Search results for "Mutant"
showing 10 items of 670 documents
Identification and characterization of an ABA-activated MAP kinase cascade in Arabidopsis thaliana.
2015
†These authors contributed equally to the work. Accession numbers Sequence data from this article can be found in Arabidopsis Genome Initiative or GenBank/EMBL databases under the following accession numbers: At1g10210 (MPK1), At1g59580 (MPK2), At2g43790 (MPK6), At2g18170 (MPK7), At1g18150 (MPK8), At4g36450 (MPK14), At5g40440 (MKK3), At2g32510 (MAP3K17) and At1g05100 (MAP3K18). SUMMARY Abscisic acid (ABA) is a major phytohormone involved in important stress-related and developmental plant processes. Recent phosphoproteomic analyses revealed a large set of ABA-triggered phosphoproteins as putative mitogen-activated protein kinase (MAPK) targets, although the evidence for MAPKs involved in AB…
The Late Endosomal Adaptor Molecule p14 (LAMTOR2) Regulates TGFβ1-Mediated Homeostasis of Langerhans Cells
2014
Langerhans cells (LCs), a sub-population of dendritic cells (DCs) in the skin, participate in the regulation of immunity and peripheral tolerance. The adaptor molecule p14 is part of the late endosomal/lysosomal adaptor and mitogen-activated protein kinase and mammalian target of rapamycin (mTOR) activator/regulator (LAMTOR) complex, which mediates the activation of lysosome-associated extracellular signaling regulated kinase (ERK) and the mTOR cascade. In previous work, we demonstrated that CD11c-specific deficiency of p14 disrupts LC homeostasis by affecting the LAMTOR-mediated ERK and mTOR signaling. In this study, we extended our analysis on p14 deficiency specifically in LCs. Langerin-…
Dimerization of the kinase ARAF promotes MAPK pathway activation and cell migration.
2014
The RAF family of kinases mediates RAS signaling, and RAF inhibitors can be effective for treating tumors with BRAF V600E mutant protein. However, RAF inhibitors paradoxically accelerate metastasis in RAS -mutant tumors and become ineffective in BRAF V600E tumors because of reactivation of downstream mitogen-activated protein kinase (MAPK) signaling. We found that the RAF isoform ARAF has an obligatory role in promoting MAPK activity and cell migration in a cell type–dependent manner. Knocking down ARAF prevented the activation of MAPK kinase 1 (MEK1) and extracellular signal–regulated kinase 1 and 2 (ERK1/2) and decreased the number of protrusions from tumor cell spheroids in three-dimensi…
Evolution of osmosensing signal transduction in Metazoa: stress-activated protein kinases p38 and JNK.
2001
Sponges (Porifera) represent the most basal branch of the Metazoa alive today. We show that two central stress-activated protein kinases involved in the osmosensing pathway, p38 mitogen-activated protein kinase (MAPK) and JNK, can complement for the ancestral MAPK Hog1 in the yeast Saccharomyces cerevisiae. S. cerevisiae mutants lacking Hog1 (hog1-Delta 1) have been complemented with the sponge SDJNK and SDp38 genes. Western blotting has revealed that, after transformation, the hog1-Delta 1+ SDJNK(sense) and hog1-Delta 1+ SDp38(sense) clones express the sponge proteins. Functional studies have demonstrated that the complemented clones grow under hyperosmotic conditions (0.6 M NaCl). Further…
Evaluation of acyl coenzyme A oxidase (Aox) isozyme function in the n- alkane-assimilating yeast Yarrowia lipolytica
1999
ABSTRACT We have identified five acyl coenzyme A (CoA) oxidase isozymes (Aox1 through Aox5) in the n -alkane-assimilating yeast Yarrowia lipolytica , encoded by the POX1 through POX5 genes. The physiological function of these oxidases has been investigated by gene disruption. Single, double, triple, and quadruple disruptants were constructed. Global Aox activity was determined as a function of time after induction and of substrate chain length. Single null mutations did not affect growth but affected the chain length preference of acyl-CoA oxidase activity, as evidenced by a chain length specificity for Aox2 and Aox3. Aox2 was shown to be a long-chain acyl-CoA oxidase and Aox3 was found to …
Genetics for Pseudoalteromonas provides tools to manipulate marine bacterial virus PM2
2008
ABSTRACT The genetic manipulation of marine double-stranded DNA (dsDNA) bacteriophage PM2 ( Corticoviridae ) has been limited so far. The isolation of an autonomously replicating DNA element of Pseudoalteromonas haloplanktis TAC125 and construction of a shuttle vector replicating in both Escherichia coli and Pseudoalteromonas enabled us to design a set of conjugative shuttle plasmids encoding tRNA suppressors for amber mutations. Using a host strain carrying a suppressor plasmid allows the introduction and analysis of nonsense mutations in PM2. Here, we describe the isolation and characterization of a suppressor-sensitive PM2 sus2 mutant deficient in the structural protein P10. To infect an…
Structural basis for light control of cell development revealed by crystal structures of a myxobacterial phytochrome
2018
Phytochromes are red-light photoreceptors that were first characterized in plants, with homologs in photosynthetic and non-photosynthetic bacteria known as bacteriophytochromes (BphPs). Upon absorption of light, BphPs interconvert between two states denoted Pr and Pfr with distinct absorption spectra in the red and far-red. They have recently been engineered as enzymatic photoswitches for fluorescent-marker applications in non-invasive tissue imaging of mammals. This article presents cryo- and room-temperature crystal structures of the unusual phytochrome from the non-photosynthetic myxobacterium Stigmatella aurantiaca (SaBphP1) and reveals its role in the fruiting-body formation of this ph…
Histidine kinases mediate differentiation, stress response, and pathogenicity in Magnaporthe oryzae.
2014
The aim of this study is a functional characterization of 10 putative histidine kinases (HIKs)-encoding genes in the phytopathogenic fungus Magnaporthe oryzae. Two HIKs were found to be required for pathogenicity in the fungus. It was found that the mutant strains ΔMohik5 and ΔMohik8 show abnormal conidial morphology and furthermore ΔMohik5 is unable to form appressoria. Both HIKs MoHik5p and MoHik8p appear to be essential for pathogenicity since the mutants fail to infect rice plants. MoSln1p and MoHik1p were previously reported to be components of the HOG pathway in M. oryzae. The ΔMosln1 mutant is more susceptible to salt stress compared to ΔMohik1, whereas ΔMohik1 appears to be stronger…
The Microbiota Promotes Arterial Thrombosis in Low-Density Lipoprotein Receptor-Deficient Mice
2019
Our results demonstrate a functional role for the commensal microbiota in atherothrombosis. In a ferric chloride injury model of the carotid artery, GF C57BL/6J mice had increased occlusion times compared to colonized controls. Interestingly, in late atherosclerosis, HFD-fed GF Ldlr−/− mice had reduced plaque rupture-induced thrombus growth in the carotid artery and diminished ex vivo thrombus formation under arterial flow conditions.
Identification of Novel pro-α2(IX) Collagen Gene Mutations in Two Families with Distinctive Oligo-Epiphyseal Forms of Multiple Epiphyseal Dysplasia
1999
Multiple epiphyseal dysplasia (MED) is a genetically heterogeneous disorder with marked clinical and radiographic variability. Traditionally, the mild "Ribbing" and severe "Fairbank" types have been used to define a broad phenotypic spectrum. Mutations in the gene encoding cartilage oligomeric-matrix protein have been shown to result in several types of MED, whereas mutations in the gene encoding the alpha2 chain of type IX collagen (COL9A2) have so far been found only in two families with the Fairbank type of MED. Type IX collagen is a heterotrimer of pro-alpha chains derived from three distinct genes-COL9A1, COL9A2, and COL9A3. In this article, we describe two families with distinctive ol…