Dynamitin affects cell-surface expression of voltage-gated sodium channel Nav1.5

2014 ◽  
Vol 463 (3) ◽  
pp. 339-349 ◽  
Author(s):  
Benoît Chatin ◽  
Pauline Colombier ◽  
Anne Laure Gamblin ◽  
Marie Allouis ◽  
Françoise Le Bouffant

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.

2013 ◽  
Vol 305 (1) ◽  
pp. F80-F89 ◽  
Author(s):  
Yong Feng Liu ◽  
Marianne Swart ◽  
Ying Ke ◽  
Kevin Ly ◽  
Fiona J. McDonald

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.


2015 ◽  
Vol 290 (19) ◽  
pp. 12048-12057 ◽  
Author(s):  
Chao Liu ◽  
Francis Chee Kuan Tan ◽  
Zhi-Cheng Xiao ◽  
Gavin S. Dawe

FEBS Letters ◽  
2013 ◽  
Vol 587 (19) ◽  
pp. 3159-3165 ◽  
Author(s):  
Pedro Beltran-Alvarez ◽  
Alexsandra Espejo ◽  
Ralf Schmauder ◽  
Carlos Beltran ◽  
Ralf Mrowka ◽  
...  

2010 ◽  
Vol 298 (6) ◽  
pp. F1445-F1456 ◽  
Author(s):  
Ying Ke ◽  
A. Grant Butt ◽  
Marianne Swart ◽  
Yong Feng Liu ◽  
Fiona J. McDonald

The epithelial sodium channel (ENaC) is important for the long-term control of Na+ homeostasis and blood pressure. Our previous studies demonstrated that Copper Metabolism Murr1 Domain-containing protein 1 (COMMD1; previously known as Murr1), a protein involved in copper metabolism, inhibited amiloride-sensitive current in Xenopus laevis oocytes expressing ENaC ( J Biol Chem 279: 5429, 2004). In this study, we report that COMMD1 inhibits amiloride-sensitive current in mammalian epithelial cells expressing ENaC, that the COMM domain of COMMD1 is sufficient for this effect, and that knockdown of COMMD1 increases amiloride-sensitive current. COMMD1 is coexpressed with ENaC in rat kidney medulla cells. COMMD1 increased ubiquitin modification of ENaC and decreased its cell surface expression. COMMD1 abolished insulin-stimulated amiloride-sensitive current and attenuated the stimulation of current by activated serum and glucocorticoid-regulated kinase (SGK1). COMMD1 was found to interact with both SGK1 and Akt1/protein kinase B, and knockdown of COMMD1 enhanced the stimulatory effect of both SGK1 and Akt1 on amiloride-sensitive current. COMMD1's effects were reduced in the presence of ENaC proteins containing PY motif mutations, abolished in the presence of a dominant negative form of Nedd4–2, and knockdown of COMMD1 reduced the inhibitory effect of Nedd4–2 on ENaC, but did not enhance current when Nedd4–2 was knocked down. These data suggest that COMMD1 modulates Na+ transport in epithelial cells through regulation of ENaC cell surface expression and this effect is likely mediated via Nedd4–2.


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