Allosteric modulation of the sarcoplasmic reticulum Ca2+ ATPase by thapsigargin via decoupling of functional motions

2019 ◽  
Vol 21 (39) ◽  
pp. 21991-21995 ◽  
Author(s):  
Noureldin Saleh ◽  
Yong Wang ◽  
Poul Nissen ◽  
Kresten Lindorff-Larsen
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Conformational Change ◽  
Nucleotide Binding ◽  
Allosteric Modulation ◽  
Cytoplasmic Domains ◽  
Transmembrane Regions

Thapsigargin binding to the Ca2+-ATPase SERCA induces a conformational change in the transmembrane regions without regulation of the cytoplasmic domains, and causes a conformational change in the cytoplasmic domains uncoupled from nucleotide binding.

scholarly journals Activation mechanism of ATP-sensitive K+ channels explored with real-time nucleotide binding

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Michael Puljung ◽  
Natascia Vedovato ◽  
Samuel Usher ◽  
Frances Ashcroft
Keyword(s):  
Conformational Change ◽  
Ionic Currents ◽  
Nucleotide Binding ◽  
Activation Mechanism ◽  
Time Resolved ◽  
K Channels ◽  
Novel Approach ◽  
Binding Event ◽  
Fluorescent Nucleotides

The response of ATP-sensitive K+ channels (KATP) to cellular metabolism is coordinated by three classes of nucleotide binding site (NBS). We used a novel approach involving labeling of intact channels in a native, membrane environment with a non-canonical fluorescent amino acid and measurement (using FRET with fluorescent nucleotides) of steady-state and time-resolved nucleotide binding to dissect the role of NBS2 of the accessory SUR1 subunit of KATP in channel gating. Binding to NBS2 was Mg2+-independent, but Mg2+ was required to trigger a conformational change in SUR1. Mutation of a lysine (K1384A) in NBS2 that coordinates bound nucleotides increased the EC50 for trinitrophenyl-ADP binding to NBS2, but only in the presence of Mg2+, indicating that this mutation disrupts the ligand-induced conformational change. Comparison of nucleotide-binding with ionic currents suggests a model in which each nucleotide binding event to NBS2 of SUR1 is independent and promotes KATP activation by the same amount.

scholarly journals Nucleotide binding triggers a conformational change of the CBS module of the magnesium transporter CNNM2 from a twisted towards a flat structure

2014 ◽  
Vol 464 (1) ◽  
pp. 23-34 ◽  
Author(s):  
María Ángeles Corral-Rodríguez ◽  
Marchel Stuiver ◽  
Guillermo Abascal-Palacios ◽  
Tammo Diercks ◽  
Iker Oyenarte ◽  
...  
Keyword(s):  
Conformational Change ◽  
Nucleotide Binding ◽  
Conformational Flexibility ◽  
Flat Structure ◽  
Magnesium Transporter

Nucleotide binding triggers a conformational change of the Bateman module of the magnesium transporter CNNM2. The hypomagnesaemia-causing mutation T568I impairs MgATP binding and limits the conformational flexibility of this protein module.

scholarly journals The nucleotide-binding domain of the Zn2+-transporting P-type ATPase from Escherichia coli carries a glycine motif that may be involved in binding of ATP

2004 ◽  
Vol 377 (1) ◽  
pp. 95-105 ◽  
Author(s):  
Juha OKKERI ◽  
Liisa LAAKKONEN ◽  
Tuomas HALTIA
Keyword(s):  
Escherichia Coli ◽  
Sarcoplasmic Reticulum ◽  
Binding Site ◽  
Molecular Model ◽  
Nucleotide Binding ◽  
Atp Binding ◽  
Atp Binding Site ◽  
Disease Mutations ◽  
Disease Protein ◽  
P Type

In P-type ATPases, the nucleotide-binding (N) domain is located in the middle of the sequence which folds into the phosphorylation (P) domain. The N domain of ZntA, a Zn2+-translocating P-type ATPase from Escherichia coli, is approx. 13% identical with the N domain of sarcoplasmic reticulum Ca2+-ATPase. None of the Ca2+-ATPase residues involved in binding of ATP are found in ZntA. However, the sequence G503SGIEAQV in the N domain of ZntA resembles the motif GxGxxG, which forms part of the ATP-binding site in protein kinases. This motif is also found in Wilson disease protein where several disease mutations cluster in it. In the present work, we have made a set of disease mutation analogues, including the mutants G503S (Gly503→Ser), G505R and A508F of ZntA. At low [ATP], these mutant ATPases are poorly phosphorylated. The phosphorylation defect of the mutants G503S and G505R can, however, be partially (G503S) or fully (G505R) compensated for by using a higher [ATP], suggesting that these mutations lower the affinity for ATP. In all three mutant ATPases, phosphorylation by Pi has become less sensitive to the presence of ATP, also consistent with the proposal that the Gly503 motif plays a role in ATP binding. In order to test this hypothesis, we have modelled the N domain of ZntA using the sarcoplasmic reticulum Ca2+-ATPase structure as a template. In the model, the Gly503 motif, as well as the residues Glu470 and His475, are located in the proximity of the ATP-binding site. In conclusion, the mutagenesis data and the molecular model are consistent with the idea that the two loops carrying the residues Glu470, His475, Gly503 and Gly505 play a role in ATP binding and activation.

scholarly journals Probing the Nucleotide Binding Sites of Sarcoplasmic Reticulum Atpase by Photoaffinity Labeling

1986 ◽  
Vol 49 (1) ◽  
pp. 108-109 ◽  
Author(s):  
S. Verjovski-Almeida ◽  
P.C. Carvalho-Alves ◽  
C.G. Oliveira ◽  
S.T. Ferreira
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Binding Sites ◽  
Photoaffinity Labeling ◽  
Nucleotide Binding ◽  
Nucleotide Binding Sites
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