ABCMdb

PMID: 15561899

Campbell JD, Proks P, Lippiat JD, Sansom MS, Ashcroft FM
Identification of a functionally important negatively charged residue within the second catalytic site of the SUR1 nucleotide-binding domains.
Diabetes. 2004 Dec;53 Suppl 3:S123-7., [PubMed]

Sentences

No. Mutations Sentence Comment

5 ABCC8 p.Asp860Ala We tested this prediction experimentally and found that, unlike wild-type channels, channels containing the SUR1-D860A mutation were not activated by MgADP in either the presence or absence of MgATP. Login to comment 72 ABCC8 p.Glu1506Lys C: Expanded view of site 2 of the SUR1 model showing the proximity of D860 to the ATP ␥-phosphate in Site 2. because its mutation to lysine (E1506K) leads to congenital hyperinsulinism in humans (18). Login to comment 77 ABCC8 p.Asp860Ala Effects of the D860A mutation on Mg nucleotide activation. Login to comment 82 ABCC8 p.Asp860Ala Addition of 100 ␮mol/l MgATP produced a greater block of Kir6.2/SUR1-D860A channels than of wild-type channels: 95 Ϯ 1% (n ϭ 3) compared with 85 Ϯ 5% (n ϭ 3) (Fig. 2). Login to comment 84 ABCC8 p.Asp860Ala MgADP was unable to stimulate the activity of channels carrying the D860A mutation in the presence of ATP, in contrast to wild-type channels (Fig. 2). Login to comment 85 ABCC8 p.Asp1512Ala The equivalent mutation in NBD2 of SUR1 (D1512A) did not result in functional channels. Login to comment 88 ABCC8 p.Asp860Ala A: Macroscopic currents recorded from oocytes coexpressing Kir6.2 and either SUR1, or SUR2B- D860A in response to a series of voltage ramps from -110 to ؉100 mV. 100 ␮mol/l ADP and 100 ␮mol/l ATP were added to the intracellular solution as indicated by the bars. Login to comment 90 ABCC8 p.Asp860Ala B: Mean KATP conductance recorded in response to 100 ␮mol/l ADP, 100 ␮mol/l ATP, or 100 ␮mol/l ADP ؉ 100 ␮mol/l ATP in patches excised from oocytes coexpressing Kir6.2 and either wild-type SUR1 (Ⅺ) or SUR1-D860A (f). Login to comment 104 ABCC8 p.Asp860Ala We ran four simulations: the wild-type model with 1) ATP docked at both NBDs, or 2) ATP docked at NBD1 and ADP docked at NBD2, and 3, 4) the equivalent simulations of the D860A mutant. Login to comment 106 ABCC8 p.Asp860Ala Furthermore, the D860A simulations demonstrate that removal of the negatively charged aspartate disrupts the interaction of R1379 with nucleotide; in contrast to the wild-type simulations, R1379 more strongly interacts with the ATP than with ADP. Login to comment