Magnesium transport in Salmonella typhimurium: 28Mg2+ transport by the CorA, MgtA, and MgtB systems

Snavely, M D; Florer, Jane B.; Miller, Charles G.; Maguire, Michael E.

doi:10.1128/jb.171.9.4761-4766.1989

Cited by 216 publications

(311 citation statements)

References 13 publications

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“…The mechanism of Mg 2" transport across plasma membranes is best understood in bacteria where at least 3 different mechanisms have been described [16,17]. In mammalian systems, plasma membrane Mg 2. transport appears to involve Na ÷ and/or other ion co-transport [14,15,36,37].…”

Section: Discussionmentioning

confidence: 99%

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Regulation of Mg²⁺ uptake in isolated rat myocytes and hepatocytes by protein kinase C

1992

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A large Mg:* cell uptake against concentration gradients is stimulated in collagenase-disper~ed ra: myocytes by carbachol and in hepato~t~ by carbachol or vasoprcssin. The signalling pathway(s) responsible for this stimulation o1" Mg ~-+ uptake was inv.+stigated by using various activators or inhibitors of protein kinase C (PKC) and by correlatin/~ Mg :+ uptake with cell PKC activity and cAMP content. In both cell preparations, the dir~.,ct stimulation of PKC by diaeylglycerol analogs or phorbol esters reproduce the same pattern of MS -+" uptake as that induced by carbachol or vasopressin. These data indicate that the activation of PKC is responsible for a stimulation of Mg:" uptake by myocytes or hepatocytes, whereas increase in cAMP in these cells stimulates Mg a' release.

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Section: Discussionmentioning

confidence: 99%

“…Evidence for a Na+-Mg 2. exchanger has been clearly documented in the literature [14,15], and a novel P-class ATPase inwardly transporting Mg 2. has recently been reported in bacteria [16,17].…”

Section: A Bbrevandtions: H Epes 4-(2-hydroxymethyl)l Piperazine Ethamentioning

confidence: 99%

Regulation of Mg²⁺ uptake in isolated rat myocytes and hepatocytes by protein kinase C

1992

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“…As mentioned above, CorA is a Mg 2+ transporter, which usually mediates Mg 2+ uptake but in certain circumstances can also act as a Mg 2+ exporter (Snavely et al, 1989). CorA has been crystallized and shown to form a homopentamer (Payandesh and Pai, 2006).…”

Section: A B C E D Fmentioning

confidence: 99%

Common Functions or Only Phylogenetically Related? The Large Family of PLAC8 Motif-Containing/PCR Genes

Song

Hörtensteiner

Tomioka

et al. 2011

Molecules and Cells

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“…This must be related to the way in which the Mg 2+ ion interacts with the transporter. The problem may be that Mg 2+ prefers to be hexacoordinated and probably remains so throughout the conduction process 19 . Hence, as the hydrated Mg 2+ ion enters the conduction pathway, the number of available coordination sites would not match the five-fold symmetry of the CorA selectivity filter.…”

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confidence: 99%

“…However, the visible structural features of the CorA transporter, as well as the unique chemistry of Mg 2+ , limit the mechanisms by which it can be highly selective for the ion. Sieving for hydrated cations is an insufficient explanation because the hydrated radius of magnesium is the largest of all biological cations ( 5 Å) 19 . Based on size alone, Ca 2+ would be predicted to be transported, but it is neither a substrate nor an inhibitor of CorA 3,20 .…”

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confidence: 99%

Crystal structure of the CorA Mg2+ transporter

Лунин

Dobrovetsky²,

Khutoreskaya³

et al. 2006

Nature

236

301

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The magnesium ion, Mg 2+ , is essential for myriad biochemical processes and remains the only major biological ion whose transport mechanisms remain unknown. The CorA family of magnesium transporters is the primary Mg 2+ uptake system of most prokaryotes 1-3 and a functional homologue of the eukaryotic mitochondrial magnesium transporter 4 . Here we determine crystal structures of the full-length Thermotoga maritima CorA in an apparent closed state and its isolated cytoplasmic domain at 3.9 Å and 1.85Å resolution, respectively. The transporter is a funnel-shaped homopentamer with two transmembrane helices per monomer. The channel is formed by an inner group of five helices and putatively gated by bulky hydrophobic residues. The large cytoplasmic domain forms a funnel whose wide mouth points into the cell and whose walls are formed by five long helices that are extensions of the transmembrane helices. The cytoplasmic neck of the pore is surrounded, on the outside of the funnel, by a ring of highly conserved positively charged residues. Two negatively charged helices in the cytoplasmic domain extend back towards the membrane on the outside of the funnel and abut the ring of positive charge. An apparent Mg 2+ ion was bound between monomers at a conserved site in the cytoplasmic domain, suggesting a mechanism to link gating of the pore to the intra-cellular concentration of Mg 2+ . The CorA magnesium transporter is a homopentamer with fivefold symmetry about a central pore and can be divided into three parts (Fig. 1). A carboxy-terminal transmembrane domain comprises two transmembrane helices from each monomer (Fig. 2). The middle portion resembles a funnel, narrow at the entrance ( 5 Å) and wide at the mouth ( 20Å), that is formed largely by a long -helix extension of the inner transmembrane helix. Finally, a large cytoplasmic domain lies exterior to the funnel.The cytoplasmic domain of CorA is a seven-stranded parallel/antiparallel -sheet ( 2 1 3 7 6 5 4 ) sandwiched between two sets of -helices ( 1, 2, 3) and ( 4, 5, 6) ( Fig. 1). The domain fold is unlike all other known structures of ion channels or transporters and constitutes a new protein fold (see Supplementary Information). This domain, solved in its soluble form at 1.85 Å resolution ( Supplementary Fig. S1), is linked to the transmembrane helices by the long 7 helix (residues 251-312), termed the stalk helix. The stalk helix kinks as it enters the membrane, extends through the membrane, forms the first transmembrane helix (TM1; residues 293-312) and harbours the 'YGMNF' signature sequence of CorA (residues 311-315) 5,6 ( Fig. 2 and Supplementary Fig. S2). The five TM1 helices (residues 293-312) form the pore. After a short extracellular seven-amino-acid loop, the TM2 helix (residues 326-345) returns back to the cytoplasm and ends in a highly conserved C-terminal KKKKWL motif (Fig. 3). In the current structure, neither the extracellular loop nor the final two amino acids could be resolved.The cytoplasmic domain shows the lowest sequence conservati...

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Magnesium transport in Salmonella typhimurium: 28Mg2+ transport by the CorA, MgtA, and MgtB systems

Cited by 216 publications

References 13 publications

Regulation of Mg²⁺ uptake in isolated rat myocytes and hepatocytes by protein kinase C

Regulation of Mg²⁺ uptake in isolated rat myocytes and hepatocytes by protein kinase C

Common Functions or Only Phylogenetically Related? The Large Family of PLAC8 Motif-Containing/PCR Genes

Crystal structure of the CorA Mg2+ transporter

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Magnesium transport in Salmonella typhimurium: 28Mg2+ transport by the CorA, MgtA, and MgtB systems

Cited by 216 publications

References 13 publications

Regulation of Mg2+ uptake in isolated rat myocytes and hepatocytes by protein kinase C

Regulation of Mg2+ uptake in isolated rat myocytes and hepatocytes by protein kinase C

Common Functions or Only Phylogenetically Related? The Large Family of PLAC8 Motif-Containing/PCR Genes

Crystal structure of the CorA Mg2+ transporter

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Regulation of Mg²⁺ uptake in isolated rat myocytes and hepatocytes by protein kinase C

Regulation of Mg²⁺ uptake in isolated rat myocytes and hepatocytes by protein kinase C