The high-affinity choline transporter CHT1 is regulated by the ubiquitin ligase Nedd4-2

Yamada, Haruhiko; Imajoh‐Ohmi, Shinobu; Haga, Tatsuya

doi:10.2220/biomedres.33.1

Cited by 16 publications

(7 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Consistent with our results, abolishment of ubiquitination for the glutamate transporter GLT1 required a total of 11 mutations, corresponding to all N - and C -terminus lysines. Similar findings were obtained for the choline transporter CHT1, which required 10 substitutions of the 12 intracellular lysine residues to reduce the levels of ubiquitination [ 13 , 43 ]. The classical example of redundancy is provided by the epidermal growth factor receptor (EGFR), where substitution of a minimum of six lysines in the kinase domain resulted in a dramatic decrease in the overall ubiquitination, but it was still not completely abolished [ 44 ].…”

Section: Discussionsupporting

confidence: 70%

PKC-Dependent GlyT1 Ubiquitination Occurs Independent of Phosphorylation: Inespecificity in Lysine Selection for Ubiquitination

et al. 2015

View full text Add to dashboard Cite

Neurotransmitter transporter ubiquitination is emerging as the main mechanism for endocytosis and sorting of cargo into lysosomes. In this study, we demonstrate PKC-dependent ubiquitination of three different isoforms of the glycine transporter 1 (GlyT1). Incubation of cells expressing transporter with the PKC activator phorbol ester induced a dramatic, time-dependent increase in GlyT1 ubiquitination, followed by accumulation of GlyT1 in EEA1 positive early endosomes. This occurred via a mechanism that was abolished by inhibition of PKC. GlyT1 endocytosis was confirmed in both retinal sections and primary cultures of mouse amacrine neurons. Replacement of only all lysines in the N-and C-termini to arginines prevented ubiquitination and endocytosis, displaying redundancy in the mechanism of ubiquitination. Interestingly, a 40–50% reduction in glycine uptake was detected in phorbol-ester stimulated cells expressing the WT-GlyT1, whereas no significant change was for the mutant protein, demonstrating that endocytosis participates in the reduction of uptake. Consistent with previous findings for the dopamine transporter DAT, ubiquitination of GlyT1 tails functions as sorting signal to deliver transporter into the lysosome and removal of ubiquitination sites dramatically attenuated the rate of GlyT1 degradation. Finally, we showed for the first time that PKC-dependent GlyT1 phosphorylation was not affected by removal of ubiquitination sites, suggesting separate PKC-dependent signaling events for these posttranslational modifications.

show abstract

Section: Discussionsupporting

confidence: 70%

PKC-Dependent GlyT1 Ubiquitination Occurs Independent of Phosphorylation: Inespecificity in Lysine Selection for Ubiquitination

et al. 2015

View full text Add to dashboard Cite

show abstract

“…For example, brain deletion of Nedd4-2 leads to increased ENaC expression and hypertension induced by a high-salt diet that can be prevented by central infusion of the ENaC blocker benzamil7. However, Nedd4-2 can also regulate glutamate, dopamine and the CHT-1 choline transporters, and interacts with a number of neuronal NaV channels in cortical and dorsal root ganglia (DRG) neurons89101112. Recently, the identification of a Nedd4L missense mutation in a patient with epileptic encephalopathy and the isolation of missense mutations in highly conserved residues of Nedd4-2 in families with photosensitive generalized epilepsy has suggested that this E3 ligase, in addition to hypertension, is an epilepsy associated gene and can contribute to CNS pathologies13.…”

mentioning

confidence: 99%

Nedd4-2 haploinsufficiency causes hyperactivity and increased sensitivity to inflammatory stimuli

Yanpallewar

Wang

Koh

et al. 2016

Sci Rep

View full text Add to dashboard Cite

Nedd4-2 (NEDD4L in humans) is a ubiquitin protein ligase best known for its role in regulating ion channel internalization and turnover. Nedd4-2 deletion in mice causes perinatal lethality associated with increased epithelial sodium channel (ENaC) expression in lung and kidney. Abundant data suggest that Nedd4-2 plays a role in neuronal functions and may be linked to epilepsy and dyslexia in humans. We used a mouse model of Nedd4-2 haploinsufficiency to investigate whether an alteration in Nedd4-2 levels of expression affects general nervous system functions. We found that Nedd4-2 heterozygous mice are hyperactive, have increased basal synaptic transmission and have enhanced sensitivity to inflammatory pain. Thus, Nedd4-2 heterozygous mice provide a new genetic model to study inflammatory pain. These data also suggest that in human, SNPs affecting NEDD4L levels may be involved in the development of neuropsychological deficits and peripheral neuropathies and may help unveil the genetic basis of comorbidities.

show abstract

“…To date, the role of ubiquitin and ubiquitination in the regulation of cholinergic function and CHT is largely unknown. A few recent studies suggest that CHT may be ubiquitinated[31] and ubiquitination may be involved in oxidative stress induced protein degradation of CHT[7]. Using TUBE pull-down assay, our study provides novel evidence that CHT undergoes poly-ubiquitination.…”

Section: Discussionmentioning

confidence: 73%

Ubiquitin C-terminal hydrolase L1 interacts with choline transporter in cholinergic cells

Hartnett

Zhang

Abitz

et al. 2014

Neuroscience Letters

View full text Add to dashboard Cite

Ubiquitin carboxyl-terminal hydrolase L1 (UCHL1) is a deubiquitinating enzyme, which is highly expressed in neuronal cells. Previous studies have indicated that UCHL1 is involved in cognitive function, neurodegenerative diseases, and neuromuscular junction development. Acetylcholine (Ach) is a critical neurotransmitter in these functions. Yet, the effect of UCHL1 on the cholinergic system has not been reported. In this study, using a cholinergic neuronal cell line, SN56, as an in vitro model, we detected the physical interaction of UCHL1 and high affinity choline transporter (CHT), which is a key protein regulating Ach re-synthesis. Reduction of UCHL1 by siRNA gene knockdown significantly increased poly-ubiquitinated CHT and decreased native CHT protein level, but did not affect CHT mRNA expression. Biotinylation assay showed that UCHL1 is localized only in the cytosol of the cells and that the gene knockdown of UCHL1 significantly reduced cytosolic CHT but had no significant effect on membrane CHT level. These data provide novel and potentially important evidence that UCHL1 may play a role in the regulation of cholinergic function by affecting CHT ubiquitination and degradation.

show abstract

The high-affinity choline transporter CHT1 is regulated by the ubiquitin ligase Nedd4-2

Cited by 16 publications

References 24 publications

PKC-Dependent GlyT1 Ubiquitination Occurs Independent of Phosphorylation: Inespecificity in Lysine Selection for Ubiquitination

PKC-Dependent GlyT1 Ubiquitination Occurs Independent of Phosphorylation: Inespecificity in Lysine Selection for Ubiquitination

Nedd4-2 haploinsufficiency causes hyperactivity and increased sensitivity to inflammatory stimuli

Ubiquitin C-terminal hydrolase L1 interacts with choline transporter in cholinergic cells

Contact Info

Product

Resources

About