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Wu M, Wu C, Song T, Pan K, Wang Y, Liu Z. Structure and transport mechanism of the human calcium pump SPCA1. Cell Res 2023; 33:533-545. [PMID: 37258749 PMCID: PMC10313705 DOI: 10.1038/s41422-023-00827-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 05/08/2023] [Indexed: 06/02/2023] Open
Abstract
Secretory-pathway Ca2+-ATPases (SPCAs) play critical roles in maintaining Ca2+ homeostasis, but the exact mechanism of SPCAs-mediated Ca2+ transport remains unclear. Here, we determined six cryo-electron microscopy (cryo-EM) structures of human SPCA1 (hSPCA1) in a series of intermediate states, revealing a near-complete conformational cycle. With the aid of molecular dynamics simulations, these structures offer a clear structural basis for Ca2+ entry and release in hSPCA1. We found that hSPCA1 undergoes unique conformational changes during ATP binding and phosphorylation compared to other well-studied P-type II ATPases. In addition, we observed a conformational distortion of the Ca2+-binding site induced by the separation of transmembrane helices 4L and 6, unveiling a distinct Ca2+ release mechanism. Particularly, we determined a structure of the long-sought CaE2P state of P-type IIA ATPases, providing valuable insights into the Ca2+ transport cycle. Together, these findings enhance our understanding of Ca2+ transport by hSPCA1 and broaden our knowledge of P-type ATPases.
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Affiliation(s)
- Mengqi Wu
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Cang Wu
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Tiefeng Song
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Kewu Pan
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Yong Wang
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China.
- The Provincial International Science and Technology Cooperation Base on Engineering Biology, International Campus of Zhejiang University, Haining, Zhejiang, China.
| | - Zhongmin Liu
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China.
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Zhou W, Yan X, Zhai Y, Liu H, Guan L, Qiao Y, Jiang J, Peng L. Phillygenin ameliorates nonalcoholic fatty liver disease via TFEB-mediated lysosome biogenesis and lipophagy. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2022; 103:154235. [PMID: 35716542 DOI: 10.1016/j.phymed.2022.154235] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 05/21/2022] [Accepted: 06/01/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Lipophagy is an autophagic process, which delivers the intracellular lipid droplets to the lysosomes for degradation. Recent studies revealed that the impairment of lysosomal biogenesis and autophagic flux led to dysregulation of lipophagy in hepatocytes, which exacerbated the development of nonalcoholic fatty liver disease (NAFLD). Therefore, agents restoring autophagic flux and lipophagy in hepatocytes may have therapeutic potential against this increasingly prevalent disease. Phillygenin (PHI), a lignin extracted from Forsythia suspense, exerts hepatoprotective and anti-inflammatory effects. However, the effect of PHI on NAFLD remains unknown. PURPOSE This study aimed to investigate the protective effect of PHI on NAFLD and elucidate the underlying mechanism. METHODS The effects of PHI were examined in palmitate (PA)-stimulated AML12 cells and primary hepatocytes, as well as in NAFLD mice induced by a high-fat diet (HFD). We also used transcription factor EB (TFEB) knockdown hepatocytes and hepatocyte-specific TFEB knockout (TFEBΔhep) mice for mechanistic studies. In vivo and in vitro studies were performed using western blots, immunofluorescence techniques, and transmission electron microscopy. RESULTS Our results indicated that autophagic flux and lysosome biogenesis in PA-stimulated hepatocytes were impaired. PHI alleviated lipid deposition by increasing lysosomal biogenesis and autophagic flux. It also stimulated the release of endoplasmic reticulum Ca2+ to activate calcineurin, which regulated TFEB dephosphorylation and nuclear translocation, and promoted lysosomal biogenesis. In addition, PHI blocked the NLRP3 inflammasome pathway and improved hepatocyte inflammation in an autophagy-dependent manner. Consistent with the in vitro results, PHI improved hepatic steatosis and inflammation in HFD mice, but these beneficial effects were eliminated in hepatocyte-specific TFEB knockout mice. CONCLUSION Despite PHI has been reported to have anti-hepatic fibrosis effects, whether it has a hepatoprotective effects against NAFLD and the underlying molecular mechanism remain unclear. Herein, we found that PHI restored lipophagy and suppressed lipid accumulation and inflammation by regulating the Ca2+-calcineurin-TFEB axis in hepatocytes. Thus, PHI represents a therapeutic candidate for the treatment of NAFLD.
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Affiliation(s)
- Wenling Zhou
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China; College of Life Sciences, Hebei University, Baoding 071002, China
| | - Xu Yan
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China; College of Life Sciences, Hebei University, Baoding 071002, China
| | - Yuanyuan Zhai
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China; College of Life Sciences, Hebei University, Baoding 071002, China
| | - Hao Liu
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
| | - Lingling Guan
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
| | - Yuan Qiao
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
| | - Jizhi Jiang
- College of Life Sciences, Hebei University, Baoding 071002, China.
| | - Liang Peng
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China.
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Wu C, Guo WB, Liu YY, Yang L, Miao AJ. Molecular mechanisms underlying the calcium-mediated uptake of hematite nanoparticles by the ciliate Tetrahymena thermophila. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 288:117749. [PMID: 34329064 DOI: 10.1016/j.envpol.2021.117749] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/21/2021] [Accepted: 07/06/2021] [Indexed: 06/13/2023]
Abstract
In aquatic ecosystems, the calcium (Ca) concentration varies greatly. It is well known that Ca affects the aggregation of nanoparticles (NPs) and thus their bioaccumulation. Nevertheless, Ca also plays critical roles in various biological processes, whose effects on NP accumulation in aquatic organisms remain unclear. In this study, the effects of Ca on the uptake of polyacrylate-coated hematite NPs (HemNPs) by the aquatic ciliate Tetrahymena thermophila were investigated. At all of the tested Ca concentrations, HemNPs were well dispersed in the experimental medium, excluding the possibility of Ca to influence HemNP bioaccumulation by aggregating the NPs. Instead, Ca was shown to induce the clathrin-mediated endocytosis and phagocytosis of HemNPs. Manipulation of the Ca speciation in the experimental medium as well as the influx and intracellular availability of Ca in T. thermophila indicated that HemNP uptake was regulated by the intracellular Ca level. The results of the proteomics analyses further showed that the binding of intracellular Ca to calmodulin altered the activity of proteins involved in clathrin-mediated endocytosis (calcineurin and dynamin) and phagocytosis (actin). Overall, the biologically inductive effects of Ca on NP accumulation in aquatic organisms should be considered when evaluating the environmental risks of NPs.
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Affiliation(s)
- Chao Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province, 210023, China
| | - Wen-Bo Guo
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province, 210023, China
| | - Yue-Yue Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province, 210023, China
| | - Liuyan Yang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province, 210023, China
| | - Ai-Jun Miao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province, 210023, China.
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Zhao M, Chen J, Jin H, Qi Z. Extracellular Ca 2+ induces desensitized cytosolic Ca 2+ rise sensitive to phospholipase C inhibitor which suppresses root growth with Ca 2+ dependence. JOURNAL OF PLANT PHYSIOLOGY 2020; 252:153190. [PMID: 32688165 DOI: 10.1016/j.jplph.2020.153190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 05/04/2020] [Accepted: 05/09/2020] [Indexed: 06/11/2023]
Abstract
Calcium (Ca) is an essential element for all organisms. In animal cells, the plasma membrane-localized Ca receptor CaSR coupled to a phospholipase C (PLC)-dependent signaling cascade monitors extracellular Ca2+ concentrations ([Ca2+]ext) and responds with increases in cytosolic calcium concentrations ([Ca2+]cyt). Plant roots encounter variable soil conditions, but how they sense changes in [Ca2+]ext is largely unknown. In this study, we demonstrate that increasing [Ca2+]ext evokes a transient increase in [Ca2+] in the cytosol, mitochondria, and nuclei of Arabidopsis thaliana root cells. These increases were strongly desensitized to repeat applications of [Ca2+]ext, a typical feature of receptor-mediated cellular signaling in animal and plant cells. Treatment with gadolinium (Gd3+), a CaSR activator in animal cells, induced concentration-dependent increases in [Ca2+]cyt in roots, which showed self-desensitization and cross-desensitization to [Ca2+]ext-induced increases in [Ca2+]cyt (EICC). EICC was sensitive to extracellular H+, K+, Na+, and Mg2+ levels. Treatment with the PLC inhibitor neomycin suppressed EICC and Ca accumulation in roots. The inhibitory effect of neomycin on root elongation was fully rescued by increasing [Ca2+]ext but not [Mg2+] or [K+] in the growth medium. These results suggest that [Ca2+]ext and the movement of Ca2+ into the cytosol of plant roots are regulated by a receptor-mediated signaling pathway involving PLC.
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Affiliation(s)
- Man Zhao
- Key Laboratory of Forage and Endemic Crop Biotechnology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot, 010071, PR China; State Key Laboratory of Reproductive Regulatory and Breeding of Grassland Livestock, Inner Mongolia University, Hohhot, 010071, PR China
| | - Jianhua Chen
- Key Laboratory of Forage and Endemic Crop Biotechnology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot, 010071, PR China; State Key Laboratory of Reproductive Regulatory and Breeding of Grassland Livestock, Inner Mongolia University, Hohhot, 010071, PR China
| | - Huiqing Jin
- Research Centre for Horticultural Science and Technology of Hohhot, Hohhot, 010020, PR China
| | - Zhi Qi
- Key Laboratory of Forage and Endemic Crop Biotechnology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot, 010071, PR China; State Key Laboratory of Reproductive Regulatory and Breeding of Grassland Livestock, Inner Mongolia University, Hohhot, 010071, PR China.
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Aguayo-Ortiz R, Espinoza-Fonseca LM. Linking Biochemical and Structural States of SERCA: Achievements, Challenges, and New Opportunities. Int J Mol Sci 2020; 21:ijms21114146. [PMID: 32532023 PMCID: PMC7313052 DOI: 10.3390/ijms21114146] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/05/2020] [Accepted: 06/08/2020] [Indexed: 02/07/2023] Open
Abstract
Sarcoendoplasmic reticulum calcium ATPase (SERCA), a member of the P-type ATPase family of ion and lipid pumps, is responsible for the active transport of Ca2+ from the cytoplasm into the sarcoplasmic reticulum lumen of muscle cells, into the endoplasmic reticulum (ER) of non-muscle cells. X-ray crystallography has proven to be an invaluable tool in understanding the structural changes of SERCA, and more than 70 SERCA crystal structures representing major biochemical states (defined by bound ligand) have been deposited in the Protein Data Bank. Consequently, SERCA is one of the best characterized components of the calcium transport machinery in the cell. Emerging approaches in the field, including spectroscopy and molecular simulation, now help integrate and interpret this rich structural information to understand the conformational transitions of SERCA that occur during activation, inhibition, and regulation. In this review, we provide an overview of the crystal structures of SERCA, focusing on identifying metrics that facilitate structure-based categorization of major steps along the catalytic cycle. We examine the integration of crystallographic data with different biophysical approaches and computational methods to link biochemical and structural states of SERCA that are populated in the cell. Finally, we discuss the challenges and new opportunities in the field, including structural elucidation of functionally important and novel regulatory complexes of SERCA, understanding the structural basis of functional divergence among homologous SERCA regulators, and bridging the gap between basic and translational research directed toward therapeutic modulation of SERCA.
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Allosteric drugs and mutations: chances, challenges, and necessity. Curr Opin Struct Biol 2020; 62:149-157. [DOI: 10.1016/j.sbi.2020.01.010] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 01/16/2020] [Indexed: 12/22/2022]
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