PUBLICATION
The endosomal trafficking regulator LITAF controls the cardiac Nav1.5 channel via the ubiquitin ligase NEDD4-2
- Authors
- Turan, N.N., Moshal, K.S., Roder, K., Baggett, B.C., Kabakov, A.Y., Dhakal, S., Teramoto, R., Chiang, D.Y., Zhong, M., Xie, A., Lu, Y., Dudley, S.C., MacRae, C.A., Karma, A., Koren, G.
- ID
- ZDB-PUB-201024-6
- Date
- 2020
- Source
- The Journal of biological chemistry 295(52): 18148-18159 (Journal)
- Registered Authors
- MacRae, Calum A.
- Keywords
- Action potential duration, Computer modelling, E3 ubiquitin ligase, LITAF, NEDD4-2, Nav1.5, cardiomyocyte, sodium channel, ubiquitin, zebrafish
- MeSH Terms
-
- Action Potentials
- Animals
- Endosomes/metabolism*
- Genome-Wide Association Study
- Humans
- Myocytes, Cardiac/cytology
- Myocytes, Cardiac/metabolism*
- NAV1.5 Voltage-Gated Sodium Channel/genetics
- NAV1.5 Voltage-Gated Sodium Channel/metabolism*
- Nedd4 Ubiquitin Protein Ligases/genetics
- Nedd4 Ubiquitin Protein Ligases/metabolism*
- Nuclear Proteins/genetics
- Nuclear Proteins/metabolism*
- Protein Binding
- Protein Transport
- Rabbits
- Transcription Factors/genetics
- Transcription Factors/metabolism*
- Ubiquitin/metabolism*
- Ubiquitination
- Zebrafish
- PubMed
- 33093176 Full text @ J. Biol. Chem.
Citation
Turan, N.N., Moshal, K.S., Roder, K., Baggett, B.C., Kabakov, A.Y., Dhakal, S., Teramoto, R., Chiang, D.Y., Zhong, M., Xie, A., Lu, Y., Dudley, S.C., MacRae, C.A., Karma, A., Koren, G. (2020) The endosomal trafficking regulator LITAF controls the cardiac Nav1.5 channel via the ubiquitin ligase NEDD4-2. The Journal of biological chemistry. 295(52):18148-18159.
Abstract
The QT interval is a recording of cardiac electrical activity. Previous genome-wide association studies (GWAS) identified genetic variants that modify the QT interval upstream of LITAF (lipopolysaccharide-induced tumor necrosis factor-alpha factor), a protein encoding a regulator of endosomal trafficking. However, it was not clear how LITAF might impact cardiac excitation. We investigated the effect of LITAF on the voltage-gated sodium channel Nav1.5, which is critical for cardiac depolarization. We show that overexpressed LITAF resulted in a significant increase in the density of Nav1.5-generated voltage-gated sodium current INa and Nav1.5 surface protein levels in rabbit cardiomyocytes and in HEK cells stably expressing Nav1.5. Proximity ligation assays showed co-localization of endogenous LITAF and Nav1.5 in cardiomyocytes, while co-immunoprecipitations confirmed they are in the same complex when overexpressed in HEK cells. In vitro data suggests LITAF interacts with the ubiquitin ligase NEDD4-2, a regulator of Nav1.5. LITAF overexpression downregulated NEDD4-2 in cardiomyocytes and HEK cells. In HEK cells, LITAF increased ubiquitination and proteasomal degradation of co-expressed NEDD4-2 and significantly blunted the negative effect of NEDD4-2 on INa We conclude that LITAF controls cardiac excitability by promoting degradation of NEDD4-2, which is essential for removal of surface Nav1.5. LITAF-knockout zebrafish showed increased variation in and a non-significant 15% prolongation of action potential duration (APD). Computer simulations using a rabbit-cardiomyocyte model demonstrated that changes in Ca2+ and Na+ homeostasis are responsible for the surprisingly modest APD shortening. These computational data thus corroborate findings from several GWAS that associated LITAF with QT interval variation.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping