CRAC channel opening is determined by a series of Orai1 gating checkpoints in the transmembrane and cytosolic regions

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388971%3A_____%2F21%3A00549327" target="_blank" >RIV/61388971:_____/21:00549327 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11320/21:10438873

Výsledek na webu

<a href="https://www.jbc.org/article/S0021-9258(20)00339-7/pdf" target="_blank" >https://www.jbc.org/article/S0021-9258(20)00339-7/pdf</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1074/jbc.RA120.015548" target="_blank" >10.1074/jbc.RA120.015548</a>

Jazyk výsledku

angličtina

Název v původním jazyce

CRAC channel opening is determined by a series of Orai1 gating checkpoints in the transmembrane and cytosolic regions

Popis výsledku v původním jazyce

The initial activation step in the gating of ubiquitously expressed Orai1 calcium (Ca2+) ion channels represents the activation of the Ca2+-sensor protein STIM1 upon Ca2+ store depletion of the endoplasmic reticulum. Previous studies using constitutively active Orai1 mutants gave rise to, but did not directly test, the hypothesis that STIM1-mediated Orai1 pore opening is accompanied by a global conformational change of all Orai transmembrane domain (TM) helices within the channel complex. We prove that a local conformational change spreads omnidirectionally within the Orai1 complex. Our results demonstrate that these locally induced global, opening-permissive TM motions are indispensable for pore opening and require clearance of a series of Orai1 gating checkpoints. We discovered these gating checkpoints in the middle and cytosolic extended TM domain regions. Our findings are based on a library of double point mutants that contain each one loss-of-function with one gain-of-function point mutation in a series of possible combinations. We demonstrated that an array of loss-of-function mutations are dominant over most gain-of-function mutations within the same as well as of an adjacent Orai subunit. We further identified inter- and intramolecular salt-bridge interactions of Orai subunits as a core element of an opening-permissive Orai channel architecture. Collectively, clearance and synergistic action of all these gating checkpoints are required to allow STIM1 coupling and Orai1 pore opening. Our results unravel novel insights in the preconditions of the unique fingerprint of CRAC channel activation, provide a valuable source for future structural resolutions, and help to understand the molecular basis of disease-causing mutations.

Název v anglickém jazyce

CRAC channel opening is determined by a series of Orai1 gating checkpoints in the transmembrane and cytosolic regions

Popis výsledku anglicky

The initial activation step in the gating of ubiquitously expressed Orai1 calcium (Ca2+) ion channels represents the activation of the Ca2+-sensor protein STIM1 upon Ca2+ store depletion of the endoplasmic reticulum. Previous studies using constitutively active Orai1 mutants gave rise to, but did not directly test, the hypothesis that STIM1-mediated Orai1 pore opening is accompanied by a global conformational change of all Orai transmembrane domain (TM) helices within the channel complex. We prove that a local conformational change spreads omnidirectionally within the Orai1 complex. Our results demonstrate that these locally induced global, opening-permissive TM motions are indispensable for pore opening and require clearance of a series of Orai1 gating checkpoints. We discovered these gating checkpoints in the middle and cytosolic extended TM domain regions. Our findings are based on a library of double point mutants that contain each one loss-of-function with one gain-of-function point mutation in a series of possible combinations. We demonstrated that an array of loss-of-function mutations are dominant over most gain-of-function mutations within the same as well as of an adjacent Orai subunit. We further identified inter- and intramolecular salt-bridge interactions of Orai subunits as a core element of an opening-permissive Orai channel architecture. Collectively, clearance and synergistic action of all these gating checkpoints are required to allow STIM1 coupling and Orai1 pore opening. Our results unravel novel insights in the preconditions of the unique fingerprint of CRAC channel activation, provide a valuable source for future structural resolutions, and help to understand the molecular basis of disease-causing mutations.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10606 - Microbiology

Projekt

<a href="/cs/project/GJ19-20728Y" target="_blank" >GJ19-20728Y: Modelování aktivace lidských vápníkových kanálů zavislých na koncentraci uvolněneho vapníku.</a><br>

Návaznosti

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

Rok uplatnění

2021

Kód důvěrnosti údajů

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

Název periodika

Journal of Biological Chemistry

ISSN

0021-9258

e-ISSN

1083-351X

Svazek periodika

296

Číslo periodika v rámci svazku

JAN-JUN 2021

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

21

Strana od-do

100224

Kód UT WoS článku

000672866400202

EID výsledku v databázi Scopus

2-s2.0-85101713436