PT  - JOURNAL ARTICLE
AU  - Le Gui
AU  - Jinhui Zhu
AU  - Xiangru Lu
AU  - Stephen M. Sims
AU  - Wei-Yang Lu
AU  - Peter B. Stathopulos
AU  - Qingping Feng
TI  - S-Nitrosylation of STIM1 by neuronal nitric oxide synthase inhibits store-operated Ca<sup>2+</sup> entry
AID  - 10.1101/304022
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 304022
4099  - http://biorxiv.org/content/early/2018/04/18/304022.short
4100  - http://biorxiv.org/content/early/2018/04/18/304022.full
AB  - Store-operated Ca2+ entry (SOCE) mediated by stromal interacting molecule-1 (STIM1) and Orai1 represents a major route of Ca2+ entry in mammalian cells and is initiated by STIM1 oligomerization in the endoplasmic or sarcoplasmic reticulum (ER/SR). However, the effects of nitric oxide (NO) on STIM1 function are unknown. Neuronal NO synthase (nNOS) is located in the SR of cardiomyocytes. Here, we show that STIM1 is susceptible to S-nitrosylation. nNOS deficiency or inhibition enhanced Ca2+ release-activated Ca2+ channel current (ICRAC) and SOCE in cardiomyocytes. Consistently, NO donor S-nitrosoglutathione (GSNO) inhibited STIM1 puncta formation and ICRAC in HEK293 cells, but this effect was absent in cells expressing the Cys49Ser/Cys56Ser STIM1 double mutant. Furthermore, NO donors caused Cys49 and Cys56-specific structural changes associated with reduced protein backbone mobility, increased thermal stability and suppressed Ca2+-depletion-dependent oligomerization of the luminal Ca2+-sensing region of STIM1. Collectively, our data show that S-nitrosylation of STIM1 suppresses oligomerization via enhanced luminal domain stability and rigidity, and inhibits SOCE in cardiomyocytes.