ABCMdb

ABCC7 p.Asn1148Ala

ClinVar:	c.3444C>A , p.Asn1148Lys ? , not provided c.3443A>G , p.Asn1148Ser ? , not provided
CF databases:	c.3443A>G , p.Asn1148Ser (CFTR1) ? , c.3444C>A , p.Asn1148Lys (CFTR1) ? , This mutation was found by DGGE and direct DNA sequencing in a child with bronchiectasis and sweat test borderline.
Predicted by SNAP2:	A: D (66%), C: D (66%), D: D (80%), E: D (80%), F: D (75%), G: D (75%), H: D (80%), I: D (66%), K: D (63%), L: D (71%), M: D (71%), P: D (85%), Q: D (63%), R: D (66%), S: D (63%), T: D (66%), V: D (63%), W: D (91%), Y: D (80%),
Predicted by PROVEAN:	A: N, C: D, D: N, E: N, F: D, G: N, H: N, I: N, K: N, L: N, M: N, P: N, Q: N, R: N, S: N, T: N, V: N, W: D, Y: N,

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Publications
[hide] Differential contribution of TM6 and TM12 to the p... Pflugers Arch. 2012 Mar;463(3):405-18. Epub 2011 Dec 13. Cui G, Song B, Turki HW, McCarty NA
Differential contribution of TM6 and TM12 to the pore of CFTR identified by three sulfonylurea-based blockers.
Pflugers Arch. 2012 Mar;463(3):405-18. Epub 2011 Dec 13., [PMID:22160394]

Abstract [show]
Previous studies suggested that four transmembrane domains 5, 6, 11, 12 make the greatest contribution to forming the pore of the CFTR chloride channel. We used excised, inside-out patches from oocytes expressing CFTR with alanine-scanning mutagenesis in amino acids in TM6 and TM12 to probe CFTR pore structure with four blockers: glibenclamide (Glyb), glipizide (Glip), tolbutamide (Tolb), and Meglitinide. Glyb and Glip blocked wildtype (WT)-CFTR in a voltage-, time-, and concentration-dependent manner. At V (M) = -120 mV with symmetrical 150 mM Cl(-) solution, fractional block of WT-CFTR by 50 muM Glyb and 200 muM Glip was 0.64 +/- 0.03 (n = 7) and 0.48 +/- 0.02 (n = 7), respectively. The major effects on block by Glyb and Glip were found with mutations at F337, S341, I344, M348, and V350 of TM6. Under similar conditions, fractional block of WT-CFTR by 300 muM Tolb was 0.40 +/- 0.04. Unlike Glyb, Glip, and Meglitinide, block by Tolb lacked time-dependence (n = 7). We then tested the effects of alanine mutations in TM12 on block by Glyb and Glip; the major effects were found at N1138, T1142, V1147, N1148, S1149, S1150, I1151, and D1152. From these experiments, we infer that amino acids F337, S341, I344, M348, and V350 of TM6 face the pore when the channel is in the open state, while the amino acids of TM12 make less important contributions to pore function. These data also suggest that the region between F337 and S341 forms the narrow part of the CFTR pore.

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Sentences [show]
No. Sentence Comment
150 Surprisingly, nine mutations of TM12, including N1138A, M1140A, T1142A, V1147A, N1148A, S1149A, S1150A, I1151A, and D1152A, exhibited significantly altered block by Glyb; the pattern was not consistent with either α-helix or β-strand secondary structure along the full length of the region studied. Login to comment
163 Effects on time-dependent block by mutations R334A and K335A Fractional block by Glip200 μM V1153A D1152A I1151A S1150A S1149A N1148A V1147A A1146S W1145A Q1144A L1143A T1142A S1141A M1140A I1139A N1138A M1137A A1136S L1135A T1134A WT 0 0.2 0.4 0.6 0.8 * ** ** ** ** ** ** * V1153A D1152A I1151A S1150A S1149A N1148A V1147A A1146S W1145A Q1144A L1143A T1142A S1141A M1140A I1139A N1138A M1137A A1136S L1135A T1134A WT 0 0.2 0.4 0.6 0.8 1.0 * * * * * ** ** ** ** Fractional block by Glyb50 μM Fig. 4 Alanine-scanning in TM12 to identify amino acids that interact with Glyb and Glip. Login to comment
180 Surprisingly, several mutations in TM12 Q1144A, V1147A, N1148A, S1149A, S1150A, and I1151A affected the voltage-dependence of block by Glyb (Fig. 8b). Login to comment