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31.
The recognition of DNA double-stranded breaks or single-stranded DNA gaps as a precondition for cell cycle checkpoint arrest has been well established. However, how bulky base damage such as UV-induced pyrimidine dimers elicits a checkpoint response has remained elusive. Nucleotide excision repair represents the main pathway for UV dimer removal that results in strand interruptions. However, we demonstrate here that Rad53p hyperphosphorylation, an early event of checkpoint signaling in Saccharomyces cerevisiae, is independent of nucleotide excision repair (NER), even if replication as a source of secondary DNA damage is excluded. Thus, our data hint at primary base damage or at UV damage (primary or secondary) that does not need to be processed by NER as the relevant substrate of damage-sensing checkpoint proteins. 相似文献
32.
Rhizobium sp. SIN-1, a nitrogen-fixing symbiont of Sesbania aculeata and other tropical legumes, carries two copies of nodD, both on a sym plasmid. We have isolated these two nodD genes by screening a genomic library of Rhizobium sp. SIN-1 with a nodD probe from Sinorhizobium meliloti. Nucleotide sequence and the deduced amino acid sequence analysis indicated that the nodD genes of Rhizobium sp. SIN-1 are most closely related to those of R. tropici and Azorhziobium caulinodans. Rhizobium sp. SIN-1 nodD1 complemented a S. meliloti nodD1D2D3 negative mutant for nodulation on alfalfa, but failed to complement a nodD1 mutant of S. fredii USDA191 for soybean nodulation. A hybrid nodD gene, containing the N-terminus of S. fredii USDA191 nodD1 and the C-terminus of Rhizobium sp. SIN-1 nodD1, complemented the nodD1 negative mutant of USDA191 for nodulation on soybean.
Received: 17 January 2002 / Accepted: 18 February 2002 相似文献
33.
Various mechanicalstimuli increase the intracellular Ca2+ concentration([Ca2+]i) in vascular smooth muscle cells(VSMC). A part of the increase in [Ca2+]i isdue to the release of Ca2+ from intracellular stores. Wehave investigated the effect of mechanical stimulation produced bycyclical stretch on the release of Ca2+ from theintracellular stores. Permeabilized VSMC loaded with 45Ca2+ were subjected to 7.5% average (15%maximal) cyclical stretch. This resulted in an increase in45Ca2+ rate constant by 0.126 ± 0.0035. Inhibition of inositol 1,4,5-trisphosphate (IP3),ryanodine, and nicotinic acid adenine dinucleotide phosphate channels(NAADP) with 50 µg/ml heparin, 50 µM ruthenium red, and 25 µMthio-NADP, respectively, did not block the increase in45Ca2+ efflux in response to cyclical stretch.However, 10 µM lanthanum, 10 µM gadolinium, and 10 µMcytochalasin D but not 10 µM nocodazole inhibited the increase in45Ca2+ efflux. This supports the existence of anovel stretch-sensitive intracellular Ca2+ store in VSMCthat is distinct from the IP3-, ryanodine-, and NAADP-sensitive stores. 相似文献
34.
Jin N Miyahara N Roark CL French JD Aydintug MK Matsuda JL Gapin L O'Brien RL Gelfand EW Born WK 《Journal of immunology (Baltimore, Md. : 1950)》2007,179(5):2961-2968
Mice sensitized and challenged with OVA were used to investigate the role of innate T cells in the development of allergic airway hyperresponsiveness (AHR). AHR, but not eosinophilic airway inflammation, was induced in T cell-deficient mice by small numbers of cotransferred gammadelta T cells and invariant NKT cells, whereas either cell type alone was not effective. Only Vgamma1+Vdelta5+ gammadelta T cells enhanced AHR. Surprisingly, OVA-specific alphabeta T cells were not required, revealing a pathway of AHR development mediated entirely by innate T cells. The data suggest that lymphocytic synergism, which is key to the Ag-specific adaptive immune response, is also intrinsic to T cell-dependent innate responses. 相似文献
35.
Extracting binary signals from microarray time-course data 总被引:1,自引:0,他引:1
This article presents a new method for analyzing microarray time courses by identifying genes that undergo abrupt transitions in expression level, and the time at which the transitions occur. The algorithm matches the sequence of expression levels for each gene against temporal patterns having one or two transitions between two expression levels. The algorithm reports a P-value for the matching pattern of each gene, and a global false discovery rate can also be computed. After matching, genes can be sorted by the direction and time of transitions. Genes can be partitioned into sets based on the direction and time of change for further analysis, such as comparison with Gene Ontology annotations or binding site motifs. The method is evaluated on simulated and actual time-course data. On microarray data for budding yeast, it is shown that the groups of genes that change in similar ways and at similar times have significant and relevant Gene Ontology annotations. 相似文献
36.
Ghosh Chiranjit Patra Debashis Bala Niranjan Majumder Indira Sepay Nayim Mukhopadhyay Prabuddha Das Sukhen Kundu Rita Drew Michael G. B. León Armando Rafael Ghosh Tapas Pradhan Manik 《Biometals》2022,35(3):499-517
BioMetals - A family of dioxidovanadium(V) complexes (1–4) of the type [Na(H2O)x]+[VVO2(HL1?4)]? (x?=?4, 4.5 and 7) where HL2? represents the dianionic form of... 相似文献
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The C‐terminal calcium‐sensitive disordered motifs regulate isoform‐specific polymerization characteristics of calsequestrin
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Naresh C. Bal Nivedita Jena Harapriya Chakravarty Amit Kumar Mei Chi Tuniki Balaraju Sharad V. Rawale Jayashree S. Rawale Ashoke Sharon Muthu Periasamy 《Biopolymers》2015,103(1):15-22
Calsequestrin (CASQ) exists as two distinct isoforms CASQ1 and CASQ2 in all vertebrates. Although the isoforms exhibit unique functional characteristic, the structural basis for the same is yet to be fully defined. Interestingly, the C‐terminal region of the two isoforms exhibit significant differences both in length and amino acid composition; forming Dn‐motif and DEXn‐motif in CASQ1 and CASQ2, respectively. Here, we investigated if the unique C‐terminal motifs possess Ca2+‐sensitivity and affect protein function. Sequence analysis shows that both the Dn‐ and DEXn‐motifs are intrinsically disordered regions (IDRs) of the protein, a feature that is conserved from fish to man. Using purified synthetic peptides, we show that these motifs undergo distinctive Ca2+‐mediated folding suggesting that these disordered motifs are Ca2+‐sensitivity. We generated chimeric proteins by swapping the C‐terminal portions between CASQ1 and CASQ2. Our studies show that the C‐terminal portions do not play significant role in protein folding. An interesting finding of the current study is that the switching of the C‐terminal portion completely reverses the polymerization kinetics. Collectively, these data suggest that these Ca2+‐sensitivity IDRs located at the back‐to‐back dimer interface influence isoform‐specific Ca2+‐dependent polymerization properties of CASQ. © 2014 Wiley Periodicals, Inc. Biopolymers 103: 15–22, 2015. 相似文献
40.
Bodiwala HS Sabde S Gupta P Mukherjee R Kumar R Garg P Bhutani KK Mitra D Singh IP 《Bioorganic & medicinal chemistry》2011,19(3):1256-1263
Designing multi-functional ligands is a recent strategy by which multiple targets can be inhibited by a single entity. A series of caffeoyl-anilide compounds based on structures of various integrase and CCR-5 inhibitors have been designed and synthesized as anti-HIV agents in the present study. Most of the compounds exhibited potent anti-HIV activity at micromolar concentration in CEM-GFP CD4+ T cells infected with HIV-1NL4.3 virus. Compound 14 showed a lower EC(50) and better TI as compared to AZT. Mechanism based studies suggest that these compounds inhibit either one or in some cases, both the targets. The experimental data and the docking results showed that these compounds are potential inhibitors for both HIV-1 IN and CCR5. 相似文献