ABCMdb

ABCC7 p.Arg553Lys

ClinVar:	c.1657C>T , p.Arg553* D , Pathogenic c.1657C>G , p.Arg553Gly ? , not provided c.1658G>A , p.Arg553Gln D , Pathogenic
CF databases:	c.1657C>T , p.Arg553* D , CF-causing c.1657C>G , p.Arg553Gly (CFTR1) ? , This mutation was found identified by DGGE and direct sequencing. This nucleotide change was observe in a French CF chromosome. c.1658G>A , p.Arg553Gln (CFTR1) ? , The amino acid change was found in a German CF patient on the maternal [delta]F508 CF chromosome associated with the haplotype 1-2-1-1-1-2 in J3.11(Msp) - KM.19 (Pst) - XV-2c - metH(Msp) - metH (Taq) - metD(taq). The paternal CF chromosome carries the 553X Stop mutation. So far, the R553Q mutation was not found on a small number of normal and of CF [delta]F508 or non-[delta]F508 chromosomes. Since this mutation occurs in the region of sequence identity with other membrane-associated proteins or transport systems that may contain glutamine instead of a basic amino acid at this position, we assume that this mutation may be neither a polymorphism nor may cayse disease but rather modulates the function of the [delta]F508 CFTR gene product.
Predicted by SNAP2:	A: D (95%), C: D (95%), D: D (95%), E: D (95%), F: D (95%), G: D (95%), H: D (95%), I: D (95%), K: D (85%), L: D (95%), M: D (95%), N: D (95%), P: D (95%), Q: D (59%), S: D (95%), T: D (95%), V: D (95%), W: D (95%), Y: D (95%),
Predicted by PROVEAN:	A: D, C: D, D: D, E: N, F: D, G: D, H: D, I: D, K: N, L: D, M: D, N: D, P: D, Q: N, S: D, T: D, V: D, W: D, Y: D,

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Publications
[hide] Cystic fibrosis in Uruguay. Genet Mol Res. 2002 Mar 31;1(1):32-8. Luzardo G, Aznarez I, Crispino B, Mimbacas A, Martinez L, Poggio R, Zielenski J, Tsui LC, Cardoso H
Cystic fibrosis in Uruguay.
Genet Mol Res. 2002 Mar 31;1(1):32-8., [PMID:14963811]

Abstract [show]
We conducted clinical and genetic analyses of 52 cystic fibrosis (CF) patients in Uruguay, which is about half of the known affected individuals in the country. A relatively high proportion had a mild presentation, characterized by pancreatic sufficiency (28%), a strong pulmonary component (97%), and borderline sweat electrolyte measurements (25%). Mutational analysis of CF chromosomes demonstrated a relatively low incidence of the DeltaF508 allele (40%) and a large number of other cystic fibrosis conductance regulator mutations, with an overall detection rate of about 71%. Fifteen different mutations were detected in our patients: DeltaF508, G542X, R1162X, G85E, N1303K, R334W, R75Q, R74W, D1270N, W1282X, DeltaI507, 2789+5G-->A, R1066C, -816C/T, R553X, as well as RNA splicing variant IVS8-5T. This group of Uruguayan CF patients has some characteristics in common with other populations of similar origin (Hispanics), as well as some unique characteristics.

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No. Sentence Comment
59 Genotypes N Percent ∆F508/∆F508 ∆F508/R1162X ∆F508/G85E ∆F508/G542X ∆F508/5T ∆F508/R334W ∆F508/1303X ∆F508/R1066C ∆F508/Unknown ∆I507/2789+G-A R74W/D1270N N1303K/G542X N1303K/R553K -816C-T/5T 5T/Unknown G542X/Unknown R75Q/Unknown W1282X/Unknown Unknown/Unknown 8 3 3 3 2 2 1 1 11 1 1 1 1 1 2 2 2 1 6 15.4 5.8 5.8 5.8 3.9 3.9 1.9 1.9 21.2 1.9 1.9 1.9 1.9 1.9 3.9 3.9 3.9 1.9 11.5 All individuals had pulmonary symptoms.All those carrying the ∆F508/∆F508 genotype had pancreatic insufficiency. Login to comment

[hide] Human-mouse cystic fibrosis transmembrane conducta... Proc Natl Acad Sci U S A. 2012 Jan 17;109(3):917-22. Epub 2011 Dec 30. Dong Q, Ostedgaard LS, Rogers C, Vermeer DW, Zhang Y, Welsh MJ
Human-mouse cystic fibrosis transmembrane conductance regulator (CFTR) chimeras identify regions that partially rescue CFTR-DeltaF508 processing and alter its gating defect.
Proc Natl Acad Sci U S A. 2012 Jan 17;109(3):917-22. Epub 2011 Dec 30., [PMID:22210114]

Abstract [show]
The DeltaF508 mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene is the most common cause of cystic fibrosis. The mutation disrupts biosynthetic processing, reduces channel opening rate, and decreases protein lifetime. In contrast to human CFTR (hCFTR)-DeltaF508, mouse CFTR-DeltaF508 is partially processed to the cell surface, although it exhibits a functional defect similar to hCFTR-DeltaF508. To explore DeltaF508 abnormalities, we generated human-mouse chimeric channels. Substituting mouse nucleotide-binding domain-1 (mNBD1) into hCFTR partially rescued the DeltaF508-induced maturation defect, and substituting mouse membrane-spanning domain-2 or its intracellular loops (ICLs) into hCFTR prevented further DeltaF508-induced gating defects. The protective effect of the mouse ICLs was reverted by inserting mouse NBDs. Our results indicate that the DeltaF508 mutation affects maturation and gating via distinct regions of the protein; maturation of CFTR-DeltaF508 depends on NBD1, and the DeltaF508-induced gating defect depends on the interaction between the membrane-spanning domain-2 ICLs and the NBDs. These appear to be distinct processes, because none of the chimeras repaired both defects. This distinction was exemplified by the I539T mutation, which improved CFTR-DeltaF508 processing but worsened the gating defect. Our results, together with previous studies, suggest that many different NBD1 modifications improve CFTR-DeltaF508 maturation and that the effect of modifications can be additive. Thus, it might be possible to enhance processing by targeting several different regions of the domain or by targeting a network of CFTR-associated proteins. Because no one modification corrected both maturation and gating, perhaps more than a single agent will be required to correct all CFTR-DeltaF508 defects.

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No. Sentence Comment
169 In addition, a variant that combined G550E with R553M and R553K increased processing and current, although the effect on channel kinetics was not tested (33). Login to comment

[hide] Enhancing the Potency of F508del Correction: A Mul... J Pharmacol Clin Toxicol. 2013 Aug 28;1(1):1007. Kirby EF, Heard AS, Wang XR
Enhancing the Potency of F508del Correction: A Multi-Layer Combinational Approach to Drug Discovery for Cystic Fibrosis.
J Pharmacol Clin Toxicol. 2013 Aug 28;1(1):1007., [PMID:24855632]

Abstract [show]
With better understanding of the cellular and molecular pathophysiology underlying cystic fibrosis (CF), novel drugs are being developed that specifically target the molecular defects of the cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-activated chloride channel on the plasma membrane that causes CF. Starting with cell-based high-throughput screening, small molecules have been identified that are able to fix specific molecular defects of various disease-causing CFTR mutants. With the successful development of ivacaftor, a "potentiator" that enhances CFTR chloride channel activity, new types of small-molecule compounds that "correct" the misfolding and misprocessing of the most common CF-causing mutation, F508del, are actively being sought for. Recent studies focused on the potential mechanisms of action of some of the investigational CFTR "correctors" shed new light on how the F508del mutant can be targeted in an attempt to ameliorate the clinical symptoms associated with CF. A multi-layer combinational approach has been proposed to achieve the high-potency correction necessary for significant clinical outcome. The mechanistic insights obtained from such studies will shape the future therapeutics development for the vast majority of CF patients.

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No. Sentence Comment
67 In contrast, combined second-site suppressor mutations R553K/R555K (2RK) in NBD1 not only alter the protease susceptibility of NBD1 but also that of other domains of F508del CFTR. Login to comment