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Farthing EC, Henbest KC, Garcia‐Becerra T, Peaston KA, Williams LE. Dissecting the relative contribution of ECA3 and group 8/9 cation diffusion facilitators to manganese homeostasis in Arabidopsis thaliana. Plant Direct 2023; 7:e495. [PMID: 37228331 PMCID: PMC10202827 DOI: 10.1002/pld3.495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 03/14/2023] [Accepted: 03/27/2023] [Indexed: 05/27/2023]
Abstract
Manganese (Mn) is an essential micronutrient for plant growth but becomes toxic when present in excess. A number of Arabidopsis proteins are involved in Mn transport including ECA3, MTPs, and NRAMPs; however, their relative contributions to Mn homeostasis remain to be demonstrated. A major focus here was to clarify the importance of ECA3 in responding to Mn deficiency and toxicity using a range of mutants. We show that ECA3 localizes to the trans-Golgi and plays a major role in response to Mn deficiency with severe effects seen in eca3 nramp1 nramp2 under low Mn supply. ECA3 plays a minor role in Mn-toxicity tolerance, but only when the cis-Golgi-localized MTP11 is non-functional. We also use mutants and overexpressors to determine the relative contributions of MTP members to Mn homeostasis. The trans-Golgi-localized MTP10 plays a role in Mn-toxicity tolerance, but this is only revealed in mutants when MTP8 and MTP11 are non-functional and when overexpressed in mtp11 mutants. MTP8 and MTP10 confer greater Mn-toxicity resistance to the pmr1 yeast mutant than MTP11, and an important role for the first aspartate in the fifth transmembrane domain DxxxD motif is demonstrated. Overall, new insight into the relative influence of key transporters in Mn homeostasis is provided.
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Affiliation(s)
- Emily C. Farthing
- School of Biological SciencesUniversity of SouthamptonSouthamptonHampshireUK
| | - Kate C. Henbest
- School of Biological SciencesUniversity of SouthamptonSouthamptonHampshireUK
| | | | - Kerry A. Peaston
- School of Biological SciencesUniversity of SouthamptonSouthamptonHampshireUK
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Pedersen JT, Kanashova T, Dittmar G, Palmgren M. Isolation of native plasma membrane H +-ATPase (Pma1p) in both the active and basal activation states. FEBS Open Bio 2018; 8:774-783. [PMID: 29744292 PMCID: PMC5929935 DOI: 10.1002/2211-5463.12413] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 02/20/2018] [Accepted: 02/26/2018] [Indexed: 12/18/2022] Open
Abstract
The yeast plasma membrane H+‐ATPase Pma1p is a P‐type ATPase that energizes the yeast plasma membrane. Pma1p exists in two activation states: an autoinhibited basal state and an activated state. Here we show that functional and stable Pma1p can be purified in native form and reconstituted in artificial liposomes without altering its activation state. Acetylated tubulin has previously been reported to maintain Pma1p in the basal state but, as this protein was absent from the purified preparations, it cannot be an essential component of the autoinhibitory mechanism. Purification of and reconstitution of native Pma1p in both activation states opens up for a direct comparison of the transport properties of these states, which allowed us to confirm that the basal state has a low coupling ratio between ATP hydrolysis and protons pumped, whereas the activated state has a high coupling ratio. The ability to prepare native Pma1p in both activation states will facilitate further structural and biochemical studies examining the mechanism by which plasma membrane H+‐ATPases are autoinhibited.
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Affiliation(s)
- Jesper Torbøl Pedersen
- Department of Plant and Environmental Sciences University of Copenhagen Frederiksberg Denmark.,Present address: Institute of Environmental Medicine (IMM) Karolinska Institutet Stockholm Sweden
| | - Tamara Kanashova
- Mass Spectrometry Core Unit Max Delbrück Center for Molecular Medicine Berlin Germany
| | - Gunnar Dittmar
- Mass Spectrometry Core Unit Max Delbrück Center for Molecular Medicine Berlin Germany.,Proteome and Genome Research Laboratory Luxembourg Institute of Health Strassen Luxembourg
| | - Michael Palmgren
- Department of Plant and Environmental Sciences University of Copenhagen Frederiksberg Denmark
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Mattle D, Zhang L, Sitsel O, Pedersen LT, Moncelli MR, Tadini-Buoninsegni F, Gourdon P, Rees DC, Nissen P, Meloni G. A sulfur-based transport pathway in Cu+-ATPases. EMBO Rep 2015; 16:728-40. [PMID: 25956886 DOI: 10.15252/embr.201439927] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 03/31/2015] [Indexed: 11/09/2022] Open
Abstract
Cells regulate copper levels tightly to balance the biogenesis and integrity of copper centers in vital enzymes against toxic levels of copper. PIB -type Cu(+)-ATPases play a central role in copper homeostasis by catalyzing the selective translocation of Cu(+) across cellular membranes. Crystal structures of a copper-free Cu(+)-ATPase are available, but the mechanism of Cu(+) recognition, binding, and translocation remains elusive. Through X-ray absorption spectroscopy, ATPase activity assays, and charge transfer measurements on solid-supported membranes using wild-type and mutant forms of the Legionella pneumophila Cu(+)-ATPase (LpCopA), we identify a sulfur-lined metal transport pathway. Structural analysis indicates that Cu(+) is bound at a high-affinity transmembrane-binding site in a trigonal-planar coordination with the Cys residues of the conserved CPC motif of transmembrane segment 4 (C382 and C384) and the conserved Met residue of transmembrane segment 6 (M717 of the MXXXS motif). These residues are also essential for transport. Additionally, the studies indicate essential roles of other conserved intramembranous polar residues in facilitating copper binding to the high-affinity site and subsequent release through the exit pathway.
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Affiliation(s)
- Daniel Mattle
- Centre for Membrane Pumps in Cells and Disease - PUMPkin, Department of Molecular Biology and Genetics, Danish National Research Foundation Aarhus University, Aarhus C, Denmark Division of Chemistry and Chemical Engineering and Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA, USA
| | - Limei Zhang
- Division of Chemistry and Chemical Engineering and Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA, USA
| | - Oleg Sitsel
- Centre for Membrane Pumps in Cells and Disease - PUMPkin, Department of Molecular Biology and Genetics, Danish National Research Foundation Aarhus University, Aarhus C, Denmark
| | - Lotte Thue Pedersen
- Centre for Membrane Pumps in Cells and Disease - PUMPkin, Department of Molecular Biology and Genetics, Danish National Research Foundation Aarhus University, Aarhus C, Denmark
| | - Maria Rosa Moncelli
- Department of Chemistry 'Ugo Schiff', University of Florence, Sesto Fiorentino, Italy
| | | | - Pontus Gourdon
- Centre for Membrane Pumps in Cells and Disease - PUMPkin, Department of Molecular Biology and Genetics, Danish National Research Foundation Aarhus University, Aarhus C, Denmark
| | - Douglas C Rees
- Division of Chemistry and Chemical Engineering and Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA, USA
| | - Poul Nissen
- Centre for Membrane Pumps in Cells and Disease - PUMPkin, Department of Molecular Biology and Genetics, Danish National Research Foundation Aarhus University, Aarhus C, Denmark
| | - Gabriele Meloni
- Centre for Membrane Pumps in Cells and Disease - PUMPkin, Department of Molecular Biology and Genetics, Danish National Research Foundation Aarhus University, Aarhus C, Denmark Division of Chemistry and Chemical Engineering and Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA, USA
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