Characterization of a Newly Identified Mycobacterial Tautomerase with Promiscuous Dehalogenase and Hydratase Activities Reveals a Functional Link to a Recently Divergedcis-3-Chloroacrylic Acid Dehalogenase

Biochemistry ◽  
2011 ◽  
Vol 50 (14) ◽  
pp. 2889-2899 ◽  
Author(s):  
Bert-Jan Baas ◽  
Ellen Zandvoort ◽  
Anna A. Wasiel ◽  
Wim J. Quax ◽  
Gerrit J. Poelarends
Keyword(s):  
Functional Link ◽  
Chloroacrylic Acid Dehalogenase

scholarly journals DYC-1, a Protein Functionally Linked to Dystrophin in Caenorhabditis elegans Is Associated with the Dense Body, Where It Interacts with the Muscle LIM Domain Protein ZYX-1

2008 ◽  
Vol 19 (3) ◽  
pp. 785-796 ◽  
Author(s):  
Claire Lecroisey ◽  
Edwige Martin ◽  
Marie-Christine Mariol ◽  
Laure Granger ◽  
Yannick Schwab ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Dense Body ◽  
Striated Muscles ◽  
Lim Domain ◽  
Functional Link ◽  
C Elegans ◽  
Lim Domain Protein ◽  
Muscle Necrosis ◽  
Domain Protein

In Caenorhabditis elegans, mutations of the dystrophin homologue, dys-1, produce a peculiar behavioral phenotype (hyperactivity and a tendency to hypercontract). In a sensitized genetic background, dys-1 mutations also lead to muscle necrosis. The dyc-1 gene was previously identified in a genetic screen because its mutation leads to the same phenotype as dys-1, suggesting that the two genes are functionally linked. Here, we report the detailed characterization of the dyc-1 gene. dyc-1 encodes two isoforms, which are expressed in neurons and muscles. Isoform-specific RNAi experiments show that the absence of the muscle isoform, and not that of the neuronal isoform, is responsible for the dyc-1 mutant phenotype. In the sarcomere, the DYC-1 protein is localized at the edges of the dense body, the nematode muscle adhesion structure where actin filaments are anchored and linked to the sarcolemma. In yeast two-hybrid assays, DYC-1 interacts with ZYX-1, the homologue of the vertebrate focal adhesion LIM domain protein zyxin. ZYX-1 localizes at dense bodies and M-lines as well as in the nucleus of C. elegans striated muscles. The DYC-1 protein possesses a highly conserved 19 amino acid sequence, which is involved in the interaction with ZYX-1 and which is sufficient for addressing DYC-1 to the dense body. Altogether our findings indicate that DYC-1 may be involved in dense body function and stability. This, taken together with the functional link between the C. elegans DYC-1 and DYS-1 proteins, furthermore suggests a requirement of dystrophin function at this structure. As the dense body shares functional similarity with both the vertebrate Z-disk and the costamere, we therefore postulate that disruption of muscle cell adhesion structures might be the primary event of muscle degeneration occurring in the absence of dystrophin, in C. elegans as well as vertebrates.

scholarly journals Identification and Characterization of Cor33p, a Novel Protein Implicated in Tolerance towards Oxidative Stress in Candida albicans

2005 ◽  
Vol 4 (12) ◽  
pp. 2160-2169 ◽  
Author(s):  
K. Sohn ◽  
M. Roehm ◽  
C. Urban ◽  
N. Saunders ◽  
D. Rothenstein ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Candida Albicans ◽  
Wild Type ◽  
Two Dimensional Gel Electrophoresis ◽  
Functional Link ◽  
Yeast Peptone Dextrose ◽  
Downstream Effectors ◽  
Benzylic Ether

ABSTRACT We applied two-dimensional gel electrophoresis to identify downstream effectors of CPH1 and EFG1 under hypha-inducing conditions in Candida albicans. Among the proteins that were expressed in wild-type cells but were strongly downregulated in a cph1Δ/efg1Δ double mutant in α-minimal essential medium at 37°C, we could identify not-yet-characterized proteins, including Cor33-1p and Cor33-2p. The two proteins are almost identical (97% identity) and represent products of allelic isoforms of the same gene. Cor33p is highly similar to Cip1p from Candida sp. but lacks any significant homology to proteins from Saccharomyces cerevisiae. Strikingly, both proteins share homology with phenylcoumaran benzylic ether reductases and isoflavone reductases from plants. For other hypha-inducing media, like yeast-peptone-dextrose (YPD) plus serum at 37°C, we could not detect any transcription for COR33 in wild-type cells, indicating that Cor33p is not hypha specific. In contrast, we found a strong induction for COR33 when cells were treated with 5 mM hydrogen peroxide. However, under oxidative conditions, transcription of COR33 was not dependent on EFG1, indicating that other regulatory factors are involved. In fact, upregulation depends on CAP1 at least, as transcript levels were clearly reduced in a Δcap1 mutant strain under oxidative conditions. Unlike in wild-type cells, transcription of COR33 in a tsa1Δ mutant can be induced by treatment with 0.1 mM hydrogen peroxide. This suggests a functional link between COR33 and thiol-specific antioxidant-like proteins that are important in the oxidative-stress response in yeasts. Concordantly, cor33Δ deletion mutants show retarded growth on YPD plates supplemented with hydrogen peroxide, indicating that COR33 in general is implicated in conferring tolerance toward oxidative stress on Candida albicans.

Fungal Peptide Elicitors: Signals Mediating Pathogen Recognition in Plants

1998 ◽  
Vol 53 (3-4) ◽  
pp. 141-150 ◽  
Author(s):  
Thorsten Nürnberger ◽  
Dirk Nennstiel
Keyword(s):  
Plant Defense ◽  
Binding Sites ◽  
Plasma Membranes ◽  
Pathogen Resistance ◽  
Microbial Pathogens ◽  
Functional Link ◽  
High Affinity ◽  
Highly Sensitive ◽  
Recognition Systems

Abstract Highly sensitive and specific recognition systems for microbial pathogens are essential for disease resistance in plants. Proteinaceous elicitors activating plant pathogen defense have been identified in numerous antagonistic plant/fungus interactions. Precisely defined signal structures required for elicitor-mediated activation of plant defense are indicative of the involvement of receptors in elicitor perception and subsequent signal generation. Use of pure elicitor preparations has helped to establish a functional link between binding of elicitors to high-affinity binding sites in plant plasma membranes and activation of plant defense. Thus elicitor binding sites appear to function as physiological receptors. Currently, isolation and molecular characterization of elicitor receptors is under way. Transfer of new recognition specificities into plants is supposed to be a key strategy for engineering pathogen resistance in economically important crops.

scholarly journals The infantile myofibromatosis NOTCH3 L1519P mutation leads to hyperactivated ligand-independent Notch signaling and increased PDGFRB expression

2021 ◽  
Vol 14 (2) ◽  
pp. dmm046300
Author(s):  
Dan Wu ◽  
Sailan Wang ◽  
Daniel V. Oliveira ◽  
Francesca Del Gaudio ◽  
Michael Vanlandewijck ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Extracellular Domain ◽  
Infantile Myofibromatosis ◽  
Independent Manner ◽  
Functional Link ◽  
Downstream Signaling ◽  
Chloroquine Treatment ◽  
Notch3 Mutation ◽  
The Relationship

ABSTRACTInfantile myofibromatosis (IMF) is a benign tumor form characterized by the development of nonmetastatic tumors in skin, bone, muscle and sometimes viscera. Autosomal-dominant forms of IMF are caused by mutations in the PDGFRB gene, but a family carrying a L1519P mutation in the NOTCH3 gene has also recently been identified. In this study, we address the molecular consequences of the NOTCH3L1519P mutation and the relationship between Notch and PDGFRB signaling in IMF. The NOTCH3L1519P receptor generates enhanced downstream signaling in a ligand-independent manner. Despite the enhanced signaling, the NOTCH3L1519P receptor is absent from the cell surface and instead accumulates in the endoplasmic reticulum. Furthermore, the localization of the NOTCH3L1519P receptor in the bipartite, heterodimeric state is altered, combined with avid secretion of the mutated extracellular domain from the cell. Chloroquine treatment strongly reduces the amount of secreted NOTCH3L1519P extracellular domain and decreases signaling. Finally, NOTCH3L1519P upregulates PDGFRB expression in fibroblasts, supporting a functional link between Notch and PDGF dysregulation in IMF. Collectively, our data define a NOTCH3–PDGFRB axis in IMF, in which an IMF-mutated NOTCH3 receptor elevates PDGFRB expression. The functional characterization of a ligand-independent gain-of-function NOTCH3 mutation is important for Notch therapy considerations for IMF, including strategies aimed at altering lysosome function.

scholarly journals Characterization of Cg10062 fromCorynebacterium glutamicum: Implications for the Evolution ofcis-3-Chloroacrylic Acid Dehalogenase Activity in the Tautomerase Superfamily†

Biochemistry ◽  
2008 ◽  
Vol 47 (31) ◽  
pp. 8139-8147 ◽  
Author(s):  
Gerrit J. Poelarends ◽  
Hector Serrano ◽  
Maria D. Person ◽  
William H. Johnson ◽  
Christian P. Whitman
Keyword(s):  
Chloroacrylic Acid Dehalogenase

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

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