Search results for "DNA-binding domain"
showing 10 items of 13 documents
The C-terminal domain of ParB is critical for dynamic DNA binding and bridging interactions which condense the bacterial centromere
2017
SUMMARYThe ParB protein forms DNA bridging interactions aroundparSto form networks which condense DNA and earmark the bacterial chromosome for segregation. The mechanism underlying the formation of ParB nucleoprotein complexes is unclear. We show here that the central DNA binding domain is essential for anchoring atparS, and that this interaction is not required for DNA condensation. Structural analysis of the C-terminal domain reveals a dimer with a lysine-rich surface that binds DNA non-specifically and is essential for DNA condensationin vitro. Mutation of either the dimerisation or the DNA binding interface eliminates ParB foci formationin vivo. Moreover, the free C-terminal domain can …
Molecular cloning and expression of Tenebrio molitor ultraspiracle during metamorphosis and in vivo induction of its phosphorylation by 20-hydroxyecd…
2000
Using a RT-PCR approach, the Tenebrio molitor homologue of Drosophila Ultraspiracle (TmUSP) was characterized. Its DNA binding domain shows a degree of identity with those of the other insect USPs. However, the ligand binding domain is closer to those of retinoid X receptors. Using an antibody raised against DmUSP, Western blot analysis of proteins from epidermis and other tissues revealed five immunoreactive bands, corresponding to different phosphorylated forms of a unique polypeptide, as shown by lambda-phosphatase treatment. The nuclear form of TmUSP seems unphosphorylated. An in vivo 20-hydroxyecdysone treatment increases considerably and rapidly the phosphorylated forms of TmUSP. This…
Isolation and characterization of five Fox (Forkhead) genes from the sponge Suberites domuncula.
2003
Fox or Forkhead genes constitute a subgroup of the helix-turn-helix class of transcription factors with a characteristic and highly conserved DNA binding domain. To date, around 100 different Fox genes have been reported ranging from yeast to humans; these have been classified into 18 subclasses (A to P). Fox proteins are responsible for a wide range of functions and key roles in early developmental processes, during organogenesis and also for the function of the major organs and tissues in the adult. Here, we report the isolation and phylogenetic characterization of five members of the Fox family from the sponge Suberites domuncula. Four of them (Sd-FoxL2, Sd-FoxP, Sd-FoxD and Sd-FoxF) fal…
Functional analysis of the isoforms of an ABI3-like factor of Pisum sativum generated by alternative splicing
2009
At least seven isoforms (PsABI3-1 to PsABI3-7) of a putative, pea ABI3-like factor, originated by alternative splicing, have been identified after cDNA cloning. A similar variability had previously only been described for monocot genes. The full-length isoform, PsABI3-1, contains the typical N-terminal acidic domains and C-terminal basic subdomains, B1 to B3. Reverse transcriptase-PCR analysis revealed that the gene is expressed just in seeds, starting at middle embryogenesis; no gene products are observed in embryo axes after 18 h post-imbibition although they are more persistent in cotyledons. The activity of the isoforms was studied by yeast one-hybrid assays. When yeast was transformed …
Modulation of base excision repair of 8-oxoguanine by the nucleotide sequence.
2013
8-Oxoguanine (8-oxoG) is a major product of oxidative DNA damage, which induces replication errors and interferes with transcription. By varying the position of single 8-oxoG in a functional gene and manipulating the nucleotide sequence surrounding the lesion, we found that the degree of transcriptional inhibition is independent of the distance from the transcription start or the localization within the transcribed or the non-transcribed DNA strand. However, it is strongly dependent on the sequence context and also proportional to cellular expression of 8-oxoguanine DNA glycosylase (OGG1)-demonstrating that transcriptional arrest does not take place at unrepaired 8-oxoG and proving a causal…
8-Oxo-7,8-dihydroguanine in DNA does not constitute a barrier to transcription, but is converted into transcription-blocking damage by OGG1.
2011
The common DNA base modification 8-oxo-7,8-dihydroguanine (8-oxo-G) affects the efficiency and fidelity of transcription. We constructed plasmid substrates carrying single 8-oxo-G residues, specifically positioned in the transcribed or the non-transcribed DNA strands, to investigate their effects on the expression of an EGFP reporter gene and to explore the role of base excision repair in the mechanism of transcription inhibition. We report that 8-oxo-G does not directly block transcription in cells, since a single 8-oxo-G in the transcribed DNA strand did not reduce the EGFP expression levels in repair-deficient (OGG1-null) mouse embryonic fibroblast cell lines. Rather, inhibition of trans…
TP53 in gastric cancer: mutations in the l3 loop and LSH motif DNA-binding domains of TP53 predict poor outcome.
2004
The aim of this study was to clarify whether specific p53 mutations may have biological relevance in terms of disease relapse or death in gastric carcinomas (GC). Resected specimens from a consecutive series of 62 patients with GC undergoing potentially curative surgery were prospectively studied. The mutational status of exons 5-8 of the p53 gene was investigated in 62 cases using the PCR-SSCP and sequencing. Presence of microsatellite instability (MSI) was evaluated in 56 cases by analyzing loci highly sensitive of MSI. Twenty mutations of p53 were detected in 17 of the 62 cases analyzed (27%). Ten mutations (50%) occurred in highly conserved domains. According to the p53 specific functio…
Characterization of aCandida albicansgene encoding a putative transcriptional factor required for cell wall integrity
2003
After screening a Candida albicans genome database the product of an open reading frame (ORF) (CA2880) with 49% homology to the product of Saccharomyces cerevisiae YPL133c, a putative transcriptional factor, was identified. The disruption of the C. albicans gene leads to a major sensitivity to calcofluor white and Congo red, a minor sensitivity to sodium dodecyl sulfate, a major resistance to zymolyase, and an alteration of the chemical composition of the cell wall. For these reasons we called it CaCWT1 (for C. albicans cell wall transcription factor). CaCwt1p contains a putative Zn(II) Cys(6) DNA binding domain characteristic of some transcriptional factors and a PAS domain. The CaCWT1 gen…
Cyclic AMP-induced Chromatin Changes Support the NFATc-mediated Recruitment of GATA-3 to the Interleukin 5 Promoter
2008
Elevated intracellular cyclic AMP levels, which suppress the proliferation of naive T cells and type 1 T helper (Th1) cells are a property of T helper 2 (Th2) cells and regulatory T cells. While cyclic AMP signals interfere with the IL-2 promoter induction, they support the induction of Th2-type genes, in particular of il-5 gene. We show here that cyclic AMP signals support the generation of three inducible DNase I hypersensitive chromatin sites over the il-5 locus, including its promoter region. In addition, cyclic AMP signals enhance histone H3 acetylation at the IL-5 promoter and the concerted binding of GATA-3 and NFATc to the promoter. This is facilitated by direct protein-protein inte…
The yeast putative transcriptional repressor RGM1 is a proline-rich zinc finger protein.
1991
Abstract I have cloned a yeast gene, RGM1, which encodes a proline-rich zinc, finger protein. rgm1 mutants do not show any obvious phenotype but overexpression of RGM1 gene greatly impairs cell growth. The proline-rich region of RGM1 attached to a heterologous DNA binding domain is able to repress the expression of the target gene. RGM1 shares similar zinc finger motifs with the mammalian Egr (early growth response) proteins as well as proline-rich sequences with a high serine and threonine content, suggesting that RGM1 and Egr proteins could have functional similarities.