Search results for "Receptor complex"

Homodimeric murine interleukin-3 agonists indicate that ligand dimerization is important for high-affinity receptor complex formation.

1994

Homodimeric murine interleukin 3 (mIL-3) agonists were generated by intermolecular cystine-bonding. Steady-state binding assays and association kinetics performed at 4 degrees C using these agonists revealed specific binding to both the high- and low-affinity receptor. DSS-mediated crosslinking studies performed at 4 degrees C with agonist concentrations compatible with high-affinity receptor complex formation allowed to detect protein complexes of the alpha chain, the beta chain(s) and the high-affinity receptor complex migrating with apparent molecular weights of 90 kDa, 140 kDa, and above 180 kDa, respectively. In contrast, monomeric mIL-3 was crosslinked to the alpha chain receptor only…

Enhancement of the FGFR1 signaling in the FGFR1-5-HT1A heteroreceptor complex in midbrain raphe 5-HT neuron systems. Relevance for neuroplasticity an…

2015

New findings show existence of FGFR1-5-HT1A heteroreceptor complexes in 5-HT nerve cells of the dorsal and median raphe nuclei of the rat midbrain and hippocampus. Synergistic receptor-receptor interactions in these receptor complexes indicated their enhancing role in hippocampal plasticity. The existence of FGFR1-5-HT1A heteroreceptor complexes also in midbrain raphe 5-HT nerve cells open up the possibility that antidepressant drugs by increasing extracellular 5-HT levels can cause an activation of the FGF-2/FGFR1 mechanism in these nerve cells as well. Therefore, the agonist modulation of the FGFR1-5-HT1A heteroreceptor complexes and their specific role is now determined in rat medullary …

Fibroblast Growth Factor Receptor 1– 5-Hydroxytryptamine 1A Heteroreceptor Complexes and Their Enhancement of Hippocampal Plasticity

2011

Background The hippocampus and its 5-hydroxytryptamine transmission plays an important role in depression related to its involvement in limbic circuit plasticity. Methods The analysis was made with bioluminescence resonance energy transfer, co-immunoprecipitation, in situ proximity ligation assay, binding assay, in cell western and the forced swim test. Results Using bioluminescence resonance energy transfer analysis, fibroblast growth factor receptor 1 (FGFR1)-5-hydroxytryptamine 1A (5-HT1A) receptor complexes have been demonstrated and their specificity and agonist modulation characterized. Their presence based on co-immunoprecipitation and proximity ligation assay has also been indicated…

Increase of the FGFR1 signaling in the FGFR1-5-HT1A heteroreceptor complex in midbrain raphe 5-HT neuron systems via allosteric receptor-receptor int…

2015

The ascending midbrain 5-HT neurons known to contain 5-HT1A autoreceptors may be dysregulated in depression due to a reduced trophic support. New findings show existence of FGFR1-5-HT1A heteroreceptor complexes in the rat hippocampus with a partial characterization of their interface and in midbrain raphe 5-HT nerve cells. With in situ Proximity Ligation Assay (PLA) and supported by co-location of the FGFR1 and 5-HT1A immunoreactivities in midbrain raphe 5-HT cells, evidence for the existence of FGFR1-5-HT1A heteroreceptor complexes were obtained in the dorsal and median raphe nuclei of the Sprague–Dawley rat. Their existence in the rat medullary raphe RN33B cell cultures was also establish…

The endocytic trafficking pathway of oncogenic papillomaviruses

2019

Over the last two decades many host cell proteins have been described to be involved in the process of infectious entry of oncogenic human papillomaviruses (HPV). After initial binding and priming of the capsid, a sequence of events on the cell surface precedes the formation of the HPV entry platform. It has been shown that the virus-associated entry complex consists of membrane organizers, tetraspanins CD151 and CD63, and their associated partner proteins such as integrins, growth factor receptors, and the annexin A2 heterotetramer. Further recruitment of cytoplasmic factors such as the obscurin-like protein 1 and actin results in a non-canonical clathrin-independent endocytosis of the vir…

The function of the soluble IL-6 receptor in vivo.

1996

Interleukin-6 (IL-6) is considered an important mediator of acute inflammatory responses. Moreover, IL-6 functions as a differentiation and growth factor of hematopoietic precursor cells, B-cells, T-cells, keratinocytes, neuronal cells, osteoclasts and endothelial cells. IL-6 exhibits its action via a receptor complex consisting of a specific IL-6 receptor (IL-6R) and a signal-transducing subunit (gp130). Soluble forms of both receptor components are generated by shedding and are found in patients with various diseases such as AIDS, rheumatoid arthritis and others. The function of the soluble IL-6R in vivo is unknown. To discriminate between the biologic function of hIL-6 alone and that of …

IL-13 receptor α 2: A regulator of IL-13 and IL-4 signal transduction in primary human fibroblasts

2005

Background IL-13 and IL-4 share many functional properties as a result of their use of a common receptor complex comprising IL-13 receptor α 1 (IL-13Rα1) and IL-4 receptor α (IL-4Rα). The nonsignaling receptor IL-13 receptor α 2 (IL-13Rα2) binds IL-13 with high affinity and specificity and is believed to be a decoy receptor for IL-13. Objective We sought to examine the inhibitory effects of soluble and membrane-bound IL-13Rα2 on IL-13– and IL-4–mediated effects. Methods Primary human fibroblasts were grown from endobronchial biopsy specimens obtained from volunteers. Upregulation of IL-13Rα2 mRNA was measured by means of RT-PCR, and the level of surface expression was measured by means of F…

2018

Oncogenic human papillomaviruses (HPV) are small DNA viruses that infect keratinocytes. After HPV binding to cell surface receptors, a cascade of molecular interactions mediates the infectious cellular internalization of virus particles. Aside from the virus itself, important molecular players involved in virus entry include the tetraspanin CD151 and the epidermal growth factor receptor (EGFR). To date, it is unknown how these components are coordinated in space and time. Here, we studied plasma membrane dynamics of CD151 and EGFR and the HPV16 capsid during the early phase of infection. We find that the proteinase ADAM17 activates the extracellular signal-regulated kinases (ERK1/2) pathway…

cFLIPL Inhibits Tumor Necrosis Factor-related Apoptosis-inducing Ligand-mediated NF-κB Activation at the Death-inducing Signaling Complex in Human Ke…

2004

Human keratinocytes undergo apoptosis following treatment with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) via surface-expressed TRAIL receptors 1 and 2. In addition, TRAIL triggers nonapoptotic signaling pathways including activation of the transcription factor NF-kappaB, in particular when TRAIL-induced apoptosis is blocked. The intracellular protein cFLIP(L) interferes with TRAIL-induced apoptosis at the death-inducing signaling complex (DISC) in many cell types. To study the role of cFLIP(L) in TRAIL signaling, we established stable HaCaT keratinocyte cell lines expressing varying levels of cFLIP(L). Functional analysis revealed that relative cFLIP(L) levels correlat…

Existence of muscarinic acetylcholine receptor (mAChR) and fibroblast growth factor receptor (FGFR) heteroreceptor complexes and their enhancement of…

2017

Abstract Background Recently, it was demonstrated that G-protein-coupled receptors (GPCRs) can transactivate tyrosine kinase receptors in absence of their ligands. In this work, driven by the observation that mAChRs and fibroblast growth factor receptors (FGFRs) share signalling pathways and regulation of brain functions, it was decided to explore whether mAChRs activation may transactivate FGFRs and, if so, to characterize the related trophic effects in cultured hippocampal neurons. Methods Oxotremorine-M transactivation of FGFRs and related trophic effects were tested in primary hippocampal neurons. Western blotting and in situ proximity ligation assay (PLA) were used to detect FGFR phosp…