NEM modification prevents high-affinity ATP binding to the first nucleotide binding fold of the sulphonylurea receptor, SUR1.

Pancreatic beta-cell ATP-sensitive potassium channels, composed of SUR1 and Kir6.2 subunits, serve as a sensor for intracellular nucleotides and regulate glucose-induced insulin secretion. To learn more about the interaction of SUR1 with nucleotides, we examined the effect of N-ethylmaleimide (NEM)...

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Main Authors: Matsuo, M, Tucker, S, Ashcroft, F, Amachi, T, Ueda, K
Format: Journal article
Language:English
Published: 1999
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author Matsuo, M
Tucker, S
Ashcroft, F
Amachi, T
Ueda, K
author_facet Matsuo, M
Tucker, S
Ashcroft, F
Amachi, T
Ueda, K
author_sort Matsuo, M
collection OXFORD
description Pancreatic beta-cell ATP-sensitive potassium channels, composed of SUR1 and Kir6.2 subunits, serve as a sensor for intracellular nucleotides and regulate glucose-induced insulin secretion. To learn more about the interaction of SUR1 with nucleotides, we examined the effect of N-ethylmaleimide (NEM) modification. Photoaffinity labeling of SUR1 with 5 microM 8-azido-[alpha-32P]ATP or 8-azido-[gamma-32P]ATP was inhibited by NEM with Ki of 1.8 microM and 2.4 microM, and Hill coefficients of 0.94 and 1.1, respectively. However, when the cysteine residue in the Walker A motif of the first nucleotide binding fold (NBF1) of SUR1 was replaced with serine (C717S), photoaffinity labeling was not inhibited by 100 microM NEM. These results suggest that NBF1 of SUR1 has a NEM-sensitive structure similar to that of NBF1 of MDR1, a multidrug transporter, and confirm NBF1 as the high-affinity ATP binding site on SUR1.
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spelling oxford-uuid:3d77a3c6-d18c-4305-bb3c-db29cf5678382022-03-26T14:19:27ZNEM modification prevents high-affinity ATP binding to the first nucleotide binding fold of the sulphonylurea receptor, SUR1.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:3d77a3c6-d18c-4305-bb3c-db29cf567838EnglishSymplectic Elements at Oxford1999Matsuo, MTucker, SAshcroft, FAmachi, TUeda, KPancreatic beta-cell ATP-sensitive potassium channels, composed of SUR1 and Kir6.2 subunits, serve as a sensor for intracellular nucleotides and regulate glucose-induced insulin secretion. To learn more about the interaction of SUR1 with nucleotides, we examined the effect of N-ethylmaleimide (NEM) modification. Photoaffinity labeling of SUR1 with 5 microM 8-azido-[alpha-32P]ATP or 8-azido-[gamma-32P]ATP was inhibited by NEM with Ki of 1.8 microM and 2.4 microM, and Hill coefficients of 0.94 and 1.1, respectively. However, when the cysteine residue in the Walker A motif of the first nucleotide binding fold (NBF1) of SUR1 was replaced with serine (C717S), photoaffinity labeling was not inhibited by 100 microM NEM. These results suggest that NBF1 of SUR1 has a NEM-sensitive structure similar to that of NBF1 of MDR1, a multidrug transporter, and confirm NBF1 as the high-affinity ATP binding site on SUR1.
spellingShingle Matsuo, M
Tucker, S
Ashcroft, F
Amachi, T
Ueda, K
NEM modification prevents high-affinity ATP binding to the first nucleotide binding fold of the sulphonylurea receptor, SUR1.
title NEM modification prevents high-affinity ATP binding to the first nucleotide binding fold of the sulphonylurea receptor, SUR1.
title_full NEM modification prevents high-affinity ATP binding to the first nucleotide binding fold of the sulphonylurea receptor, SUR1.
title_fullStr NEM modification prevents high-affinity ATP binding to the first nucleotide binding fold of the sulphonylurea receptor, SUR1.
title_full_unstemmed NEM modification prevents high-affinity ATP binding to the first nucleotide binding fold of the sulphonylurea receptor, SUR1.
title_short NEM modification prevents high-affinity ATP binding to the first nucleotide binding fold of the sulphonylurea receptor, SUR1.
title_sort nem modification prevents high affinity atp binding to the first nucleotide binding fold of the sulphonylurea receptor sur1
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