Search results for "channels"
showing 10 items of 411 documents
The Xenopus Oocyte as an Ectopic Expression System for the Selection of Protein Isoform-Specific Antibodies
1993
A panel of Xenopus oocytes, each injected with cRNA coding for one specific isoform of the rat brain RCK family of voltage gated potassium channel proteins, was employed to screen for isoform-specific monoclonal antibodies. Several days after injection, cryosections of embedded oocytes were produced and were employed in immunohistochemical analysis of antibody binding. Of the advantageous properties of the assay, it employs the native antigen, it can be applied to homooligomeric and heterooligomeric proteins, and cryosections of the same batch can be stored frozen for later tests. The method may be advantageous also for the selection of isoform-specific antibodies of other protein families.
Application of an ectopic expression system for the selection of protein-isoform-specific antibodies. The monoclonal antibody K1 C3 is specific for t…
1993
Monoclonal antibodies were raised against a fusion protein consisting of a fragment of 141 amino acids of the C-terminal region of the rat brain voltage-gated K(+)-channel protein (RCK1) and the lambda N protein (fusion protein I). Selection of K(+)-channel-specific hybridoma cell lines was performed by means of an ELISA employing a fusion protein consisting of the K(+)-channel-specific peptide sequence and glutathione S-transferase (fusion protein II). For final selection of RCK1 isoform-specific antibodies, a panel of Xenopus oocytes was employed, each injected with cRNA coding for a specific RCK isoform (RCK 1, 2, 4 or 5). Several days after injection, cryosections of embedded oocytes we…
Differential gene expression analysis identifies murine Cacnb3 as strongly upregulated in distinct dendritic cell populations upon stimulation
2011
Langerhans cells (LCs) represent the dendritic cell (DC) population in the epidermis. Among the set of genes induced in primary mouse LCs in response to stimulation, both isoforms of the voltage-dependent Ca²(+) channel (VDCC) regulatory subunit Cacnb3 as well as the DC maturation marker Fscn1 were upregulated most strongly. Comparable results were obtained for a recently described myeloid DC line (SP37A3). Other antigen presenting cell populations, namely, bone marrow-derived DCs, macrophages and primary B cells, showed no stimulation-associated upregulation of Cacnb3 expression. Pharmacological inhibition of Ca²(+) channel activity during the stimulation of SP37A3 cells enhanced their T c…
A Trajectory-Driven 3D Non-Stationary mm-Wave MIMO Channel Model for a Single Moving Point Scatterer
2021
This paper proposes a new non-stationary three-dimensional (3D) channel model for a physical millimeter wave (mm-Wave) multiple-input multiple-output (MIMO) channel. This MIMO channel model is driven by the trajectory of a moving point scatterer, which allows us to investigate the impact of a single moving point scatterer on the propagation characteristics in an indoor environment. Starting from the time-variant (TV) channel transfer function, the temporal behavior of the proposed non-stationary channel model has been analyzed by studying the TV micro-Doppler characteristics and the TV mean Doppler shift. The proposed channel model has been validated by measurements performed in an indoor e…
COVID-19, Cation Dysmetabolism, Sialic Acid, CD147, ACE2, Viroporins, Hepcidin and Ferroptosis: A Possible Unifying Hypothesis.
2022
Background: iron and calcium dysmetabolism, with hyperferritinemia, hypoferremia, hypocalcemia and anemia have been documented in the majority of COVID-19 patients at later/worse stages. Furthermore, complementary to ACE2, both sialic acid (SA) molecules and CD147 proved relevant host receptors for SARS-CoV-2 entry, which explains the viral attack to multiple types of cells, including erythrocytes, endothelium and neural tissue. Several authors advocated that cell ferroptosis may be the core and final cell degenerative mechanism. Methods: a literature research was performed in several scientific search engines, such as PubMed Central, Cochrane Library, Chemical Abstract Service. More than 5…
Calcium binding and ionic conduction in single conical nanopores with polyacid chains: model and experiments.
2012
Calcium binding to fixed charge groups confined over nanoscale regions is relevant to ion equilibrium and transport in the ionic channels of the cell membranes and artificial nanopores. We present an experimental and theoretical description of the dissociation equilibrium and transport in a single conical nanopore functionalized with pH-sensitive carboxylic acid groups and phosphonic acid chains. Different phenomena are simultaneously present in this basic problem of physical and biophysical chemistry: (i) the divalent nature of the phosphonic acid groups fixed to the pore walls and the influence of the pH and calcium on the reversible dissociation equilibrium of these groups; (ii) the asym…
Polycystin-1 downregulation induces ERK-dependent mTOR pathway activation in a cellular model of psoriasis
2018
Psoriatic plaques tend to localize to the knees and elbows, areas that are particularly subject to mechanical stress resulting from bending and friction. Moreover, plaques often develop at sites of mechanical trauma or injury (Koebner phenomenon). Nevertheless, mechanotransduction has never been linked to psoriasis. Polycystins (polycystin-1, PC1; polycystin-2, PC2) are mechanosensitive molecules that function as key regulators of cellular mechanosensitivity and mechanotransduction. The aim of this in vitro study was to investigate the role of polycystins in the development of psoriasis. We showed that PC1 knockdown in HaCaT cells led to an elevated mRNA expression of psoriasis-related biom…
Association of Whirlin with Cav1.3 (α1D) Channels in Photoreceptors, Defining a Novel Member of the Usher Protein Network
2010
Contains fulltext : 88383.pdf (Publisher’s version ) (Closed access) PURPOSE: Usher syndrome is the most common form of hereditary deaf-blindness. It is both clinically and genetically heterogeneous. The USH2D protein whirlin interacts via its PDZ domains with other Usher-associated proteins containing a C-terminal type I PDZ-binding motif. These proteins co-localize with whirlin at the region of the connecting cilium and at the synapse of photoreceptor cells. This study was undertaken to identify novel, Usher syndrome-associated, interacting partners of whirlin and thereby obtain more insights into the function of whirlin. METHODS: The database of ciliary proteins was searched for proteins…
The cGMP-gated channel of the rod photoreceptor — a new type of channel structure?
1990
Recents findings from Numa's laboratory reveal that there might exist a wider variety in channel protein structure than originally anticipated. Recently, the cloning has been reported of the first cGMP-gated ion channel, the vertebrate rod photoreceptor which is activated by cGMP acting from the inside of the rod outer segment membrane
A new actor involved in hypothalamic glucose detection : the Transient Receptor Potential Canonical (TRPC) channels
2015
Hyperglycemia is detected and integrated by the mediobasal hypothalamus (MBH) which, in turn, inhibits food intake and triggers insulin secretion. The MBH houses specialized glucose-sensitive (GS) neurons, which directly or indirectly modulate their electrical activity in response to changes in glucose level. In a first study, we hypothesized that indirect detection of glucose by MBH GS neurons involves the secretion of endozepine by astrocytes, a gliotransmitter known to inhibit food intake in response to hyperglycemia. The present work shows that endozepines selectively activate anorexigenic MBH pro-opiomelanotortine (POMC) neurons. In the second study, we show that the direct detection o…