of 911 documents
Myc Promoter-Binding Protein-1 (MBP-1) Is a Novel Potential Prognostic Marker in Invasive Ductal Breast Carcinoma
2010
BackgroundAlpha-enolase is a glycolytic enzyme that catalyses the formation of phosphoenolpyruvate in the cell cytoplasm. α-Enolase and the predominantly nuclear Myc promoter-binding protein-1 (MBP-1) originate from a single gene through the alternative use of translational starting sites. MBP-1 binds to the P2 c-myc promoter and competes with TATA-box binding protein (TBP) to suppress gene transcription. Although several studies have shown an antiproliferative effect of MBP-1 overexpression on several human cancer cells, to date detailed observations of α-enolase and MBP-1 relative expression in primary tumors versus normal tissues and their correlation with clinicopathological features ha…
Nuclear Translocation of Mismatch Repair Proteins MSH2 and MSH6 as a Response of Cells to Alkylating Agents
2000
Mammalian mismatch repair has been implicated in mismatch correction, the prevention of mutagenesis and cancer, and the induction of genotoxicity and apoptosis. Here, we show that treatment of cells specifically with agents inducing O(6)-methylguanine in DNA, such as N-methyl-N'-nitro-N-nitrosoguanidine and N-methyl-N-nitrosourea, elevates the level of MSH2 and MSH6 and increases GT mismatch binding activity in the nucleus. This inducible response occurs immediately after alkylation, is long-lasting and dose-dependent, and results from translocation of the preformed MutSalpha complex (composed of MSH2 and MSH6) from the cytoplasm into the nucleus. It is not caused by an increase in MSH2 gen…
DNA binding of L1 is required for human papillomavirus morphogenesis in vivo.
2002
AbstractThe role of putative DNA-binding domains of human papillomavirus (HPV) capsid proteins for DNA encapsidation in vivo is still unknown. We have now analyzed mutants of the major capsid protein L1 of HPV type 33, which are defective for DNA binding, for their ability to encapsidate DNA using an in vivo packaging approach. Since the DNA-binding domain and the nuclear localization signal (NLS) of L1 overlap, both a carboxy-terminal deletion mutant (L1-1/470) and a substitution mutant (L1-1/477M9) were analyzed. L1-1/477M9 has the classical NLS replaced by a noncanonical NLS taken from the human hnRNP protein A1. The mutant proteins were defective for DNA binding in contrast to wild-type…
Competitive binding of Rab21 and p120RasGAP to integrins regulates receptor traffic and migration
2011
P120RasGAP competes with Rab21 for binding to the cytoplasmic domain of integrin α-subunits, thereby promoting receptor escape from early endosomes and recycling to the plasma membrane.
Activation and translocation of p38 mitogen-activated protein kinase after stimulation of monocytes with contact sensitizers.
2002
Recently we described the induction of tyrosine phosphorylation by contact sensitizers as an early molecular event during the activation of antigen- presenting cells. In this study, the role of the p38 mitogen-activated protein kinase for the activation of human monocytes after exposure to four structurally unrelated contact sensitizers was analyzed in comparison with the irritant benzalkonium chloride and an inductor of oxidative stress (H 2 O 2 ) using immunofluorescence, Western blotting, and enzyme-linked immunosorbent assay techniques. Bio chemical analysis revealed a translocation of p38 from the cytoplasm to the detergent-resistant cell fraction only upon stimulation with contact sen…
Regulation of ribonucleotide reductase in response to iron deficiency
2011
Ribonucleotide reductase (RNR) is an essential enzyme required for DNA synthesis and repair. Although iron is necessary for class Ia RNR activity, little is known about the mechanisms that control RNR in response to iron deficiency. In this work, we demonstrate that yeast cells control RNR function during iron deficiency by redistributing the Rnr2–Rnr4 small subunit from the nucleus to the cytoplasm. Our data support a Mec1/Rad53-independent mechanism in which the iron-regulated Cth1/Cth2 mRNA-binding proteins specifically interact with the WTM1 mRNA in response to iron scarcity, and promote its degradation. The resulting decrease in the nuclear-anchoring Wtm1 protein levels leads to the re…
The DNA-binding subunit p140 of replication factor C is upregulated in cycling cells and associates with G 1 phase cell cycle regulatory proteins
1999
The DNA-binding subunit of replication factor C (RFCp140) plays an important role in both DNA replication and DNA repair. The mechanisms regulating activation of RFCp140 thereby controlling replication and cellular proliferation are largely unknown. We analyzed protein expression of RFCp140 during cell cycle progression and investigated the association of RFCp140 with cell cycle regulatory proteins in cell lines of various tissue origin and in primary hematopoietic cells. Western and Northern blot analyses of RFCp140 from synchronized cells showed downregulation of RFCp140 when cells enter a G0-like quiescent state and upregulation of RFCp140 in cycling cells. Translocation from the cytopla…
Cell Cycle Activation of the Swi6p Transcription Factor Is Linked to Nucleocytoplasmic Shuttling
2003
The control of the subcellular localization of cell cycle regulators has emerged as a crucial mechanism in the regulation of cell division. In the present work, we have characterized the function of the karyopherin Msn5p in the control of the cell cycle of Saccharomyces cerevisiae. Phenotypic analysis of the msn5 mutant revealed an increase in cell size and a functional interaction between Msn5p and the cell cycle transcription factor SBF (composed of the Swi4p and Swi6p proteins), indicating that Msn5p is involved in Start control. In fact, we have shown that the level of Cln2p protein is drastically reduced in an msn5 mutant. The effect on CLN2 expression is mediated at a transcriptional …
Gene expression is circular: factors for mRNA degradation also foster mRNA synthesis.
2013
SummaryMaintaining proper mRNA levels is a key aspect in the regulation of gene expression. The balance between mRNA synthesis and decay determines these levels. We demonstrate that most yeast mRNAs are degraded by the cytoplasmic 5′-to-3′ pathway (the “decaysome”), as proposed previously. Unexpectedly, the level of these mRNAs is highly robust to perturbations in this major pathway because defects in various decaysome components lead to transcription downregulation. Moreover, these components shuttle between the cytoplasm and the nucleus, in a manner dependent on proper mRNA degradation. In the nucleus, they associate with chromatin—preferentially ∼30 bp upstream of transcription start-sit…
Automatic Counting of Intra-Cellular Ribonucleo-Protein Aggregates in Saccharomyces cerevisiae Using a Textural Approach.
2019
AbstractIn the context of microbiology, recent studies show the importance of ribonucleo-protein aggregates (RNPs) for the understanding of mechanisms involved in cell responses to specific environmental conditions. The assembly and disassembly of aggregates is a dynamic process, the characterization of the stage of their evolution can be performed by the evaluation of their number. The aim of this study is to propose a method to automatically determine the count of RNPs. We show that the determination of a precise count is an issue by itself and hence, we propose three textural approaches: a classical point of view using Haralick features, a frequency point of view with generalized Fourier…