Disease relevance of Ligation

• RESULTS: Of the 89 patients, 82 of whom had cirrhosis of the liver, 44 received propranolol and 45 underwent variceal ligation [1].
• In the smaller infants indomethacin therapy was associated with a significantly lower incidence of major shunts, fewer surgical ligations, a decreased duration of oxygen therapy, and fewer days necessary to regain birth weight [2].
• As HIV-1 also enhances Fas expression on virally infected cells, it is unclear how these hosts avoid rapid cell-autonomous apoptosis mediated through cis ligation of Fas by FasL [3].
• Bis-methionine axial ligation of haem in bacterioferritin from Pseudomonas aeruginosa [4].
• Here, we report that transfer of the gene encoding second mitochondria-derived activator of caspase (Smac) or Smac peptides sensitized various tumor cells in vitro and malignant glioma cells in vivo for apoptosis induced by death-receptor ligation or cytotoxic drugs [5].

High impact information on Ligation

• Whether B-1a (CD5+) cells are a distinct lineage derived from committed fetal/neonatal precursors or arise from follicular B-2 cells in response to BCR ligation and other, unknown signals remains controversial [6].
• T lymphocytes also require activation of tyrosine kinases following T cell receptor (TCR) ligation for maximal stimulation [7].
• CD2 ligation can mediate or enhance T-cell activation, suggesting that signals from CD2/LFA-3 adhesive interactions are integrated with signals from the T-cell antigen receptor during immunological recognition [8].
• The RNA terminated region is displaced into a 5' single-stranded flap, which is removed by the structure-specific flap endonuclease 1 (FEN1), leaving a nick for ligation [9].
• This review summarizes current efforts to obtain homogeneous glycopeptide and glycoprotein materials by a variety of methods that draw from the techniques of recombinant expression, chemical synthesis, enzymatic transformation, and chemoselective ligation [10].

Chemical compound and disease context of Ligation

• RESULTS: We report that the hepatitis C envelope protein E2 can dramatically inhibit T-lymphocyte motility and chemokine release induced via LFA-1 integrin ligation [11].
• Cholestasis produced by bile duct ligation and intraperitoneal injection of D-galactosamine remarkably lowered the Ap4A level to 20% and 42%, respectively; however, the adenosine triphosphate level was only slightly decreased to 65% and 78%, respectively [12].
• CONCLUSIONS: Captopril significantly attenuates the progression of hepatic fibrosis in the rat bile duct ligation model, and its effectiveness should be studied in human chronic liver diseases associated with progressive fibrosis [13].
• Prospective randomised study of effect of octreotide on rebleeding from oesophageal varices after endoscopic ligation [14].
• In a randomised controlled trial, preterm babies undergoing ligation of a patent ductus arteriosus were given nitrous oxide and d-tubocurarine, with (n = 8) or without (n = 8) fentanyl (10 micrograms/kg intravenously) to the anaesthetic regimen [15].

Biological context of Ligation

• Intracellular signal transduction following the extracellular ligation of a wide variety of different types of surface molecules on leukocytes involves the activation of protein tyrosine kinases [16].
• Selection experiments have also been carried out to identify ribozymes that catalyze a variety of chemical transformations, including RNA cleavage, ligation, and synthesis, as well as alkylation and acyl-transfer reactions and N-glycosidic and peptide bond formation [17].
• The reactions that were characterized included the precise excision of the IVS, attachment of guanosine to the 5' end of the IVS, covalent cyclization of the IVS and ligation of the exons [18].
• Mutagenesis and dominant-negative inhibition studies reveal that Shc is necessary and sufficient for activation of the MAP kinase pathway in response to integrin ligation [19].
• A detailed examination of the Drosophila Sex-lethal gene has led to two significant discoveries-the role of the splicing factor SPF45 in defining the site of exon ligation, and that alternative splicing can be regulated at the second step [20].

Anatomical context of Ligation

• We demonstrate therefore that ligation of integrin alpha v beta 3 is required for the survival and maturation of newly forming blood vessels, an event essential for the proliferation of tumors [21].
• Excision of introns from nuclear precursors to messenger RNAs (pre-mRNAs) by the spliceosome requires two distinct phosphodiester transfer (transesterification) reactions: exchange of a 3'-5' for a 2'-5' bond in the first step (lariat formation) and exchange of one 3'-5' phosphodiester for another in the second step (exon ligation) [22].
• In B-cell lines derived from c-rel-/- mice, which like primary cells lacking Rel undergo apoptosis in response to antigen receptor ligation, constitutive expression of an A1 transgene inhibits this pathway to cell death [23].
• More dramatically, SLP-76-/- neutrophils fail to produce ROI, spread, or activate critical downstream regulators in response to integrin ligation [24].
• We show here that treatment of infected macrophages with ATP leads to killing of chlamydiae through ligation of the purinergic receptor, P2X(7)R [25].

Associations of Ligation with chemical compounds

• The best-characterized B12-dependent mutases that catalyze carbon skeleton rearrangement, for which methylmalonyl-coenzyme A mutase is the prototype, also bind cobalamin cofactors with histidine as the cobalt ligand, although other cobalamin-dependent mutases do not appear to utilize histidine ligation [26].
• There were no serious complications of variceal ligation; in the propranolol group, treatment was stopped in two patients because of side effects [1].
• Endoscopic ligation compared with combined treatment with nadolol and isosorbide mononitrate to prevent recurrent variceal bleeding [27].
• Eleven infants in the furosemide group and seven in the chlorothiazide group required ductal ligation (P greater than 0.2) [28].
• One member of this intron class (aI5c in the gene for cytochrome c oxidase subunit I) is capable of self-splicing in vitro, giving correct exon-exon ligation and resulting in the appearance of both linear and lariat forms of the excised intron [29].

Gene context of Ligation

• Arthrin reacts with an anti-ubiquitin antibody, which demonstrates that its extra mass results from ubiquitin ligation [30].
• Upon exon ligation, association of RNPS1, UAP56, and SRm160 is destabilized [31].
• Here, we demonstrate that beta1 integrin ligation on human NK cells results in the activation of the p38 MAPK signaling pathway, which is required for integrin-triggered IL-8 production [32].
• A striking defect in early IL-4 production was observed after ligation of the TCR complex by treatment with anti-CD3 in vivo [33].
• These differences suggest that another adapter must exist that can mediate MyD88-independent signaling in response to TLR4 ligation [34].

Analytical, diagnostic and therapeutic context of Ligation

• In this study, using affinity chromatography, peptide mass fingerprinting and fluorescence resonance energy transfer, we have identified four new proteins that form an activation cluster after LPS ligation and are involved in LPS signal transduction [35].
• Expression of IL-12Rbeta2 alone, however, was insufficient to induce signal transducer and activator of transcription (Stat)4 activation in response to IL-12, whereas IFN-alpha/IFN-alphaR ligation resulted in Stat4 activation in both control and IL-12Rbeta1-deficient cells [36].
• However, no changes in NAD+ hydrolysis or cADPR and ADPR production after CD38 ligation were found by high-performance liquid chromatography; addition of NAD+, ADPR, or cADPR to cultures of lymphoid progenitors did not offset the inhibitory effects of anti-CD38 [37].
• Consequently, the effects of two different types of dilators, nitroglycerin (TNG) and dipyridamole, were studied with radioactive microspheres in open-chested dogs after coronary artery ligation [38].
• We show that Notch ligation in the mature immune system markedly decreases responses to transplantation antigens [39].

References