Search results for "binding"
showing 10 items of 3896 documents
Calcium-Dependent Assembly of Centrin-G-Protein Complex in Photoreceptor Cells
2002
Photoexcitation of rhodopsin activates a heterotrimeric G-protein cascade leading to cyclic GMP hydrolysis in vertebrate photoreceptors. Light-induced exchanges of the visual G-protein transducin between the outer and inner segment of rod photoreceptors occur through the narrow connecting cilium. Here we demonstrate that transducin colocalizes with the Ca(2+)-binding protein centrin 1 in a specific domain of this cilium. Coimmunoprecipitation, centrifugation, centrin overlay, size exclusion chromatography, and kinetic light-scattering experiments indicate that Ca(2+)-activated centrin 1 binds with high affinity and specificity to transducin. The assembly of centrin-G-protein complex is medi…
Domain-specific Random Mutagenesis in Light Harvesting Chlorophyll a/b Protein (LHCII)
1998
In all photosynthesising organisms the presence of light harvesting complexes greatly enhances the efficiency of photosynthesis. The most abundant of these pigment binding complexes is the major light harvesting complex II (LHCII) of plants, associated with photosystem II. Its structure has largely been resolved to 3.4 A (1) showing light-harvesting chlorophyll a/b-binding protein (LHCP) with 12 chlorophyll (chl) and 2 xantophyll molecules, all non-covalently arranged around the three membrane spanning domains (MSD) and one amphipathic helix of LHCII. The functional significance of many amino acids in this structure is still unclear, particularly in those parts of the complex that are less …
Pharmacogenetic Study of ABCB1 and CYP3A5 Genes During the First Year Following Heart Transplantation Regarding Tacrolimus or Cyclosporine Levels
2011
Pharmacogenetics explains part of the interindividual variability in drug responses. Many published works about the effects of single nucleotide polymorphisms (SNPs) on immunosuppressive drug blood levels present contradictory results. We evaluated the SNPs in ABCB1 (glycoprotein P) and CYP3A5 (metabolic enzyme) genes, seeking correlate them with tacrolimus or cyclosporine levels during the first year after heart transplantation. One blood sample was obtained from each of 41 patients: 26 treated with cyclosporine and 15 with tacrolimus. We characterize the SNPs rs1045642, 1128503, 2032582, 2235013, 2235033, 2229109, 3213619, 9282564 in ABCB1 and rs10264272, 776746 in CYP3A5 genes using the …
Quantification of the Raf-C1 Interaction With Solid-Supported Bilayers
2002
By use of the quartz crystal microbalance technique, the interaction of the Raf-Ras binding domain (RafRBD) and the cysteine-rich domain Raf-C1 with lipids was quantified by using solid-supported bilayers immobilized on gold electrodes deposited on 5 MHz quartz plates. Solid-supported lipid bilayers were composed of an initial octanethiol monolayer chemisorbed on gold and a physisorbed phospholipid monolayer varying in its lipid composition as the outermost layer. The integrity of bilayer preparation was monitored by impedance spectroscopy. For binding experiments, a protein construct comprising the RafRBD and Raf-C1 linked to the maltose binding protein and a His tag, termed MBP-Raf-C1, wa…
All-trans to 11-cis conversion of endogenous retinoids in nuclear membrane preparations from bovine retinal pigment epithelium
1992
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Different origin of adipogenic stem cells influences the response to antiretroviral drugs
2015
Lipodystrophy (LD) is a main side effect of antiretroviral therapy for HIV infection, and can be provoked by nucleoside reverse transcriptase inhibitors (NRTIs) and protease inhibitors (PIs). LD exists in different forms, characterized by fat loss, accumulation, or both, but its pathogenesis is still unclear. In particular, few data exist concerning the effects of antiretroviral drugs on adipocyte differentiation. Adipose tissue can arise either from mesenchymal stem cells (MSCs), that include bone marrow-derived MSCs (hBM-MSCs), or from ectodermal stem cells, that include dental pulp stem cells (hDPSCs). To analyze whether the embryonal origin of adipocytes might impact the occurrence of d…
Pro-invasive stimuli and the interacting protein Hsp70 favour the route of alpha-enolase to the cell surface
2017
AbstractCell surface expression of alpha-enolase, a glycolytic enzyme displaying moonlighting activities, has been shown to contribute to the motility and invasiveness of cancer cells through the protein non-enzymatic function of binding plasminogen and enhancing plasmin formation. Although a few recent records indicate the involvement of protein partners in the localization of alpha-enolase to the plasma membrane, the cellular mechanisms underlying surface exposure remain largely elusive. Searching for novel interactors and signalling pathways, we used low-metastatic breast cancer cells, a doxorubicin-resistant counterpart and a non-tumourigenic mammary epithelial cell line. Here, we demon…
LPS injection reprograms the expression and the 3′ UTR of a CAP gene by alternative polyadenylation and the formation of a GAIT element in Ciona inte…
2016
The diversification of cellular functions is one of the major characteristics of multicellular organisms which allow cells to modulate their gene expression, leading to the formation of transcripts and proteins with different functions and concentrations in response to different stimuli. CAP genes represent a widespread family of proteins belonging to the cysteine-rich secretory protein, antigen 5 and pathogenesis-related 1 superfamily which, it has been proposed, play key roles in the infection process and the modulation of immune responses in host animals. The ascidian Ciona intestinalis represents a group of proto-chordates with an exclusively innate immune system that has been widely st…
Isolation and expression of a novel MBL-like collectin cDNA enhanced by LPS injection in the body wall of the ascidian Ciona intestinalis
2009
Collectins are a family of calcium-dependent lectins that are characterized by their collagen-like domains. Considerable interest has been focused on this class of proteins because of their ability to interact with components of the complement system activating a cascade of events responsible for the activation of the innate immune system. A differential screening between LPS-challenged and naïve Ciona intestinalis has been performed allowing the isolation of a full length cDNA encoding for a 221 AA protein. In silico analysis has shown that this polypeptide displays protein domains with similarities to mannose-binding lectins. A phylogenetic analysis suggested that C. intestinalis MBL has …
New functional ligands for ficolin-3 among lipopolysaccharides of Hafnia alvei.
2011
Ficolin-1 (M), ficolin-2 (L), ficolin-3 (H) and mannan-binding lectin (MBL) activate the complement system and have opsonic activity. The specificity of ficolin-3 is poorly characterized and currently limited to a few ligands only. We present new specific targets for human ficolin-3, identified among lipopolysaccharides (LPSs, endotoxin) of Hafnia alvei. The interaction was restricted to LPSs of four strains: 23, Polish Collection of Microorganisms (PCM) 1200, PCM 1203 and PCM 1205 and limited to their O-specific polysaccharides (O-specific PSs) composed of different numbers of oligosaccharide (OS) repeating units (RUs). Moreover, these LPS/ficolin-3 complexes activated the lectin pathway o…