ABCMdb

PMID: 11242048

Choi JY, Muallem D, Kiselyov K, Lee MG, Thomas PJ, Muallem S
Aberrant CFTR-dependent HCO3- transport in mutations associated with cystic fibrosis.
Nature. 2001 Mar 1;410(6824):94-7., 2001-03-01 [PubMed]

Sentences

No. Mutations Sentence Comment

18 ABCC7 p.Arg117His ABCC7 p.Ile148Thr Two of the mutations, I148T and R117H, are relatively common, and thus the clinical data are solid. Login to comment 23 ABCC7 p.Arg117His ABCC7 p.Arg117His ABCC7 p.Ile148Thr ABCC7 p.Ile148Thr To validate the ability of this procedure to accurately report Cl-channel activity, we determined the correlation between expression ef®ciency (green ¯uorescent protein (GFP) ¯uorescence), Cl- current and changes in [Cl- ]i in cells transfected with CFTR, CFTR(I148T) and CFTR(R117H). Login to comment 24 ABCC7 p.Arg117His ABCC7 p.Arg117His ABCC7 p.Arg117His ABCC7 p.Arg117His ABCC7 p.Arg117His ABCC7 p.Arg117His ABCC7 p.Arg117His ABCC7 p.Arg117His ABCC7 p.Arg117His ABCC7 p.Arg117His ABCC7 p.Arg117His ABCC7 p.Arg117His ABCC7 p.Arg117His ABCC7 p.Arg117His ABCC7 p.Ile148Thr ABCC7 p.Ile148Thr ABCC7 p.Ile148Thr ABCC7 p.Ile148Thr ABCC7 p.Ile148Thr ABCC7 p.Ile148Thr ABCC7 p.Ile148Thr ABCC7 p.Ile148Thr ABCC7 p.Ile148Thr ABCC7 p.Ile148Thr ABCC7 p.Ile148Thr ABCC7 p.Ile148Thr ABCC7 p.Ile148Thr ABCC7 p.Ile148Thr Figure 1a±h shows that similar results are reported by measurement of Cl- current and [Cl- ]i for CFTR and the mutants. Therefore, the Cl-transport capacity of all other CFTR letters to nature 94 NATURE | VOL 410 | 1 MARCH 2001 |www.nature.com NO3 - NO3 - NO3 - Forskolin 5 µM Forskolin 5 µM Forskolin 5 µM Cl-free Forskolin 5 µM Cl-free Cl-free Forskolin 5 µM Forskolin 5 µM 0.25 pHunits 250 s e WT f I148T g R117H i WT j I148T k R117H 10mMCl- 200 s 0 0.2 0.4 [Cl- ]change (mMs-1 ) n=6 n=4 n=3 WT R117H I148T 0 0.2 0.4 0.6 0.8 1.0 HCO3 -transport (∆pH+ min-1 ) n=8 n=4 n=3 I148T R117H WT l a WT b I148T c d h R117H 0 8 16 24 n=5 n=4n=3 WT I148T R117H Current (pApF-1 perGFP fluorescence) 120 s 100pA For 5 µMFor 5 µMFor 5 µM Figure 1 cAMP-stimulated Cl- and HCO3 transport by wild-type (WT) CFTR and the CFTR mutants I148T and R117H. Login to comment 32 ABCC7 p.Arg117His ABCC7 p.Ile148Thr (c) 2001 Macmillan Magazines Ltd mutants was evaluated from changes in [Cl- ]i. Figure 1e±l shows the experimental protocols used to measure the effect of the I148T and R117H mutations on Cl- and HCO3 transport. Login to comment 33 ABCC7 p.Ile148Thr The I148T mutant is normally processed and mediates macroscopicCl- current(Fig.1d;ref.16),single-channelproperties16 and Cl- ¯uxes (Fig. 1h) indistinguishable from those of wild-type CFTR, but is associated with CF with pancreatic insuf®ciency. Login to comment 34 ABCC7 p.Ile148Thr Replacing external Cl- with NO3 in non-stimulated cells caused a slow Clef¯ux in cells expressing CFTR or the I148T mutant. Login to comment 36 ABCC7 p.Gly1244Glu ABCC7 p.Gly1349Asp ABCC7 p.Ser1255Pro ABCC7 p.Ile148Thr ABCC7 p.Ala1067Thr ABCC7 p.Gly178Arg Similar rates were measured for the I148T, G178R, A1067T, G1244E, S1255P and G1349D mutants (see Fig. 3 for location of these mutations in CFTR), all of which are associated with CF with pancreatic insuf®- ciency. Login to comment 44 ABCC7 p.Ile148Thr Results for the I148T mutant are shown in Fig. 1, and the averaged results for all mutants are listed in Table 1 in the Supplementary Information. Login to comment 46 ABCC7 p.Arg117His The results obtained with the R117H mutation are illustrated in Fig. 1. Login to comment 47 ABCC7 p.Arg117His In sharp contrast with the results obtained with the mutants associated with CF with pancreatic insuf®ciency, and in agreement with previous reports25 , the R117H mutation reduced Cl- current and the MQAE response by about 70%. Login to comment 48 ABCC7 p.Arg117His By contrast, the R117H mutation reduced the ability of CFTR to support HCO3 transport by only 37%. Login to comment 49 ABCC7 p.Arg1070Gln ABCC7 p.Glu193Lys ABCC7 p.Asp648Val The E193K, D648V, H949Yand R1070Q mutants, all associated with CF with pancreatic suf®ciency, had no effect on Cl-transport but reduced HCO3 transport by 50±65%. Login to comment 50 ABCC7 p.Gly551Asp ABCC7 p.Gly551Ser ABCC7 p.Ala800Gly ABCC7 p.His620Gln Two sets of particularly interesting mutants are G551D and G551S and H620Q and A800G. Login to comment 51 ABCC7 p.Gly551Ser G551S, which is associated with CF with pancreatic suf®ciency, had no effect on Cl-transport but reduced HCO3 transport by 59% (Fig. 2). Login to comment 52 ABCC7 p.Gly551Asp As reported previously17,18,26 , G551D reduced Cl-transport to 53% of the control value. Login to comment 54 ABCC7 p.Ala800Gly ABCC7 p.His620Gln When expressed in oocytes, the H620Q and A800G mutants increased the macroscopic Cl- current about threefold and the channel open probability by 150±180% (ref. 19). Login to comment 56 ABCC7 p.Ala800Gly Despite these markedly enhanced Cl- ¯uxes, the A800G mutation, which causes CF with pancreatic suf®ciency, only stimulated HCO3 transport to 75% of the wild-type CFTR value. Login to comment 57 ABCC7 p.His620Gln The H620Q mutant, found in one CF patient with pancreatic insuf®ciency, only stimulated HCO3 transport about 13% as effectively as did CFTR. Login to comment 60 ABCC7 p.Arg1070Gln In this respect, the R1070Q mutation, in the few documented cases, has been found to be associated with CF with either pancreatic suf®ciency or pancreatic insuf®ciency. Login to comment 66 ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp ABCC7 p.Gly551Ser ABCC7 p.Gly551Ser ABCC7 p.Gly551Ser ABCC7 p.Gly551Ser ABCC7 p.Gly551Ser ABCC7 p.Gly551Ser ABCC7 p.Gly551Ser ABCC7 p.Ala800Gly ABCC7 p.Ala800Gly ABCC7 p.Ala800Gly ABCC7 p.Ala800Gly ABCC7 p.Ala800Gly ABCC7 p.Ala800Gly ABCC7 p.Ala800Gly ABCC7 p.His620Gln ABCC7 p.His620Gln ABCC7 p.His620Gln ABCC7 p.His620Gln ABCC7 p.His620Gln ABCC7 p.His620Gln Notably, although a few of these mutants exhibit altered letters to nature NATURE |VOL 410 |1 MARCH 2001 |www.nature.com 95 NO3 - Forskolin 5 µM NO3 - Forskolin 5 µM a G551S b G551D 10mMCl- 200 s NO3 - NO3 - Forskolin 5 µM Forskolin 5 µM f H620Q g A800G h H620Q Forskolin 5 µMCl- free Cl- freeCl- free Cl-free c G551S d G551D Forskolin 5 µM Forskolin 5 µM 0.25pHunits 250 s e A800G 0 0.25 0.50 0.75 1.00 H620Q A800G G551D G551S j WT Forskolin 5 µM 0 0.25 0.50 0.75 1.00 H620Q A800G G551D G551S WT i [Cl- ]change(mMs-1 )HCO3 -transport (∆pH+ min-1 ) Figure 2 cAMP-stimulated Cl- and HCO3 transport by CFTR mutants associated with a severe or a mild form of CF. Login to comment 70 ABCC7 p.Arg117His In this regard, although the R117H mutation markedly reduces Cl-channel activity and Cl-transport (Fig. 1), it is associated with a mild form of CF, probably because it supports substantial HCO3 transport (Fig. 1). Login to comment 155 ABCC7 p.Gly551Asp Illek, B. et al. Defective function of the cystic ®brosis-causing missense mutation G551D is recovered by genistein. Login to comment 186 ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp ABCC7 p.Arg117His ABCC7 p.Gly551Ser ABCC7 p.Gly551Ser ABCC7 p.Gly1244Glu ABCC7 p.Gly1244Glu ABCC7 p.Gly1349Asp ABCC7 p.Gly1349Asp ABCC7 p.Ser1255Pro ABCC7 p.Ser1255Pro ABCC7 p.Ile148Thr ABCC7 p.Arg1070Gln ABCC7 p.Arg1070Gln ABCC7 p.Gly970Arg ABCC7 p.Gly970Arg ABCC7 p.His949Tyr ABCC7 p.His949Tyr ABCC7 p.Arg297Gln ABCC7 p.Arg297Gln ABCC7 p.Ala800Gly ABCC7 p.Ala800Gly ABCC7 p.Ala1067Thr ABCC7 p.Ala1067Thr ABCC7 p.Gly178Arg ABCC7 p.Gly178Arg ABCC7 p.Glu193Lys ABCC7 p.Glu193Lys ABCC7 p.Asp648Val ABCC7 p.His620Gln ABCC7 p.His620Gln letters to nature 96 NATURE |VOL 410 |1 MARCH 2001 |www.nature.com HCO3 -/Cl- transportratio 0 0.25 0.50 0.75 1.00 WT I148T G178R R297Q G551D H620Q G970R A1067T G1244E S1255P G1349D E193K G551S A800G H949Y R1070Q Pancreatic insufficient Pancreatic sufficientD648V N CI148T G178R E193K R297Q R117H A1067T R1070Q G1244E S1255P G1349D NBD2 RD H949Y G970R CL4CL3CL2CL1 NBD1 G551D G551S H620Q D648V A800G Figure 3 The HCO3:Cl-transport ratio of CFTR mutants associated with CF. Login to comment 212 ABCC7 p.Gly970Arg Acknowledgements We thank H. Cuppens from the European CF Consortium for informing us that the G970R mutation results in pancreatic insuf®ciency. Login to comment