ABCMdb

PMID: 12169627

Matsuo M, Dabrowski M, Ueda K, Ashcroft FM
Mutations in the linker domain of NBD2 of SUR inhibit transduction but not nucleotide binding.
EMBO J. 2002 Aug 15;21(16):4250-8., [PubMed]

Sentences

No. Mutations Sentence Comment

30 ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp ABCC7 p.Ser549Arg Likewise, the CFTR linker mutations G551D and S549R did not change the ATP-binding af®nity of puri®ed NBD1 (Qu et al., 1997), whereas G551D reduced the ATPase activity (Li et al., 1996). Login to comment 100 ABCC8 p.His888Ala ABCC8 p.Gln774Ala Mutation of Q774A or H888A in NBD1 of SUR1 did not result in functional channels. Login to comment 101 ABCC8 p.Gln1426Ala ABCC8 p.His1537Ala In contrast, the equivalent mutations in NBD2 (Q1426A and H1537A) did not affect functional expression. Login to comment 104 ABCC8 p.Gln1426Ala ABCC8 p.Gln1426Ala ABCC8 p.His1537Ala ABCC8 p.His1537Ala However, both the Q1426A and H1537A mutations reduced the ability of 100 mM MgADP to stimulate channel activity, resulting in a 50 T 5.2% (n = 5) block of Kir6.2/SUR1-Q1426A currents and a 30 T 2.6% (n = 11) block of Kir6.2/SUR1-H1537A currents (Figure 5). Login to comment 122 ABCC8 p.Gln1426Ala ABCC8 p.His1537Ala Mean KATP conductance recorded from patches excised from oocytes co-expressing Kir6.2 and either wild-type SUR1 or SUR containing mutations in the linker of NBD2 (SUR1-Q1426A and SUR1-H1537A). Login to comment 149 ABCC8 p.Ser830Arg ABCC8 p.Ser830Arg ABCC8 p.Ser1482Arg ABCC8 p.Ser1482Arg Table I. Percentage of photoaf®nity labelling by 8-azido-[a-32P]ATP remaining after displacement with unlabelled ATP or ADP NBD1 (%) NBD2 (%) ATP ADP ATP ADP SUR1 12 T 10 21 T 14 52 T 11 45 T 11 SUR1-S830R 8 T 3.7 25 T 9.0 43 T 11 33 T 6.8 SUR1-S1482R 9 T 5.1 21 T 11 39 T 14 34 T 8.4 Values are expressed as a percentage of 8-azido-[a-32P]ATP bound in the absence of unlabelled ATP (100 mM) or ADP (100 mM). Login to comment 171 ABCC8 p.Gly1484Arg ABCC8 p.Gly1484Asp ABCC8 p.Gln1485His Other mutations (G1484D, G1484R and Q1485H) within the NBD2 linker of SUR1 have also been reported to prevent MgADP activation of the KATP channel (Shyng et al., 1997). Login to comment 204 ABCC8 p.Ser1446Arg ABCC8 p.Ser1446Arg For example, it might in¯uence the local structure of NBD2 such that it is able to tolerate the effect of the serine to arginine mutation at residue 1446. Login to comment 238 ABCC8 p.Ser830Arg ABCC7 p.Ser809Arg ABCC8 p.His888Ala ABCC8 p.Gln774Ala We made the following mutations in the NBD1 linker: SUR1-S830R and SUR2-S809R (S1R); SUR1-Q774A, SUR1-H888A. Login to comment 239 ABCC8 p.Ser1446Arg ABCC8 p.Ser1482Arg ABCC8 p.Gln1426Ala ABCC8 p.His1537Ala Mutations in the NBD2 linker were: SUR1-S1482R and SUR2-S1446R (S2R); SUR1-Q1426A, SUR1-H1537A. Login to comment 260 ABCC8 p.Ser830Arg ABCC8 p.Ser1482Arg Crude membranes, containing similar amounts of wild-type SUR1, SUR1-S830R and SUR1-S1482R, as determined by western blotting, were incubated with 50 mM 8-azido- [a-32P]ATP or 50 mM 8-azido-[g-32P]ATP (ICN Biomedicals) in the presence or absence of 100 mM ATP or 100 mM ADP in 3 ml of TEM buffer (40 mM Tris±HCl pH 7.5, 0.1 mM EGTA and 1 mM MgSO4) containing 2 mM ouabain. Login to comment