scholarly journals Modulation of Kv4.2/KChIP3 interaction by the ceroid lipofuscinosis neuronal 3 protein CLN3

2020 ◽  
Vol 295 (34) ◽  
pp. 12099-12110
Author(s):  
Carolin Seifert ◽  
Stephan Storch ◽  
Robert Bähring
Keyword(s):  
Neuronal Ceroid Lipofuscinosis ◽  
Surface Expression ◽  
Lower Amount ◽  
Hek 293 ◽  
Current Decay ◽  
Ceroid Lipofuscinosis ◽  
Kv Channels ◽  
Channel Expression ◽  
Lysosomal Membrane Glycoprotein ◽  
And Function

Voltage-gated potassium (Kv) channels of the Kv4 subfamily associate with Kv channel–interacting proteins (KChIPs), which leads to enhanced surface expression and shapes the inactivation gating of these channels. KChIP3 has been reported to also interact with the late endosomal/lysosomal membrane glycoprotein CLN3 (ceroid lipofuscinosis neuronal 3), which is modified because of gene mutation in juvenile neuronal ceroid lipofuscinosis (JNCL). The present study was undertaken to find out whether and how CLN3, by its interaction with KChIP3, may indirectly modulate Kv4.2 channel expression and function. To this end, we expressed KChIP3 and CLN3, either individually or simultaneously, together with Kv4.2 in HEK 293 cells. We performed co-immunoprecipitation experiments and found a lower amount of KChIP3 bound to Kv4.2 in the presence of CLN3. In whole-cell patch-clamp experiments, we examined the effects of CLN3 co-expression on the KChIP3-mediated modulation of Kv4.2 channels. Simultaneous co-expression of CLN3 and KChIP3 with Kv4.2 resulted in a suppression of the typical KChIP3-mediated modulation; i.e. we observed less increase in current density, less slowing of macroscopic current decay, less acceleration of recovery from inactivation, and a less positively shifted voltage dependence of steady-state inactivation. The suppression of the KChIP3-mediated modulation of Kv4.2 channels was weaker for the JNCL-related missense mutant CLN3R334C and for a JNCL-related C-terminal deletion mutant (CLN3ΔC). Our data support the notion that CLN3 is involved in Kv4.2/KChIP3 somatodendritic A-type channel formation, trafficking, and function, a feature that may be lost in JNCL.

S-acylation regulates Kv1.5 channel surface expression

2007 ◽  
Vol 293 (1) ◽  
pp. C152-C161 ◽  
Author(s):  
Lian Zhang ◽  
Karyn Foster ◽  
Qiuju Li ◽  
Jeffrey R. Martens
Keyword(s):  
Cell Surface ◽  
Time Course ◽  
Electrical Response ◽  
Proteasome Inhibitors ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Channel Protein ◽  
Kv Channels ◽  
Channel Expression ◽  
Intracellular Compartments

The number of ion channels expressed on the cell surface shapes the complex electrical response of excitable cells. An imbalance in the ratio of inward and outward conducting channels is unfavorable and often detrimental. For example, over- or underexpression of voltage-gated K+ (Kv) channels can be cytotoxic and in some cases lead to disease. In this study, we demonstrated a novel role for S-acylation in Kv1.5 cell surface expression. In transfected fibroblasts, biochemical evidence showed that Kv1.5 is posttranslationally modified on both the NH2 and COOH termini via hydroxylamine-sensitive thioester bonds. Pharmacological inhibition of S-acylation, but not myristoylation, significantly decreased Kv1.5 expression and resulted in accumulation of channel protein in intracellular compartments and targeting for degradation. Channel protein degradation was rescued by treatment with proteasome inhibitors. Time course experiments revealed that S-acylation occurred in the biosynthetic pathway of nascent channel protein and showed that newly synthesized Kv1.5 protein, but not protein expressed on the cell surface, is sensitive to inhibitors of thioacylation. Sensitivity to inhibitors of S-acylation was governed by COOH-terminal, but not NH2-terminal, cysteines. Surprisingly, although intracellular cysteines were required for S-acylation, mutation of these residues resulted in an increase in Kv1.5 cell surface channel expression, suggesting that screening of free cysteines by fatty acylation is an important regulatory step in the quality control pathway. Together, these results show that S-acylation can regulate steady-state expression of Kv1.5.

scholarly journals Cell biology and function of neuronal ceroid lipofuscinosis-related proteins

2013 ◽  
Vol 1832 (11) ◽  
pp. 1866-1881 ◽  
Author(s):  
Katrin Kollmann ◽  
Kristiina Uusi-Rauva ◽  
Enzo Scifo ◽  
Jaana Tyynelä ◽  
Anu Jalanko ◽  
...  
Keyword(s):  
Cell Biology ◽  
Neuronal Ceroid Lipofuscinosis ◽  
Ceroid Lipofuscinosis ◽  
And Function ◽  
Related Proteins

Ocular morphology and function in juvenile neuronal ceroid lipofuscinosis (CLN3) in the first decade of life

2016 ◽  
Vol 38 (3) ◽  
pp. 252-259 ◽  
Author(s):  
Markus N. Preising ◽  
Michaela Abura ◽  
Melanie Jäger ◽  
Klaus-Heiko Wassill ◽  
Birgit Lorenz
Keyword(s):  
Neuronal Ceroid Lipofuscinosis ◽  
Juvenile Neuronal Ceroid Lipofuscinosis ◽  
Ceroid Lipofuscinosis ◽  
And Function

scholarly journals CD63 interacts with the carboxy terminus of the colonic H+-K+-ATPase to increase plasma membrane localization and86Rb+uptake

2005 ◽  
Vol 288 (6) ◽  
pp. C1279-C1286 ◽  
Author(s):  
Juan Codina ◽  
Jian Li ◽  
Thomas D. DuBose
Keyword(s):  
Plasma Membrane ◽  
Protein Interactions ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Carboxy Terminus ◽  
Protein Protein Interactions ◽  
Α Subunit ◽  
Hek 293 ◽  
And Function

The carboxy terminus (CT) of the colonic H+-K+-ATPase is required for stable assembly with the β-subunit, translocation to the plasma membrane, and efficient function of the transporter. To identify protein-protein interactions involved in the localization and function of HKα2, we selected 84 amino acids in the CT of the α-subunit of mouse colonic H+-K+-ATPase (CT-HKα2) as the bait in a yeast two-hybrid screen of a mouse kidney cDNA library. The longest identified clone was CD63. To characterize the interaction of CT-HKα2with CD63, recombinant CT-HKα2and CD63 were synthesized in vitro and incubated, and complexes were immunoprecipitated. CT-HKα2protein (but not CT-HKα1) coprecipitated with CD63, confirming stable assembly of HKα2with CD63. In HEK-293 transfected with HKα2plus β1-Na+-K+-ATPase, suppression of CD63 by RNA interference increased cell surface expression of HKα2/NKβ1and86Rb+uptake. These studies demonstrate that CD63 participates in the regulation of the abundance of the HKα2-NKβ1complex in the cell membrane.

Shared requirement for dynein function and intact microtubule cytoskeleton for normal surface expression of cardiac potassium channels

2009 ◽  
Vol 296 (1) ◽  
pp. H71-H83 ◽  
Author(s):  
Matthew E. Loewen ◽  
Zhuren Wang ◽  
Jodene Eldstrom ◽  
Alireza Dehghani Zadeh ◽  
Anu Khurana ◽  
...  
Keyword(s):  
Potassium Channels ◽  
Potassium Channel ◽  
Ventricular Myocytes ◽  
Potassium Currents ◽  
Surface Expression ◽  
Normal Surface ◽  
Peak Current Density ◽  
Hek 293 ◽  
Channel Expression ◽  
Dependent Transport

Potassium channels at the cardiomyocyte surface must eventually be internalized and degraded, and changes in cardiac potassium channel expression are known to occur during myocardial disease. It is not known which trafficking pathways are involved in the control of cardiac potassium channel surface expression, and it is not clear whether all cardiac potassium channels follow a common pathway or many pathways. In the present study we have surveyed the role of retrograde microtubule-dependent transport in modulating the surface expression of several cardiac potassium channels in ventricular myocytes and heterologous cells. The disruption of microtubule transport in rat ventricular myocytes with nocodazole resulted in significant changes in potassium currents. A-type currents were enhanced 1.6-fold at +90 mV, rising from control densities of 20.9 ± 2.8 to 34.0 ± 5.4 pA/pF in the nocodazole-treated cells, whereas inward rectifier currents were reduced by one-third, perhaps due to a higher nocodazole sensitivity of Kir channel forward trafficking. These changes in potassium currents were associated with a significant decrease in action potential duration. When expressed in heterologous human embryonic kidney (HEK-293) cells, surface expression of Kv4.2, known to substantially underlie A-type currents in rat myocytes, was increased by nocodazole, by the dynein inhibitor erythro-9-(2-hydroxy-3-nonyl) adenine hydrochloride, and by p50 overexpression, which specifically interferes with dynein motor function. Peak current density was 360 ± 61.0 pA/pF in control cells and 658 ± 94.5 pA/pF in cells overexpressing p50. The expression levels of Kv2.1, Kv3.1, human ether-a-go-go-related gene, and Kir2.1 were similarly increased by p50 overexpression in this system. Thus the regulation of potassium channel expression involves a common dynein-dependent process operating similarly on the various channels.

scholarly journals Intravitreal enzyme replacement preserves retinal structure and function in canine CLN2 neuronal ceroid lipofuscinosis

2020 ◽  
Vol 197 ◽  
pp. 108130 ◽  
Author(s):  
Rebecca E.H. Whiting ◽  
Jacqueline W. Pearce ◽  
Daniella P. Vansteenkiste ◽  
Katherine Bibi ◽  
Stefanie Lim ◽  
...  
Keyword(s):  
Neuronal Ceroid Lipofuscinosis ◽  
Structure And Function ◽  
Enzyme Replacement ◽  
Ceroid Lipofuscinosis ◽  
Retinal Structure ◽  
And Function

scholarly journals Proteomic and functional mapping of cardiac NaV1.5 channel phosphorylation reveals multisite regulation of surface expression and gating

2020 ◽  
Author(s):  
Maxime Lorenzini ◽  
Sophie Burel ◽  
Adrien Lesage ◽  
Emily Wagner ◽  
Camille Charrière ◽  
...  
Keyword(s):  
Mass Spectrum ◽  
Mass Range ◽  
Surface Expression ◽  
Phosphorylation Sites ◽  
Hek 293 ◽  
Tandem Mass Tag ◽  
293 Cells ◽  
Peptide Precursors ◽  
Channel Expression ◽  
Underlying Mechanisms

AbstractPhosphorylation of NaV1.5 channels regulates cardiac excitability, yet the phosphorylation sites regulating channel function and the underlying mechanisms remain largely unknown. Using a systematic quantitative phosphoproteomic approach, we analyzed NaV1.5 channel complexes purified from non-failing and failing mouse left ventricles, and we identified 42 phosphorylation sites on NaV1.5. Most sites are clustered, and three of these clusters are highly phosphorylated. Analyses of phosphosilent and phosphomimetic NaV1.5 mutants revealed the roles of three phosphosites in regulating NaV1.5 channel expression and gating. The phosphorylated serines-664 and -667 regulate the voltage-dependence of channel activation in a cumulative manner, whereas phosphorylation of the nearby serine-671, which is increased in failing hearts, decreases cell surface NaV1.5 expression and peak Na+ current. No additional roles could be assigned to the other clusters of phosphosites. Taken together, the results demonstrate that ventricular NaV1.5 is highly phosphorylated, and that the phosphorylation-dependent regulation of NaV1.5-encoded channels is highly complex, site-specific and dynamic.AbbreviationsA, alanine; E, glutamate; HEK-293, Human Embryonic Kidney 293 cells; INa, peak Na+ current; INaL, late Na+ current; IP, immunoprecipitation; mαNaVPAN, anti-NaV channel subunit mouse monoclonal antibody; MS, Mass Spectrometry; MS1, mass spectrum of peptide precursors; MS2 or MS/MS, fragmentation mass spectrum of peptides selected in narrow mass range (2 Da) from MS1 scan; NaV, voltage-gated Na+ channel; pS, phosphoserine; pT, phosphothreonine; S, serine; T, threonine; TAC, Transverse Aortic Constriction; TMT, Tandem Mass Tag.

Sign in / Sign up

Export Citation Format

Share Document