The mitochondrial calcium uniporter is a highly selective calcium channel distributed broadly across eukaryotes but absent in the yeast Saccharomyces cerevisiae. The molecular components of the human uniporter holocomplex (uniplex) have been identified recently. The uniplex consists of three membrane-spanning subunits--mitochondrial calcium uniporter (MCU), its paralog MCUb, and essential MCU regulator (EMRE)--and two soluble regulatory components--MICU1 and its paralog MICU2. The minimal components sufficient for in vivo uniporter activity are unknown. Here we consider Dictyostelium discoideum (Dd), a member of the Amoebazoa outgroup of Metazoa and Fungi, and show that it has a highly simplified uniporter machinery. We show that D. discoideum mitochondria exhibit membrane potential-dependent calcium uptake compatible with uniporter activity, and also that expression of DdMCU complements the mitochondrial calcium uptake defect in human cells lacking MCU or EMRE. Moreover, expression of DdMCU in yeast alone is sufficient to reconstitute mitochondrial calcium uniporter activity. Having established yeast as an in vivo reconstitution system, we then reconstituted the human uniporter. We show that coexpression of MCU and EMRE is sufficient for uniporter activity, whereas expression of MCU alone is insufficient. Our work establishes yeast as a powerful in vivo reconstitution system for the uniporter. Using this system, we confirm that MCU is the pore-forming subunit, define the minimal genetic elements sufficient for metazoan and nonmetazoan uniporter activity, and provide valuable insight into the evolution of the uniporter machinery.
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http://dx.doi.org/10.1073/pnas.1400514111 | DOI Listing |
PLoS Pathog
January 2025
Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, MOE International Joint Collaborative Research Laboratory for Animal Health & Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
Mitochondria, recognized as the "powerhouse" of cells, play a vital role in generating cellular energy through dynamic processes such as fission and fusion. Viruses have evolved mechanisms to hijack mitochondrial function for their survival and proliferation. Here, we report that infection with the swine arterivirus porcine reproductive and respiratory syndrome virus (PRRSV), manipulates mitochondria calcium ions (Ca2+) to induce mitochondrial fission and mitophagy, thereby reprogramming cellular energy metabolism to facilitate its own replication.
View Article and Find Full Text PDFEur J Neurosci
January 2025
Université Grenoble Alpes, CNRS, LIPhy, Grenoble, France.
Staining brain slices with acetoxymethyl ester (AM) Ca dyes is a straightforward procedure to load multiple cells, and Fluo-4 is a commonly used high-affinity indicator due to its very large dynamic range. It has been shown that this dye preferentially stains glial cells, providing slow and large Ca transients, but it is questionable whether and at which temporal resolution it can also report Ca transients from neuronal cells. Here, by electrically stimulating mouse hippocampal slices, we resolved fast neuronal signals corresponding to 1%-3% maximal fluorescence changes.
View Article and Find Full Text PDFBehav Neurol
January 2025
Laboratory of Neurobiology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China.
Astrocytes are the primary cell type in the central nervous system, responsible for maintaining the stability of the brain's internal environment and supporting neuronal functions. Researches have demonstrated the close relationship between astrocytes and the pathophysiology and etiology of major depressive disorder. However, the regulatory mechanisms of astrocytes during depression remain unclear.
View Article and Find Full Text PDFJ Struct Biol X
June 2025
Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, USA.
We investigated several small viral proteins that reside and function in cellular membranes. These proteins belong to the viroporin family because they assemble into ion-conducting oligomers. However, despite forming similar oligomeric structures with analogous functions, these proteins have diverse amino acid sequences.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Inner Mongolia Key Laboratory of Chemistry and Physics of Rare Earth Materials, School of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, P. R. China.
Metal-organic frameworks (MOFs) with well-ordered channels are considered ideal solid-state electrolytes (SSEs) for lithium ionic conductors and are expected to be utilized in all-solid-state Li-ion batteries. However, the outstanding Li conductivity of MOFs, especially the properties at low temperatures, has become a crucial problem to overcome. Herein, a breakthrough is first realized to cope with this challenge a strategy of introducing fluoro-substituted bridging ligands in MOFs.
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