The S. cerevisiae cation translocation protein Trk1 is functional without its long hydrophilic 'loop' but LHL regulates cation translocation activity and selectivity

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388971%3A_____%2F19%3A00509066" target="_blank" >RIV/61388971:_____/19:00509066 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/60076658:12310/19:43899560

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0005273619301427?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0005273619301427?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.bbamem.2019.06.010" target="_blank" >10.1016/j.bbamem.2019.06.010</a>

Jazyk výsledku

angličtina

Název v původním jazyce

The S. cerevisiae cation translocation protein Trk1 is functional without its long hydrophilic 'loop' but LHL regulates cation translocation activity and selectivity

Popis výsledku v původním jazyce

In Saccharomyces cerevisiae, K+-uptake under K+-limiting conditions is largely mediated by the cation translocation systems Trk1 and Trk2 belonging to the family of SKT proteins. They are related to two-transmembrane-domain (inward rectifying K-) channels but unlike the symmetrical tetrameric structure of K-channels, a single Trk contains four pore-forming domains (A-D) encoded on one polypeptide chain. Between domains A and B Trks contain large cytosolic regions dubbed 'long hydrophilic loop' (LHL). LHLs are not homologous/similar to any other identified protein (domain) and also show little similarity between Trk1 and Trk2. Here we demonstrate that Trk1 is functional without LHL. However, in growth experiments NaCl sensitivity of Trk1 [Delta LHL] expressing cells is increased under K+-limiting conditions compared to full-length Trk1. Non-invasive ion flux measurements showed that K+-influx through Trk1 and Trk1 [Delta LHL] is decreased in the presence of surplus Na+ due to permeability of the proteins for both cations and competition between them. Trk1 [Delta LHL] is less affected than full-length Trk1 because it is more selective for K+ over Na+. Furthermore, K+ re-uptake after starvation is delayed and decreased in Trk1 [Delta LHL]. Thus, a role of LHL is regulating cation fluxes through Trk1 by (i) allowing also Na+ to pass if monovalent cations (mainly K+) are limiting and (ii) by accelerating/enhancing a switch from low to high affinity ion translocation. We propose that LHL could modulate Trk1 transport properties via direct influence on a transmembrane helix (M2(A)) which can switch between bent and straight conformation, thereby directly modifying the radius of the pore and selectivity filter.

Název v anglickém jazyce

The S. cerevisiae cation translocation protein Trk1 is functional without its long hydrophilic 'loop' but LHL regulates cation translocation activity and selectivity

Popis výsledku anglicky

In Saccharomyces cerevisiae, K+-uptake under K+-limiting conditions is largely mediated by the cation translocation systems Trk1 and Trk2 belonging to the family of SKT proteins. They are related to two-transmembrane-domain (inward rectifying K-) channels but unlike the symmetrical tetrameric structure of K-channels, a single Trk contains four pore-forming domains (A-D) encoded on one polypeptide chain. Between domains A and B Trks contain large cytosolic regions dubbed 'long hydrophilic loop' (LHL). LHLs are not homologous/similar to any other identified protein (domain) and also show little similarity between Trk1 and Trk2. Here we demonstrate that Trk1 is functional without LHL. However, in growth experiments NaCl sensitivity of Trk1 [Delta LHL] expressing cells is increased under K+-limiting conditions compared to full-length Trk1. Non-invasive ion flux measurements showed that K+-influx through Trk1 and Trk1 [Delta LHL] is decreased in the presence of surplus Na+ due to permeability of the proteins for both cations and competition between them. Trk1 [Delta LHL] is less affected than full-length Trk1 because it is more selective for K+ over Na+. Furthermore, K+ re-uptake after starvation is delayed and decreased in Trk1 [Delta LHL]. Thus, a role of LHL is regulating cation fluxes through Trk1 by (i) allowing also Na+ to pass if monovalent cations (mainly K+) are limiting and (ii) by accelerating/enhancing a switch from low to high affinity ion translocation. We propose that LHL could modulate Trk1 transport properties via direct influence on a transmembrane helix (M2(A)) which can switch between bent and straight conformation, thereby directly modifying the radius of the pore and selectivity filter.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10607 - Virology

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Biochimica Et Biophysica Acta-Biomembranes

ISSN

0005-2736

e-ISSN

—

Svazek periodika

1861

Číslo periodika v rámci svazku

8

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

13

Strana od-do

1476-1488

Kód UT WoS článku

000477686000007

EID výsledku v databázi Scopus

2-s2.0-85067845090