Sodium Channel β1 Subunit-mediated Modulation of Nav1.2 Currents and Cell Surface Density Is Dependent on Interactions with Contactin and Ankyrin

Nav1.5 voltage-dependent sodium channel regulation involves interactions with partner proteins. In the present paper we report Nav1.5 association with dynamitin, a member of the microtubule-associated dynactin complex whose disruption affects the channel cell-surface density.

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Faculty Opinions recommendation of Epithelial sodium channel regulation by cell surface-associated serum- and glucocorticoid-regulated kinase 1.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.12953956.14257054 ◽

2011 ◽

Author(s):

Bellamkonda Kishore

Keyword(s):

Cell Surface ◽

Sodium Channel ◽

Epithelial Sodium Channel ◽

Channel Regulation

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Slow Human Immunodeficiency Virus (HIV) Infectivity Correlated with Low HIV Coreceptor Levels

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.8.5.932-936.2001 ◽

2001 ◽

Vol 8 (5) ◽

pp. 932-936 ◽

Cited By ~ 3

Author(s):

Cynthia L. Bristow

Keyword(s):

Human Immunodeficiency Virus ◽

Cell Surface ◽

Chemokine Receptors ◽

Surface Density ◽

Human Leukocyte ◽

Absolute Number ◽

Mononuclear Phagocytes ◽

Leukocyte Elastase ◽

Immunodeficiency Virus

ABSTRACT The absolute number of CD4+ lymphocytes in blood is prognostic for disease progression, yet the cell surface density of CD4 receptors or chemokine receptors on a single cell has not previously been found to be predictive of human immunodeficiency virus (HIV) infectivity outcome. It has recently been shown that human leukocyte elastase (HLE) and its ligand α1 proteinase inhibitor (α1PI; α1 antitrypsin) act as HIV fusion cofactors. The present study shows that decreased HIV infectivity is significantly correlated with decreased cell surface density of HLE but not with decreased CD4 nor chemokine receptors. In vitro HIV infectivity outcome in this study was predicted by the surface density of HLE on mononuclear phagocytes but not on lymphocytes. The set point HLE surface density was in part determined by α1PI. Decreased circulating α1PI was correlated with increased cell surface HLE and with increased HIV infectivity. The correlation of HIV infectivity outcome with surface HLE and circulating α1PI supports the utility of these HIV cofactors in diagnostic analysis and therapeutic intervention.

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A generic cell surface ligand system for studying cell-cell recognition

10.1101/546846 ◽

2019 ◽

Author(s):

Eleanor M Denham ◽

Michael I Barton ◽

Susannah M Black ◽

Marcus J Bridge ◽

Ben de Wet ◽

...

Keyword(s):

Cell Surface ◽

Surface Density ◽

Cell Receptor ◽

Surface Receptors ◽

Ligand System ◽

Ligand Interactions ◽

A Cell ◽

Surface Ligand ◽

Receptor Biology ◽

Cell Cell

AbstractDose-response experiments are a mainstay of receptor biology studies and can reveal valuable insights into receptor function. Such studies of receptors that bind cell surface ligands are currently limited by the difficulty in manipulating the surface density of ligands at a cell-cell interface. Here we describe a generic cell surface ligand system that allows precise manipulation of cell surface ligand densities over several orders of magnitude. We validate the system for a range of immunoreceptors, including the T cell receptor (TCR), and show that this generic ligand stimulates via the TCR at a similar surface density as its native ligand. This system allows the effect of surface density, valency, dimensions, and affinity of the ligand to be manipulated. It can be readily extended to other receptor-cell surface ligand interactions, and will facilitate investigation into the activation of, and signal integration between, cell surface receptors.

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Functional interaction of COMMD3 and COMMD9 with the epithelial sodium channel

AJP Renal Physiology ◽

10.1152/ajprenal.00158.2013 ◽

2013 ◽

Vol 305 (1) ◽

pp. F80-F89 ◽

Cited By ~ 12

Author(s):

Yong Feng Liu ◽

Marianne Swart ◽

Ying Ke ◽

Kevin Ly ◽

Fiona J. McDonald

Keyword(s):

Cell Surface ◽

Sodium Channel ◽

Collecting Duct ◽

Extracellular Fluid ◽

Copper Metabolism ◽

Epithelial Sodium Channel ◽

Surface Expression ◽

Cell Surface Expression ◽

Endogenous Regulators ◽

Collecting Duct Cells

The epithelial sodium channel (ENaC) plays an important role in controlling Na+ homeostasis, extracellular fluid volume, and blood pressure. Copper metabolism Murr1 domain-containing protein 1 (COMMD1) interacts with ENaC and downregulates ENaC. COMMD1 belongs to the COMMD family consisting of COMMD1–10, and all COMMD family members share a C-terminal COMM domain. Here, we report that COMMD2–10 also interacts with ENaC, and COMMD3 and COMMD9 were selected for further study. Amiloride-sensitive current in mammalian epithelia expressing ENaC was significantly reduced by COMMD3 or COMMD9, and ENaC expression at the cell surface was significantly decreased in the presence of COMMD3 or COMMD9. COMMD3 and COMMD9 retained their ability to reduce current when COMMD1 was knocked down. COMMD3 and COMMD9 were widely expressed in kidney and were colocalized with ENaC in renal collecting duct cells. These data suggest that COMMD3 and COMMD9 may be endogenous regulators of ENaC to regulate Na+ transport through altering ENaC cell surface expression.

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