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Epithelial Na(+) channels (ENaC) mediate the transport of sodium (Na) across epithelia in the kidney, gut, and lungs and are required for blood pressure regulation. They are inhibited by ubiquitin protein ligases, such as Nedd4 and Nedd4-2, which bind to proline-rich motifs (PY motifs) present in the C-termini of ENaC subunits. Loss of inhibition leads to hypertension. ENaC channels are maintained in the active state by G-protein-coupled receptor kinase 2 (GRK2), an enzyme implicated in the development of essential hypertension. Here, we report that GRK2 interacts not only with ENaC, but also with both Nedd4 and Nedd4-2. Additionally, GRK2 is capable of phosphorylating both Nedd4 and Nedd4-2 at multiple sites. Of possible significance is the phosphorylation of the threonine at position 466 in Nedd4, which is located in the area of the ww3 domain that binds ENaC. These results support and extend the role of GRK2 in sodium transport regulation.
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http://dx.doi.org/10.1016/j.bbrc.2007.05.134 | DOI Listing |
Eur J Pharmacol
September 2025
Cardiovascular Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, Louisiana, 70112, USA; Department of Pharmacology & Experimental Therapeutics, New Orleans, LA, 70112 USA; Southeast Louisiana Veterans Health Care System, New Orleans, LA 70119, USA. Electronic addr
The renin-angiotensin system (RAS) is central to cardiovascular diseases such as hypertension and cardiomyopathy, yet the functions of many RAS genes remain unclear. This study developed a multi-label deep learning model to systematically annotate RAS gene functions and elucidate their roles in biological pathways. A total of 39,463 RAS-related publications from PubMed and PMC were processed into text format.
View Article and Find Full Text PDFCell Death Discov
August 2025
Centre for Cancer Biology, University of South Australia, Adelaide, SA, Australia.
NEDD4-2 (human NEDD4L), a ubiquitin ligase, plays an essential role in regulating a number of membrane proteins, including ion channels and transporters. In the kidney, NEDD4-2 deletion results in a progressive loss of tubular cells and salt-sensitive chronic kidney disease. While deregulation of sodium homeostasis due to increased levels and function of the epithelial sodium channel (ENaC) and sodium chloride transporter (NCC), both NEDD4-2 substrates, plays a critical role in kidney damage in this model, other ubiquitination targets may also be important.
View Article and Find Full Text PDFCell Commun Signal
July 2025
Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
The degradation of voltage-gated calcium channels (VGCC), which are key determinants of neuronal excitability and muscle contraction, is crucial for regulating calcium homeostasis and can be targeted for analgesic drug discovery. Molecularly, both the ubiquitin-proteasomal system and lysosomal pathways play critical roles in VGCC turnover with the involvement of ubiquitin-conjugating E2 enzyme UBE2L3, multiple ubiquitin-ligating E3 ligases including Rfp2, Mdm2, Nedd4-1 and WWP1, and deubiquitinase USP5. Physiologically, a blocking peptide and small molecules interfering with the Ca3.
View Article and Find Full Text PDFCell Death Dis
July 2025
Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, SA, Australia.
NEDD4-2, a ubiquitin ligase, regulates a number of ion channels and transporters by promoting their ubiquitination, internalisation and degradation, thereby affecting many signalling and physiological outcomes. Loss of this gene in mice results in tubular cell death and a chronic kidney disease (CKD)-like phenotype due to aberrant Na transport, caused by elevated expression of NEDD4-2 substrates including the epithelial sodium channel (ENaC). One of the biggest risk factors for CKD is diabetes, as up to 50% of diabetic patients develop diabetic kidney disease (DKD).
View Article and Find Full Text PDFNat Commun
May 2025
Institute of Physiology of the Czech Academy of Sciences, Laboratory of Structural Biology of Signaling Proteins, Division BIOCEV, Prumyslova 595, 252 50, Vestec, Czech Republic.
Nedd4-2 E3 ligase regulates Na homeostasis by ubiquitinating various channels and membrane transporters, including the epithelial sodium channel ENaC. In turn, Nedd4-2 dysregulation leads to various conditions, including electrolytic imbalance, respiratory distress, hypertension, and kidney diseases. However, Nedd4-2 regulation remains mostly unclear.
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