Search results for "Phosphorylation"
showing 10 items of 975 documents
Redox signaling and histone acetylation in acute pancreatitis
2011
Histone acetylation via CBP/p300 coordinates the expression of proinflammatory cytokines in the activation phase of inflammation, particularly through mitogen-activated protein kinases (MAPKs), nuclear factor-κB (NF-κB), and signal transducers and activators of transcription (STAT) pathways. In contrast, histone deacetylases (HDACs) and protein phosphatases are mainly involved in the attenuation phase of inflammation. The role of reactive oxygen species (ROS) in the inflammatory cascade is much more important than expected. Mitochondrial ROS act as signal-transducing molecules that trigger proinflammatory cytokine production via inflammasome-independent and inflammasome-dependent pathways. …
Biopolyester-based systems containing naturally occurring compounds with enhanced thermooxidative stability
2016
Background This work presents a sustainable approach for the stabilization of polylactic acid (PLA) against thermo-oxidative aging. Methods Naturally occurring phenolic and polyphenolic compounds, such as ferulic acid (FerAc), vanillic acid (VanAc), quercetin (Querc) and vitamin E (VitE), were introduced into PLA. Results The preliminary characterization of the systems formulated containing different amounts of natural stabilizers showed that all compounds used acted as plasticizers, leading to a decrease in rheological functions with respect to neat PLA, without significantly modifying the crystallinity of the raw material. The study of the thermo-oxidative behavior of neat PLA and PLA/nat…
Polo-like kinase 1 as a target for human cytomegalovirus pp65 lower matrix protein
1999
ABSTRACT Human cytomegalovirus (HCMV) pp65 protein is the major constituent of viral dense bodies but is dispensable for viral growth in vitro. pp65 copurifies with a S/T kinase activity and has been implicated in phosphorylation of HCMV IE1 immediate-early protein and its escape from major histocompatibility complex 1 presentation. Furthermore, the presence of pp65 correlates with a virion-associated kinase activity. To clarify the role of pp65, yeast two-hybrid system (THS) screening was performed to identify pp65 cellular partners. A total of 18 out of 48 yeast clones harboring cDNAs for putative pp65 binding proteins encoded the Polo-like kinase 1 (Plk1) C-terminal domain. Plk1 behaved …
Ancistrocyclinones A and B, unprecedented pentacyclic N,C-coupled naphthylisoquinoline alkaloids, from the Chinese liana Ancistrocladus tectorius
2018
Two unique pentacyclic N,C-coupled naphthylisoquinolines, the ancistrocyclinones A (5) and B (6), were discovered in the Chinese liana Ancistrocladus tectorius. Furthermore, six known, likewise N,C-coupled alkaloids, viz., ancistrocladinium A (7a) and its mono- and bisphenolic analogs 8a and 9a were isolated, along with their atropo-diastereomers 7b, 8b, and 9b. The stereostructures of 5 and 6 were determined by HRESIMS, 1D and 2D NMR, oxidative degradation, and ECD calculations. The pentacyclic ancistrocyclinones A (5) and B (6) are structurally similar to berberine alkaloids - yet arising from a most different biosynthetic pathway: they are apparently formed by N,C-coupling of their polyk…
Ubiquitin-independent function of optineurin in autophagic clearance of protein aggregates.
2013
Summary Aggregation of misfolded proteins and the associated loss of neurons are considered a hallmark of numerous neurodegenerative diseases. Optineurin is present in protein inclusions observed in various neurodegenerative diseases including amyotrophic lateral sclerosis (ALS), Huntington's disease, Alzheimer's disease, Parkinson's disease, Creutzfeld-Jacob disease and Pick's disease. Optineurin deletion mutations have also been described in ALS patients. However, the role of optineurin in mechanisms of protein aggregation remains unclear. In this report, we demonstrate that optineurin recognizes various protein aggregates via its C-terminal coiled-coil domain in a ubiquitin-independent m…
Fumarate respiration of Wolinella succinogenes: enzymology, energetics and coupling mechanism.
2002
Wolinella succinogenes performs oxidative phosphorylation with fumarate instead of O2 as terminal electron acceptor and H2 or formate as electron donors. Fumarate reduction by these donors ('fumarate respiration') is catalyzed by an electron transport chain in the bacterial membrane, and is coupled to the generation of an electrochemical proton potential (Deltap) across the bacterial membrane. The experimental evidence concerning the electron transport and its coupling to Deltap generation is reviewed in this article. The electron transport chain consists of fumarate reductase, menaquinone (MK) and either hydrogenase or formate dehydrogenase. Measurements indicate that the Deltap is generat…
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 …
The Elicitor Cryptogein Blocks Glucose Transport in Tobacco Cells
2002
Abstract Cryptogein is a 10-kD protein secreted by the oomycetePhytophthora cryptogea that induces a hypersensitive response on tobacco (Nicotiana tabacum var. Xanthi) plants and a systemic acquired resistance against various pathogens. The mode of action of this elicitor has been studied using tobacco cell suspensions. Our previous data indicated that within minutes, cryptogein signaling involves various events including changes in ion fluxes, protein phosphorylation, sugar metabolism, and, eventually, cell death. These results suggested that transport of sugars could be affected and, thus, involved in the complex relationships between plant and microorganisms via elicitors. This led us to…
Post-translational modifications in the survival motor neuron protein
2004
Spinal muscular atrophy (SMA) is an autosomal recessive disease characterized by a progressive loss of the spinal motoneurons. The SMA-determining gene has been termed survival motor neuron (SMN) and is deleted or mutated in over 98% of patients. The encoded gene product is a protein expressed as different isoforms. In particular, we showed that the rat SMN cDNA produces two isoforms with Mr of 32 and 35 kDa, both localized in nuclear coiled bodies, but the 32 kDa form is also cytoplasmic, whereas the 35 kDa form is also microsomal. To determine the molecular relationship between these two isoforms and potential post-translational modifications, we performed transfection experiments with a …
AML-associated Flt3 kinase domain mutations show signal transduction differences compared with Flt3 ITD mutations
2005
Activating mutations of Flt3 are found in approximately one third of patients with acute myeloid leukemia (AML) and are an attractive drug target. Two classes of Flt3 mutations occur: internal tandem duplications (ITDs) in the juxtamembrane and point mutations in the tyrosine kinase domain (TKD). We and others have shown that Flt3-ITD induced aberrant signaling including strong activation of signal transducer and activator of transcription 5 (STAT5) and repression of CCAAT/estradiol-binding protein α (c/EBPα) and Pu.1. Here, we compared the signaling properties of Flt3-ITD versus Flt3-TKD in myeloid progenitor cells. We demonstrate that Flt3-TKD mutations induced autonomous growth of 32D ce…