Powered by the mitochondrial membrane potential,Ca2+ permeates the mitochondria via a Ca2+ channel termed Ca2+ uniporter and is pumped out by a Na+/Ca2+ exchanger,both of which are located on the inner mitochondrial m...Powered by the mitochondrial membrane potential,Ca2+ permeates the mitochondria via a Ca2+ channel termed Ca2+ uniporter and is pumped out by a Na+/Ca2+ exchanger,both of which are located on the inner mitochondrial membrane.Mitochondrial Ca2+ transients are critical for metabolic activity and regulating global Ca2+ responses.On the other hand,failure to control mitochondrial Ca2+ is a hallmark of ischemic and neurodegenerative diseases.Despite their importance,identifying the uniporter and exchanger remains elusive and their inhibitors are non-specific.This review will focus on the mitochondrial exchanger,initially describing how it was molecularly identified and linked to a novel member of the Na+/Ca2+ exchanger superfamily termed NCLX.Molecular control of NCLX expression provides a selective tool to determine its physiological role in a variety of cell types.In lymphocytes,NCLX is essential for refilling the endoplasmic reticulum Ca2+ stores required for antigen-dependent signaling.Communication of NCLX with the store-operated channel in astroglia controls Ca2+ influx and thereby neuro-transmitter release and cell proliferation.The refilling of the Ca2+ stores in the sarcoplasmic reticulum,which is controlled by NCLX,determines the frequency of action potential and Ca2+ transients in cardiomyocytes.NCLX is emerging as a hub for integrating glucose-dependent Na+ and Ca2+ signaling in pancreatic β cells,and the specific molecular control of NCLX expression resolved the controversy regarding its role in neurons and β cells.Future studies on an NCLX knockdown mouse model and identification of human NCLX mutations are expected to determine the role of mitochondrial Ca2+ efflux in organ activity and whether NCLX inactivation is linked to ischemic and/or neurodegenerative syndromes.Structure-function analysis and protein analysis will identify the NCLX mode of regulation and its partners in the inner membrane of the mitochondria.展开更多
The relationship between mitochondrial Ca2+ transport and permeability transition pore (PTP) opening as well as the effects of mitochondrial energetic status on mitochondrial Ca2+ transport and PTP opening were studie...The relationship between mitochondrial Ca2+ transport and permeability transition pore (PTP) opening as well as the effects of mitochondrial energetic status on mitochondrial Ca2+ transport and PTP opening were studied. The results showed that the calcium-induced calcium release from mitochondria (mClCR) induced PTP opening. Inhibitors for electron transport of respiratory chain inhibited mClCR and PTP opening. Partial recovery of electron transport in respiratory chain resulted in partial recovery of mClCR and PTP opening. mClCR and PTP opening were also inhibited by CCCP which eliminated transmembrane proton gradient. The results indicated that mitochondrial Ca2+ transport and PTP opening are largely dependent on electron transport and energy coupling.展开更多
Plant mineral nutrition is essential for crop yields and human health.However,the uneven distribution of mineral elements over time and space leads to a lack or excess of available mineral elements in plants.Among the...Plant mineral nutrition is essential for crop yields and human health.However,the uneven distribution of mineral elements over time and space leads to a lack or excess of available mineral elements in plants.Among the essential nutrients,calcium(Ca^(2+))stands out as a prominent second messenger that plays crucial roles in response to extracellular stimuli in all eukaryotes.Distinct Ca^(2+)signatures with unique parameters are induced by different stresses and deciphered by various Ca^(2+)sensors.Recent research on the participation of Ca^(2+)signaling in regulation of mineral elements has made great progress.In this review,we focus on the impact of Ca^(2+)signaling on plant mineral uptake and detoxification.Specifically,we emphasize the significance of Ca^(2+)signaling for regulation of plant mineral nutrition and delve into key points and novel avenues for future investigations,aiming to offer new insights into plant ion homeostasis.展开更多
文摘Powered by the mitochondrial membrane potential,Ca2+ permeates the mitochondria via a Ca2+ channel termed Ca2+ uniporter and is pumped out by a Na+/Ca2+ exchanger,both of which are located on the inner mitochondrial membrane.Mitochondrial Ca2+ transients are critical for metabolic activity and regulating global Ca2+ responses.On the other hand,failure to control mitochondrial Ca2+ is a hallmark of ischemic and neurodegenerative diseases.Despite their importance,identifying the uniporter and exchanger remains elusive and their inhibitors are non-specific.This review will focus on the mitochondrial exchanger,initially describing how it was molecularly identified and linked to a novel member of the Na+/Ca2+ exchanger superfamily termed NCLX.Molecular control of NCLX expression provides a selective tool to determine its physiological role in a variety of cell types.In lymphocytes,NCLX is essential for refilling the endoplasmic reticulum Ca2+ stores required for antigen-dependent signaling.Communication of NCLX with the store-operated channel in astroglia controls Ca2+ influx and thereby neuro-transmitter release and cell proliferation.The refilling of the Ca2+ stores in the sarcoplasmic reticulum,which is controlled by NCLX,determines the frequency of action potential and Ca2+ transients in cardiomyocytes.NCLX is emerging as a hub for integrating glucose-dependent Na+ and Ca2+ signaling in pancreatic β cells,and the specific molecular control of NCLX expression resolved the controversy regarding its role in neurons and β cells.Future studies on an NCLX knockdown mouse model and identification of human NCLX mutations are expected to determine the role of mitochondrial Ca2+ efflux in organ activity and whether NCLX inactivation is linked to ischemic and/or neurodegenerative syndromes.Structure-function analysis and protein analysis will identify the NCLX mode of regulation and its partners in the inner membrane of the mitochondria.
文摘The relationship between mitochondrial Ca2+ transport and permeability transition pore (PTP) opening as well as the effects of mitochondrial energetic status on mitochondrial Ca2+ transport and PTP opening were studied. The results showed that the calcium-induced calcium release from mitochondria (mClCR) induced PTP opening. Inhibitors for electron transport of respiratory chain inhibited mClCR and PTP opening. Partial recovery of electron transport in respiratory chain resulted in partial recovery of mClCR and PTP opening. mClCR and PTP opening were also inhibited by CCCP which eliminated transmembrane proton gradient. The results indicated that mitochondrial Ca2+ transport and PTP opening are largely dependent on electron transport and energy coupling.
基金supported by the National Natural Science Foundation of China(32222008 to C.W.)the China Postdoctoral Science Foundation(2023M732883 to C.J.).
文摘Plant mineral nutrition is essential for crop yields and human health.However,the uneven distribution of mineral elements over time and space leads to a lack or excess of available mineral elements in plants.Among the essential nutrients,calcium(Ca^(2+))stands out as a prominent second messenger that plays crucial roles in response to extracellular stimuli in all eukaryotes.Distinct Ca^(2+)signatures with unique parameters are induced by different stresses and deciphered by various Ca^(2+)sensors.Recent research on the participation of Ca^(2+)signaling in regulation of mineral elements has made great progress.In this review,we focus on the impact of Ca^(2+)signaling on plant mineral uptake and detoxification.Specifically,we emphasize the significance of Ca^(2+)signaling for regulation of plant mineral nutrition and delve into key points and novel avenues for future investigations,aiming to offer new insights into plant ion homeostasis.
