ABCMdb

PMID: 9287292

Ueda K, Inagaki N, Seino S
MgADP antagonism to Mg2+-independent ATP binding of the sulfonylurea receptor SUR1.
J Biol Chem. 1997 Sep 12;272(37):22983-6., [PubMed]

Sentences

No. Mutations Sentence Comment

61 ABCC8 p.Asp854Asn ABCC8 p.Lys719Arg ABCC8 p.Lys719Met Substitutions of the conserved lysine in Walker A, K719R and K719M (lanes 2 and 3), or the aspartate in Walker B, D854N (lane 4), abolished the binding of 5 ␮M 8-azido-[␣-32 P]ATP, although substitutions at equivalent sites in NBF2, K1385R, K1385M, or D1506N (lanes 5, 6, and 7) did not affect it. SUR1 with mutations in NBF1 binds ATP only slightly even when incubated with 40 ␮M 8-azido-[␣-32 P]ATP. Login to comment 95 ABCC8 p.Lys719Ala Gribble et al. (28) reported recently that both NBFs in SUR1 are not essential for KATP channel inhibition by ATP, but that they are essential for channel activation by MgADP, using K719A and K1385M SUR1 mutants. Login to comment 96 ABCC8 p.Lys719Arg ABCC8 p.Lys719Met However, we have observed that while K719M and K719R mutants severely impair functional expression of KATP channels, K1385M and K1385R mutants do not.2 Although whether or not SUR1 has ATP hydrolysis activity is unknown, ATP binding to NBF1 of SUR1 might be important in maintaining KATP channels in the operative state. Login to comment 103 ABCC8 p.Asp854Asn ABCC8 p.Lys719Arg ABCC8 p.Lys719Met Lane 1, wild-type SUR1; lane 2, K719R; lane 3, K719M; lane 4, D854N; lane 5, K1385R; lane 6, K1385M; lane 7, D1506N. Login to comment