Search results for "Mutant"
showing 10 items of 670 documents
ID: 37
2015
During the early phase of human cytomegalovirus (HCMV) infection, the Interferon- γ -Inducible factor 16 (IFI16) behaves as a pattern recognition receptor (PRR) sensing viral DNA and triggering antiviral cytokine release. Later on, it restricts virus replication by down-regulating expression of viral genes committed to DNA synthesis including UL54 and UL44. These activities are modulated by viral proteins including pUL83, a tegument protein involved in viral evasion. Here, we demonstrate that pUL83 interacts with IFI16 relieving its inhibitory activity on UL54 gene transcription. We also establish that, starting from 48 h post-infection, IFI16 is stabilized and protected from degradation by…
Modification of the major tegument protein pp65 of human cytomegalovirus inhibits virus growth and leads to the enhancement of a protein complex with…
2010
The tegument protein pp65 of human cytomegalovirus (HCMV) is abundant in lytically infected human foreskin fibroblasts (HFF), as well as in virions and subviral dense bodies (DB). Despite this, we showed previously that pp65 is dispensable for growth in HFF. In the process of refining a DB-based vaccine candidate, different HCMV mutants were generated, expressing a dominant HLA-A2-presented peptide of the IE1 protein fused to pp65. One of the mutant viruses (RV-VM1) surprisingly showed marked impairment in virus release from HFF. We hypothesized that analysis of the phenotypic alterations of RV-VM1 would provide insight into the functions of pp65, poorly defined thus far. RV-VM1 infection r…
Gene-Related Protein Surplus Myopathies
2000
Numerous muscular dystrophies, such as dystrophinopathies, sarcoglycanopathies, and emerino- and laminopathies, are marked by the absence or reduction of mutant transsarcolemmal or nuclear proteins. In addition to these recently identified minus-proteinopathies, there are a growing number of plus-proteinopathies among neuromuscular disorders marked by a surplus or excess of endogenous proteins within muscle fibers of different, i.e., nontranssarcolemmal and nonnuclear types. These proteins are often filamentous; for example, desmin and actin accrue in respective desmin-related myopathies, among which are entities marked by mutant desmin, true desminopathies, and actinopathy, the latter ofte…
Differential disease resistance response in the barley necrotic mutant nec1
2010
Abstract Background Although ion fluxes are considered to be an integral part of signal transduction during responses to pathogens, only a few ion channels are known to participate in the plant response to infection. CNGC4 is a disease resistance-related cyclic nucleotide-gated ion channel. Arabidopsis thaliana CNGC4 mutants hlm1 and dnd2 display an impaired hypersensitive response (HR), retarded growth, a constitutively active salicylic acid (SA)-mediated pathogenesis-related response and elevated resistance against bacterial pathogens. Barley CNGC4 shares 67% aa identity with AtCNGC4. The barley mutant nec1 comprising of a frame-shift mutation of CNGC4 displays a necrotic phenotype and co…
Proteinaceous and oligosaccharidic elicitors induce different calcium signatures in the nucleus of tobacco cells.
2005
We previously reported elevated cytosolic calcium levels in tobacco cells in response to elicitors [D. Lecourieux, C. Mazars, N. Pauly, R. Ranjeva, A. Pugin, Analysis and effects of cytosolic free calcium elevations in response to elicitors in Nicotiana plumbaginifolia cells, Plant Cell 14 (2002) 2627-2641]. These data suggested that in response to elicitors, Ca2+, as a second messenger, was involved in both systemic acquired resistance (RSA) and/or hypersensitive response (HR) depending on calcium signature. Here, we used transformed tobacco cells with apoaequorin expressed in the nucleus to monitor changes in free nuclear calcium concentrations ([Ca2+](nuc)) in response to elicitors. Two …
Role of glutathione in plant signaling under biotic stress
2012
International audience; Glutathione (GSH) is a non-protein thiol compound which has been repeatedly reported to play an important role in plant responses during biotic stresses. However, our knowledge of glutathione-related molecular mechanisms underlying plant defense responses still remains limited. We first discovered that the Arabidopsis thaliana phytoalexin deficient 2-1 (pad2-1) mutant was linked to glutathione deficiency since the mutation was identified in the GSH1 gene encoding the first enzyme of glutathione biosynthesis: Glutamate Cysteine Ligase (GCL). Interestingly, this glutathione-deficient mutant pad2-1 also displays a high susceptibility to a wide range of invaders. We rece…
Characterization of a new, nonpathogenic mutant of Botrytis cinerea with impaired plant colonization capacity.
2006
International audience; Botrytis cinerea is a necrotrophic pathogen that attacks more than 200 plant species.Here, the nonpathogenic mutant A336, obtained via insertional mutagenesis, was characterized.Mutant A336 was nonpathogenic on leaves and fruits, on intact and wounded tissue, while still able to penetrate the host plant. It grew normally in vitro on rich media but its conidiation pattern was altered. The mutant did not produce oxalic acid and exhibited a modified regulation of the production of some secreted proteins (acid protease 1 and endopolygalacturonase 1). Culture filtrates of the mutant triggered an important oxidative burst in grapevine ( Vitis vinifera ) suspension cells, a…
A gated material as immunosensor for in-tissue detection of IDH1-R132H mutation in gliomas
2021
[EN] A nanodevice consisted on nanoporous anodic alumina (NAA) supports functionalized with specific and selective antibody-based gatekeepers for the detection of IDH1-R132H mutant enzyme is here reported. Molecular profile and tissue mutations of the tumours (such as IDH1/IDH2 mutations in gliomas) are a great source of information that already make a difference in terms of prognosis and prediction of response to combined therapy. However, standardized methodologies to determine this mutation are time-consuming and cannot provide information before or during surgical intervention, which significantly limits their utility in terms of intraoperative decisionmaking. To solve this limitation, …
The Regulation of Dorsiventral Symmetry in Plants
2000
The higher plant shoots are generally radially symmetrical; leaves produced at the shoot apex are dorsiventral while axillary shoots again show radial symmetry. Recently analyzed mutants in different plants indicate that the proper definition of adaxial and abaxial identities is necessary to generate a leaf margin and dorsiventral symmetry, Two genes important in the regulation of transsectional leaf symmetry are PHANTASTICA (a MYB (Myeloblastosis oncogene)-domain transcription factor) and KNOTTED1-like genes (homeodomain transcription factors). We review these results in light of hypotheses about the evolutionary origin of leaves and discuss similarities of mutant phenotypes to unifacial l…
Histidine residues near the N terminus of staphylococcal alpha-toxin as reporters of regions that are critical for oligomerization and pore formation.
1994
Chemical modification of histidine residues in staphylococcal alpha-toxin leads to loss of functional activity. Site-directed mutants of the toxin in which each of the four histidine residues was replaced by several amino acids were therefore produced. The mutant proteins were purified and characterized. Exchange of H-259 or H-144 was sometimes tolerated without reduction in hemolytic activity. These histidine residues are thus not essential for toxin function. Exchange of H-35 and H-48, however, had marked effects. H-35 mutant toxins bound with high affinity to rabbit erythrocytes but displayed faulty oligomerization and were unable to form pores. H-48 mutant toxins also had severely impai…