scholarly journals The homocysteine-inducible endoplasmic reticulum (ER) stress protein Herp counteracts mutant α-synuclein-induced ER stress via the homeostatic regulation of ER-resident calcium release channel proteins

2011 ◽  
Vol 21 (5) ◽  
pp. 963-977 ◽  
Author(s):  
Cherine Belal ◽  
Neema J. Ameli ◽  
Adam El Kommos ◽  
Spencer Bezalel ◽  
Aziz M. Al'Khafaji ◽  
...  
2019 ◽  
Vol 116 (28) ◽  
pp. 14154-14163 ◽  
Author(s):  
Sun-Ji Park ◽  
Yeawon Kim ◽  
Shyh-Ming Yang ◽  
Mark J. Henderson ◽  
Wei Yang ◽  
...  

Emerging evidence has established primary nephrotic syndrome (NS), including focal segmental glomerulosclerosis (FSGS), as a primary podocytopathy. Despite the underlying importance of podocyte endoplasmic reticulum (ER) stress in the pathogenesis of NS, no treatment currently targets the podocyte ER. In our monogenic podocyte ER stress-induced NS/FSGS mouse model, the podocyte type 2 ryanodine receptor (RyR2)/calcium release channel on the ER was phosphorylated, resulting in ER calcium leak and cytosolic calcium elevation. The altered intracellular calcium homeostasis led to activation of calcium-dependent cytosolic protease calpain 2 and cleavage of its important downstream substrates, including the apoptotic molecule procaspase 12 and podocyte cytoskeletal protein talin 1. Importantly, a chemical compound, K201, can block RyR2-Ser2808 phosphorylation-mediated ER calcium depletion and podocyte injury in ER-stressed podocytes, as well as inhibit albuminuria in our NS model. In addition, we discovered that mesencephalic astrocyte-derived neurotrophic factor (MANF) can revert defective RyR2-induced ER calcium leak, a bioactivity for this ER stress-responsive protein. Thus, podocyte RyR2 remodeling contributes to ER stress-induced podocyte injury. K201 and MANF could be promising therapies for the treatment of podocyte ER stress-induced NS/FSGS.


2004 ◽  
Vol 380 (1) ◽  
pp. e1-e3 ◽  
Author(s):  
Tommie V. McCARTHY ◽  
John J. MACKRILL

Ryanodine receptors (RyRs) are a family of intracellular channels that mediate Ca2+ release from the endoplasmic and sarcoplasmic reticulum. More than 50 distinct point mutations in one member of this family, RyR1, cause malignant hyperthermia, a potentially lethal pharmacogenetic disorder of skeletal muscle. These mutations are not randomly distributed throughout the primary structure of RyR1, but are grouped in three discrete clusters. In this issue of the Biochemical Journal, Kobayashi et al. present evidence that interdomain interactions between two of these mutation-enriched regions play a key role in the gating mechanism of RyR1.


2002 ◽  
Vol 278 (1) ◽  
pp. 444-453 ◽  
Author(s):  
Steven Reiken ◽  
Marta Gaburjakova ◽  
Silvia Guatimosim ◽  
Ana M. Gomez ◽  
Jeanine D'Armiento ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dorian V. Ziegler ◽  
David Vindrieux ◽  
Delphine Goehrig ◽  
Sara Jaber ◽  
Guillaume Collin ◽  
...  

AbstractCellular senescence is induced by stresses and results in a stable proliferation arrest accompanied by a pro-inflammatory secretome. Senescent cells accumulate during aging, promoting various age-related pathologies and limiting lifespan. The endoplasmic reticulum (ER) inositol 1,4,5-trisphosphate receptor, type 2 (ITPR2) calcium-release channel and calcium fluxes from the ER to the mitochondria are drivers of senescence in human cells. Here we show that Itpr2 knockout (KO) mice display improved aging such as increased lifespan, a better response to metabolic stress, less immunosenescence, as well as less liver steatosis and fibrosis. Cellular senescence, which is known to promote these alterations, is decreased in Itpr2 KO mice and Itpr2 KO embryo-derived cells. Interestingly, ablation of ITPR2 in vivo and in vitro decreases the number of contacts between the mitochondria and the ER and their forced contacts induce premature senescence. These findings shed light on the role of contacts and facilitated exchanges between the ER and the mitochondria through ITPR2 in regulating senescence and aging.


2009 ◽  
Vol 96 (3) ◽  
pp. 96a ◽  
Author(s):  
Que T. Ngo ◽  
Joshua T. Maxwell ◽  
Gregory A. Mignery ◽  
Wah Chiu ◽  
Steven J. Ludtke ◽  
...  

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