Evidence for receptor-mediated calcium entry and refilling of intracellular calcium stores in FRTL-5 rat thyroid cells

1992 ◽  
Vol 150 (1) ◽  
pp. 90-98 ◽  
Author(s):  
Kid Törnquist
2000 ◽  
Vol 149 (4) ◽  
pp. 793-798 ◽  
Author(s):  
Malcolm A. Leissring ◽  
Yama Akbari ◽  
Christopher M. Fanger ◽  
Michael D. Cahalan ◽  
Mark P. Mattson ◽  
...  

Dysregulation of calcium signaling has been causally implicated in brain aging and Alzheimer's disease. Mutations in the presenilin genes (PS1, PS2), the leading cause of autosomal dominant familial Alzheimer's disease (FAD), cause highly specific alterations in intracellular calcium signaling pathways that may contribute to the neurodegenerative and pathological lesions of the disease. To elucidate the cellular mechanisms underlying these disturbances, we studied calcium signaling in fibroblasts isolated from mutant PS1 knockin mice. Mutant PS1 knockin cells exhibited a marked potentiation in the amplitude of calcium transients evoked by agonist stimulation. These cells also showed significant impairments in capacitative calcium entry (CCE, also known as store-operated calcium entry), an important cellular signaling pathway wherein depletion of intracellular calcium stores triggers influx of extracellular calcium into the cytosol. Notably, deficits in CCE were evident after agonist stimulation, but not if intracellular calcium stores were completely depleted with thapsigargin. Treatment with ionomycin and thapsigargin revealed that calcium levels within the ER were significantly increased in mutant PS1 knockin cells. Collectively, our findings suggest that the overfilling of calcium stores represents the fundamental cellular defect underlying the alterations in calcium signaling conferred by presenilin mutations.


1995 ◽  
Vol 311 (1) ◽  
pp. 41-44 ◽  
Author(s):  
C C Petersen ◽  
M J Berridge ◽  
M F Borgese ◽  
D L Bennett

Capacitative calcium entry is a major pathway through which intracellular calcium stores are refilled after stimulation. It has been suggested that the protein encoded by the transient receptor potential (trp) gene expressed in Drosophila photoreceptors may be homologous with capacitative calcium entry channels. Expression of the trp gene product in Xenopus oocytes led to significant increases in calcium entry only when the intracellular calcium stores were depleted. Previous investigations have found trp to be uniquely expressed in Drosophila photoreceptors, but PCR cloning shows that homologous proteins exist in Calliphora, mouse brain and Xenopus oocytes. It is thus possible that capacitative calcium entry in Xenopus oocytes is mediated by a homologue of trp.


2004 ◽  
Vol 88 (6) ◽  
pp. 1361-1372 ◽  
Author(s):  
Yaxiong Yang ◽  
Gregory A. Kinney ◽  
William J. Spain ◽  
John C. S. Breitner ◽  
David G. Cook

2007 ◽  
Vol 18 (8) ◽  
pp. 3119-3130 ◽  
Author(s):  
Natalia Cheshenko ◽  
Wen Liu ◽  
Lisa M. Satlin ◽  
Betsy C. Herold

Herpes simplex viruses (HSV) harness cellular calcium signaling pathways to facilitate viral entry. Confocal microscopy and small interfering RNA (siRNA) were used to identify the source of the calcium and to dissect the requisite viral–cell interactions. Binding of HSV to human epithelial cells induced no calcium response, but shifting the cells to temperatures permissive for penetration triggered increases in plasma membrane calcium followed by a global release of intracellular calcium. Transfection with siRNA targeting the proteoglycan syndecan-2 blocked viral binding and abrogated any calcium response. Transfection with siRNA targeting nectin-1, a glycoprotein D receptor, also prevented both membrane and intracellular calcium responses. In contrast, the membrane response was preserved after transfection with siRNA targeting integrinαv, a novel glycoprotein H receptor. The membrane response, however, was not sufficient for viral entry, which required interactions with integrinαv and release of inositol-triphosphate receptor-dependent intracellular calcium stores. Thus, calcium plays a critical, complex role in HSV entry.


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