ABCC7 p.Glu621Gly
| Predicted by SNAP2: | A: N (61%), C: D (63%), D: N (87%), F: D (75%), G: N (78%), H: D (66%), I: D (75%), K: N (66%), L: D (53%), M: D (71%), N: N (93%), P: D (66%), Q: N (87%), R: D (59%), S: N (66%), T: N (57%), V: N (57%), W: D (80%), Y: D (75%), |
| Predicted by PROVEAN: | A: D, C: D, D: N, F: D, G: D, H: N, I: D, K: N, L: D, M: D, N: N, P: D, Q: N, R: D, S: N, T: D, V: D, W: D, Y: D, |
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[hide] C terminus of nucleotide binding domain 1 contains... J Biol Chem. 2010 Jul 16;285(29):22132-40. Epub 2010 Apr 30. Billet A, Melin P, Jollivet M, Mornon JP, Callebaut I, Becq F
C terminus of nucleotide binding domain 1 contains critical features for cystic fibrosis transmembrane conductance regulator trafficking and activation.
J Biol Chem. 2010 Jul 16;285(29):22132-40. Epub 2010 Apr 30., 2010-07-16 [PMID:20435887]
Abstract [show]
The cystic fibrosis transmembrane conductance regulator (CFTR) is a Cl(-) channel physiologically important in fluid-transporting epithelia and pathologically relevant in several human diseases. Here, we show that mutations in the C terminus of the first nucleotide binding domain comprising the latest beta strands (beta(c)5 and beta(c)6) influence the trafficking, channel activity, and pharmacology of CFTR. We mutated CFTR amino acids located in the beta(c)5-beta(c)6 hairpin, within the beta(c)5 strand (H620Q), within the beta-turn linking the two beta strands (E621G, G622D), as well as within (S623A, S624A) and at the extremity (G628R) of the beta(c)6 strand. Functional analysis reveals that the current density was largely reduced for G622D and G628R channels compared with wt CFTR, similar for E621G and S624A, but increased for H620Q and S623A. For G622D and G628R, the abnormal activity is likely due to a defective maturation process, as assessed by the augmented activity and mature C-band observed in the presence of the trafficking corrector miglustat. In addition, in presence of the CFTR activator benzo[c]quinolizinium, the CFTR current density compared with that of wt CFTR was abolished for G622D and G628R channels, but similar for H620Q, S623A, and S624A or slightly increased for E621G. Finally, G622D and G628R were activated by the CFTR agonists genistein, RP-107, and isobutylmethylxanthine. Our results identify the C terminus of the CFTR first nucleotide binding domain as an important molecular site for the trafficking of CFTR protein, for the control of CFTR channel gating, and for the pharmacological effect of a dual activity agent.
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None has been submitted yet.
No. Sentence Comment
2 We mutated CFTR amino acids located in the betac5-betac6 hairpin, within the betac5 strand (H620Q), within the beta-turn linking the two beta strands (E621G, G622D), as well as within (S623A, S624A) and at the extremity (G628R) of the betac6 strand.
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ABCC7 p.Glu621Gly 20435887:2:151
status: NEW3 Functional analysis reveals that the current density was largely reduced for G622D and G628R channels compared with wt CFTR, similar for E621G and S624A, but increased for H620Q and S623A.
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ABCC7 p.Glu621Gly 20435887:3:137
status: NEW5 In addition, in presence of the CFTR activator benzo[c]quinolizinium, the CFTR current density compared with that of wt CFTR was abolished for G622D and G628R channels, but similar for H620Q, S623A, and S624A or slightly increased for E621G.
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ABCC7 p.Glu621Gly 20435887:5:235
status: NEW33 We have mutated these two glycine residues in aspartic acid (G622D) and arginine (G628R) and considered other mutants in their neighborhood (H620Q, E621G, S623A, and S624A).
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ABCC7 p.Glu621Gly 20435887:33:148
status: NEW87 RESULTS Expression of the NBD1 C-terminal CFTR Mutants-We have introduced EGFP-tagged CFTR proteins into HEK293 cells, wt CFTR and six CFTR mutants, i.e. H620Q, E621G, G622D, S623A, S624A, and G628R.
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ABCC7 p.Glu621Gly 20435887:87:161
status: NEW90 For the expression of CFTR mutants H620Q, E621G, S623A, and S624A, the profiles of core-glycosylated and mature-glycosylated forms were similar to that of the wt protein.
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ABCC7 p.Glu621Gly 20435887:90:42
status: NEW108 First, Cl- currents recorded for wt CFTR, E621G, and S624A CFTR mutants were not significantly different (mean current densities for each construct are reported in supplemental Table 2).
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ABCC7 p.Glu621Gly 20435887:108:42
status: NEW131 On the contrary, a significant increase of I/V slope (Fig. 7A) in presence of MPB-91 was observed for E621G CFTR channels compared with wt (I/V slope of wt, 0.390 Ϯ 0.014, n ϭ 6; E621G, 0.628 Ϯ 0.018, n ϭ 8).
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ABCC7 p.Glu621Gly 20435887:131:102
status: NEWX
ABCC7 p.Glu621Gly 20435887:131:191
status: NEW173 Indeed, our recordings of Cl currents supported by CFTR mutants E621G and S624A were not different from the non-mutated channels stimulated either by Fsk or by MPB agents.
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ABCC7 p.Glu621Gly 20435887:173:64
status: NEW180 In addition, MPB-91 was also able to activate H620Q, E621G, S623A, and S624A mutants.
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ABCC7 p.Glu621Gly 20435887:180:53
status: NEW181 The Cl- current densities elicited by these mutants, except for E621G, were similar to wt.
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ABCC7 p.Glu621Gly 20435887:181:64
status: NEW190 For the CFTR E621G mutant, Cl- current activated by MPB-91 was increased compared with wt.
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ABCC7 p.Glu621Gly 20435887:190:13
status: NEW202 Thus, one might hypothesize that the E621G mutation may reinforce the effect of MPB-91 by acting on critical features of the NBD interface, for example by contributing to reinforce it.
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ABCC7 p.Glu621Gly 20435887:202:37
status: NEW