scholarly journals Increased GABA Transport Activity in Rat Calvarial Osteoblasts Cultured under Hyperglycemic Conditions

2006 ◽  
Vol 29 (2) ◽  
pp. 297-301 ◽  
Author(s):  
Sayumi Fujimori ◽  
Masato Osawa ◽  
Mika Iemata ◽  
Eiichi Hinoi ◽  
Yukio Yoneda
Keyword(s):  
Transport Activity ◽  
Gaba Transport

scholarly journals Functional sensitivity of polar surfaces on transmembrane helix 8 and cytoplasmic loop 8-9 of the Escherichia coli GABA (4-aminobutyrate) transporter encoded by gabP: mutagenic analysis of a consensus amphipathic region found in transporters from bacteria to mammals

1998 ◽  
Vol 330 (2) ◽  
pp. 771-776 ◽  
Author(s):  
A. Liaoyuan HU ◽  
C. Steven KING
Keyword(s):  
Escherichia Coli ◽  
Nervous System ◽  
Deleterious Effect ◽  
Transmembrane Helix ◽  
Transport Activity ◽  
Gaba Transport ◽  
Gaba Transporters ◽  
Gabaergic Synapses ◽  
Gaba Analogues ◽  
The Many

The gab permease (GabP) catalyses transport of GABA (4-aminobutyrate) into Escherichia coli. Although GabP can recognize and transport many GABA analogues that exhibit activity at GABAergic synapses in the nervous system, the protein domains responsible for these transport and ligand recognition properties have not been studied. Here we report that an amphipathic domain extending through putative transmembrane helix 8 and into the adjoining cytoplasmic region (loop 8-9) contains a critical 20 residue zone within which mutagenesis of polar amino acids has a deleterious effect on [3H]GABA transport activity. This functionally important amphipathic domain is found to be highly conserved in the many APC family transporters that are homologous to GabP. And even though members of the GAT family of GABA transporters from the animal nervous system are not homologous to GabP, an analogous amphipathic structure is found in their loop 8-9 region. These results and observations suggest: (1) that the consensus amphipathic region (CAR) in the putative helix 8 and loop 8-9 region of GabP has functional significance, and (2) that nature has repeatedly used this CAR in transporters from bacteria to mammals.

Glucose as regulator of glucose transport activity and glucose-transporter mRNA in hamster beta-cell line

Diabetes ◽  
1992 ◽  
Vol 41 (5) ◽  
pp. 592-597 ◽  
Author(s):  
N. Inagaki ◽  
K. Yasuda ◽  
G. Inoue ◽  
Y. Okamoto ◽  
H. Yano ◽  
...  
Keyword(s):  
Beta Cell ◽  
Cell Line ◽  
Glucose Transport ◽  
Glucose Transporter ◽  
Transport Activity ◽  
Beta Cell Line ◽  
Glucose Transporter Mrna

Modulation of a Cellular Transport Activity by Capsicum Extracts

2018 ◽  
Vol 14 (2) ◽  
pp. 149-152
Author(s):  
Jie Chen ◽  
Vai H. Fong ◽  
Amandio Vieira
Keyword(s):  
Cellular Transport ◽  
Transport Activity

scholarly journals B0AT1 amino acid transporter complexed with SARS-CoV-2 receptor ACE2 forms a heterodimer functional unit: in situ conformation using radiation inactivation analysis

Function ◽  
2021 ◽  
Author(s):  
Bruce R Stevens ◽  
J Clive Ellory ◽  
Robert L Preston
Keyword(s):  
Amino Acid ◽  
Membrane Trafficking ◽  
Functional Unit ◽  
Membrane Vesicles ◽  
High Energy ◽  
Amino Acid Transporter ◽  
Neutral Amino Acid ◽  
Transport Activity ◽  
Acid Transporter

Abstract The SARS-CoV-2 receptor, Angiotensin Converting Enzyme-2 (ACE2), is expressed at levels of greatest magnitude in the small intestine as compared to all other human tissues. Enterocyte ACE2 is co-expressed as the apical membrane trafficking partner obligatory for expression and activity of the B0AT1 sodium-dependent neutral amino acid transporter. These components are assembled as an [ACE2: B0AT1]2 dimer-of-heterodimers quaternary complex that putatively steers SARS-CoV-2 tropism in the gastrointestinal (GI) tract. GI clinical symptomology is reported in about half of COVID-19 patients, and can be accompanied by gut shedding of virion particles. We hypothesized that within this 4-mer structural complex, each [ACE2: B0AT1] heterodimer pair constitutes a physiological “functional unit.” This was confirmed experimentally by employing purified lyophilized enterocyte brush border membrane vesicles that were exposed to increasing doses of high-energy electron radiation from a 16 MeV linear accelerator. Based on established target theory, the results indicated the presence of Na+-dependent neutral amino acid influx transport activity functional unit with target size mw = 183.7 ± 16.8 kDa in situ in intact apical membranes. Each thermodynamically stabilized [ACE2: B0AT1] heterodimer functional unit manifests the transport activity within the whole ∼345 kDa [ACE2: B0AT1]2 dimer-of-heterodimers quaternary structural complex. The results are consistent with our prior molecular docking modeling and gut-lung axis approaches to understanding COVID-19. These findings advance the understanding of the physiology of B0AT1 interaction with ACE2 in the gut, and thereby potentially contribute to translational developments designed to treat or mitigate COVID-19 variant outbreaks and/or GI symptom persistence in long-haul Post-Acute Sequelae of SARS-CoV-2 (PASC).

scholarly journals L1210/B23.1 cells express equilibrative, inhibitor-sensitive nucleoside transport activity and lack two parental nucleoside transport activities.

1992 ◽  
Vol 267 (24) ◽  
pp. 16951-16956
Author(s):  
D Vijayalakshmi ◽  
L Dagnino ◽  
J.A. Belt ◽  
W.P. Gati ◽  
C.E. Cass ◽  
...  
Keyword(s):  
Nucleoside Transport ◽  
Transport Activity
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