| Title |
Regulation of human extraneuronal monoamine transporter (hEMT) expressed in HEK293 cells by intracellular second messenger systems
|
|---|---|
| Published in |
Naunyn-Schmiedeberg's Archives of Pharmacology, February 2014
|
| DOI | 10.1007/s002100100476 |
| Pubmed ID | |
| Authors |
F. Martel, E. Keating, C. Calhau, D. Gründemann, E. Schömig, I. Azevedo |
| Abstract |
Several transmembrane transporters of organic compounds are regulated by phosphorylation/dephosphorylation mechanisms. The aim of this study was to investigate the possible regulation of the human extraneuronal monoamine transporter, hEMT, by these mechanisms. The experiments were performed using HEK293 cells stably transfected with pcDNA3hEMT (293hEMT). The characteristics of hEMT-mediated uptake of [3H]1-methyl-4-phenylpyridinium ([3H]MPP+) were studied by incubating the cells at 37 degrees C for 1 min with 200 nM [3H]MPP+. Uptake of [3H]MPP+ by 293hEMT cells was not affected or only slightly reduced by modulators of protein kinase A, protein kinase C, or protein kinase G. It was not affected by an inhibitor of protein tyrosine kinase and was reduced by mitogen-activated protein kinase inhibitors. Uptake of [3H]MPP+ by 293hEMT cells was independent of extracellular Ca2+ and strongly reduced by Ca2+/calmodulin pathway inhibitors. Uptake of [3H]MPP+ by 293hEMT cells was strongly reduced in the presence of non-selective phosphodiesterase inhibitors (IBMX, caffeine, theophylline). The effect of IBMX was independent of extracellular Ca2+ its IC50 was found to be 82.0 microM (66.2-101.6 microM; n=4), and its inhibitory effect resulted from a significant decrease in the maximal velocity of [3H]MPP+ uptake, with no change in the Michaelis-Menten constant. [3H]MPP+ uptake was reduced by 8-methoxy-methyl-IBMX, a selective inhibitor of the Ca2+/calmodulin-dependent phosphodiesterase (PDE1), but not by zaprinast, a selective inhibitor of PDE5. Uptake of [3H]MPP+ by 293hEMT cells was strongly reduced by protein tyrosine phosphatase inhibitors, by an alkaline phosphatase inhibitor and, by contrast. showed an increase in the presence of exogenous alkaline phosphatase. In conclusion, these results suggest that hEMT is regulated by phosphorylation/dephosphorylation mechanisms, being active in the dephosphorylated state. |
Mendeley readers
The data shown below were compiled from readership statistics for 19 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 19 | 100% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Professor > Associate Professor | 3 | 16% |
| Researcher | 3 | 16% |
| Student > Ph. D. Student | 3 | 16% |
| Student > Doctoral Student | 2 | 11% |
| Professor | 2 | 11% |
| Other | 2 | 11% |
| Unknown | 4 | 21% |
| Readers by discipline | Count | As % |
|---|---|---|
| Agricultural and Biological Sciences | 6 | 32% |
| Biochemistry, Genetics and Molecular Biology | 3 | 16% |
| Pharmacology, Toxicology and Pharmaceutical Science | 2 | 11% |
| Business, Management and Accounting | 1 | 5% |
| Psychology | 1 | 5% |
| Other | 3 | 16% |
| Unknown | 3 | 16% |
Attention Score in Context
This research output has an Altmetric Attention Score of 3. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 20 December 2007.
All research outputs
#8,515,480
of 25,388,229 outputs
Outputs from Naunyn-Schmiedeberg's Archives of Pharmacology
#437
of 1,922 outputs
Outputs of similar age
#99,109
of 324,452 outputs
Outputs of similar age from Naunyn-Schmiedeberg's Archives of Pharmacology
#3
of 14 outputs
Altmetric has tracked 25,388,229 research outputs across all sources so far. This one is in the 43rd percentile – i.e., 43% of other outputs scored the same or lower than it.
So far Altmetric has tracked 1,922 research outputs from this source. They receive a mean Attention Score of 4.2. This one is in the 30th percentile – i.e., 30% of its peers scored the same or lower than it.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 324,452 tracked outputs that were published within six weeks on either side of this one in any source. This one is in the 48th percentile – i.e., 48% of its contemporaries scored the same or lower than it.
We're also able to compare this research output to 14 others from the same source and published within six weeks on either side of this one. This one is in the 14th percentile – i.e., 14% of its contemporaries scored the same or lower than it.