PMID: 9922375

Sheppard DN, Welsh MJ
Structure and function of the CFTR chloride channel.
Physiol Rev. 1999 Jan;79(1 Suppl):S23-45., [PubMed]
Sentences
No. Mutations Sentence Comment
98 ABCC7 p.Arg347Cys
X
ABCC7 p.Arg347Cys 9922375:98:228
status: NEW
view ABCC7 p.Arg347Cys details
ABCC7 p.Arg334Gln
X
ABCC7 p.Arg334Gln 9922375:98:216
status: NEW
view ABCC7 p.Arg334Gln details
These residues are conserved across spe- because I0 blocks the pore, it appears that I0 is less per- cies, and two are the site of mutations associated with meable under some conditions, including the whole cell CF: R334Q/W and R347C/H/L/P (142). Login to comment
102 ABCC7 p.Lys335Glu
X
ABCC7 p.Lys335Glu 9922375:102:55
status: NEW
view ABCC7 p.Lys335Glu details
ABCC7 p.Lys95Asp
X
ABCC7 p.Lys95Asp 9922375:102:46
status: NEW
view ABCC7 p.Lys95Asp details
This would suggest that like acidic residues (K95D and K335E) altered the whole cell other Cl0 channels, including ligand-gated Cl0 channels in anion permeability sequence by converting CFTR from a neurons (20) and outwardly rectifying Cl0 channels in low I0 permeability pore (Br0 ' Cl0 ú I0 ) to a high I0 epithelia (55), the CFTR pore has a ''weak field strength`` permeability pore (I0 ú Br0 ú Cl0 ) (4). Login to comment
104 ABCC7 p.Arg347Glu
X
ABCC7 p.Arg347Glu 9922375:104:43
status: NEW
view ABCC7 p.Arg347Glu details
ABCC7 p.Arg1030Glu
X
ABCC7 p.Arg1030Glu 9922375:104:53
status: NEW
view ABCC7 p.Arg1030Glu details
Thus, depending on the experimental tants, R347E and R1030E, did not alter the anion perme- conditions and whether block of the channel by I0 is con- ability sequence, although PI/PCl values were increased. Login to comment
112 ABCC7 p.Lys335Cys
X
ABCC7 p.Lys335Cys 9922375:112:20
status: NEW
view ABCC7 p.Lys335Cys details
ABCC7 p.Lys95Cys
X
ABCC7 p.Lys95Cys 9922375:112:11
status: NEW
view ABCC7 p.Lys95Cys details
On mutants K95C and K335C interact with methanethiosulfo- the basis of these data, the minimum diameter of the nate (MTS) reagents, and mutations that eliminate the CFTR pore was estimated to be Ç5.3 A˚ (77), similar to positive charge at K335 reduce single-channel conduc- that reported for other Cl0 channels (10, 20, 55). Login to comment
114 ABCC7 p.Lys335Glu
X
ABCC7 p.Lys335Glu 9922375:114:22
status: NEW
view ABCC7 p.Lys335Glu details
However, the mutation K335E did is controversial (51, 59, 72, 93, 99, 100, 111, 129). Login to comment
118 ABCC7 p.Arg334Trp
X
ABCC7 p.Arg334Trp 9922375:118:182
status: NEW
view ABCC7 p.Arg334Trp details
ABCC7 p.Arg347Pro
X
ABCC7 p.Arg347Pro 9922375:118:192
status: NEW
view ABCC7 p.Arg347Pro details
When expressed in heterologous epithelial cells, the CF-associatedpermeation is determined by the hydration energy of P27-8/ 9j0e$$ja08 01-13-99 14:54:54 prsa APS-Phys Rev mutants R334W and R347P were correctly processed and proteins play an important structural role by kinking a-helices (22). Login to comment
121 ABCC7 p.Arg334Trp
X
ABCC7 p.Arg334Trp 9922375:121:45
status: NEW
view ABCC7 p.Arg334Trp details
ABCC7 p.Arg347Pro
X
ABCC7 p.Arg347Pro 9922375:121:55
status: NEW
view ABCC7 p.Arg347Pro details
Analysis of the single-channel properties of R334W and R347P demonstrated that both mutants decrease sin- or indirectly to the formation of the CFTR pore (119). Login to comment
124 ABCC7 p.Pro99Leu
X
ABCC7 p.Pro99Leu 9922375:124:120
status: NEW
view ABCC7 p.Pro99Leu details
ABCC7 p.Pro99Ala
X
ABCC7 p.Pro99Ala 9922375:124:127
status: NEW
view ABCC7 p.Pro99Ala details
ABCC7 p.Pro99Gly
X
ABCC7 p.Pro99Gly 9922375:124:108
status: NEW
view ABCC7 p.Pro99Gly details
When the basic arginine at this position was re- gle-channel Cl0 conductance in the rank order: wild type ' P99G ú P99L ' P99A (119). Login to comment
128 ABCC7 p.Arg347His
X
ABCC7 p.Arg347His 9922375:128:93
status: NEW
view ABCC7 p.Arg347His details
ABCC7 p.Pro99Cys
X
ABCC7 p.Pro99Cys 9922375:128:17
status: NEW
view ABCC7 p.Pro99Cys details
However, because P99C did(128) could control the pore properties of the CF-associated mutant R347H simply by manipulating pH. Login to comment
129 ABCC7 p.Arg347His
X
ABCC7 p.Arg347His 9922375:129:132
status: NEW
view ABCC7 p.Arg347His details
At pH 5.5, not react with MTS reagents (1), P99 probably does not directly line the CFTR pore.when histidine is positively charged, R347H had normal pore properties (128). Login to comment
130 ABCC7 p.Arg347Pro
X
ABCC7 p.Arg347Pro 9922375:130:225
status: NEW
view ABCC7 p.Arg347Pro details
However, at pH 8.7, when histidine Knowledge of the structure and function of the CFTR pore has also emerged from studies using truncated andis uncharged, single-channel conductance was reduced to a similar extent as that of R347P, and the anomalous mole chimeric proteins (95, 116, 134). Login to comment
131 ABCC7 p.Asp836*
X
ABCC7 p.Asp836* 9922375:131:36
status: NEW
view ABCC7 p.Asp836* details
The amino-terminal portion of CFTR (D836X, which contains MSD1, NBD1 andfraction behavior of CFTR was lost (128). Login to comment
136 ABCC7 p.Asp836*
X
ABCC7 p.Asp836* 9922375:136:61
status: NEW
view ABCC7 p.Asp836* details
Based on biochemical and functional data, we speculated that D836X generates a Cl0 channel byveats noted above regarding the contribution of residues to the pore versus less specific alterations of structure forming a homomultimer (116). Login to comment
138 ABCC7 p.Asp836*
X
ABCC7 p.Asp836* 9922375:138:72
status: NEW
view ABCC7 p.Asp836* details
To identify residues that line the CFTR pore and make below), then in a D836X multimer MSD1 sequences may substitute for MSD2 sequences to form the pore. Login to comment
145 ABCC7 p.Arg352Cys
X
ABCC7 p.Arg352Cys 9922375:145:286
status: NEW
view ABCC7 p.Arg352Cys details
The voltage dependence of the reaction rates of MTS reagents with CFTR (Br0 Å Cl0 ú I0 ), Xenopus CFTR (Br0 Å I0 ú Cl0 ), and human-Xenopus CFTR chimeras in which eithercysteine mutations at these residues and single-channel studies of wild-type CFTR and the mutant R352C suggest MSD1 or MSD2 of human CFTR was replaced with the equivalent region of Xenopus CFTR (hX1-6, Br0 Å I0 úthat the selectivity of CFTR for anions over cations is determined by a site located at the intracellular end of the pore Cl0 , and hX7-12, Br0 ú Cl0 ú I0 , respectively) also suggest that sequences in MSD1 likely determine the anionthat involves the residue R352 (32, 52). Login to comment
148 ABCC7 p.Arg352Cys
X
ABCC7 p.Arg352Cys 9922375:148:75
status: NEW
view ABCC7 p.Arg352Cys details
ABCC7 p.Gln353Cys
X
ABCC7 p.Gln353Cys 9922375:148:157
status: NEW
view ABCC7 p.Gln353Cys details
ABCC7 p.Thr351Cys
X
ABCC7 p.Thr351Cys 9922375:148:148
status: NEW
view ABCC7 p.Thr351Cys details
Therefore, other sequences must account for the differ-end of the pore and R352C is located closer to the extracellular end of the pore than either T351C or Q353C (32). Login to comment
156 ABCC7 p.Arg117Cys
X
ABCC7 p.Arg117Cys 9922375:156:114
status: NEW
view ABCC7 p.Arg117Cys details
First, incorporation of glycosylation sequences into ICL1, ICL3, and ICL4 disrupted protein associated mutations (R117C/H/L/P) (142). Login to comment
157 ABCC7 p.Arg117His
X
ABCC7 p.Arg117His 9922375:157:49
status: NEW
view ABCC7 p.Arg117His details
When expressed in heterologous epithelial cells, R117H was cor-folding, and there was little Cl0 channel function measured (27). Login to comment
159 ABCC7 p.Arg117His
X
ABCC7 p.Arg117His 9922375:159:13
status: NEW
view ABCC7 p.Arg117His details
In addition, R117H had an altered sensitivity to external pH, suggesting thatof human CFTR (36, 149). Login to comment
161 ABCC7 p.Arg117His
X
ABCC7 p.Arg117His 9922375:161:0
status: NEW
view ABCC7 p.Arg117His details
R117H caused a small decrease in single-channel conductance but a dramatic change informs a cAMP-stimulated Cl0 current (46, 58, 61). Login to comment
168 ABCC7 p.Ser945Leu
X
ABCC7 p.Ser945Leu 9922375:168:49
status: NEW
view ABCC7 p.Ser945Leu details
ABCC7 p.Gly970Arg
X
ABCC7 p.Gly970Arg 9922375:168:59
status: NEW
view ABCC7 p.Gly970Arg details
Although, Xenopus CFTR hadships of the mutations S945L and G970R in ICL3 showed weak outward rectification in contrast to that of wild-type a pattern of gating similar to human CFTR, the human-Xenopus CFTR chimera hX1-6 showed a pattern of gatingCFTR (114, 148). Login to comment
169 ABCC7 p.Arg117His
X
ABCC7 p.Arg117His 9922375:169:160
status: NEW
view ABCC7 p.Arg117His details
These results suggest that ICL2 and ICL3 may be located close to the intracellular mouth of the CFTR characterized by a shortened open time, similar to that of R117H (95). Login to comment
176 ABCC7 p.Ile148Thr
X
ABCC7 p.Ile148Thr 9922375:176:27
status: NEW
view ABCC7 p.Ile148Thr details
ABCC7 p.Gly178Arg
X
ABCC7 p.Gly178Arg 9922375:176:37
status: NEW
view ABCC7 p.Gly178Arg details
Furthermore, the mutations I148T and G178R could not be locked open by the nonhydrolyzable ATP analog 5؅- adenylylimidodiphosphate (AMP-PNP) (112), the mutation Information about the CFTR pore has also emerged from studies using Cl0 channel inhibitors. Login to comment
177 ABCC7 p.Arg1066Leu
X
ABCC7 p.Arg1066Leu 9922375:177:223
status: NEW
view ABCC7 p.Arg1066Leu details
ABCC7 p.Phe1052Val
X
ABCC7 p.Phe1052Val 9922375:177:234
status: NEW
view ABCC7 p.Phe1052Val details
Because DPCA1067T altered the relationship between open probability (Po) and ATP concentration (33), and the response of inhibition of CFTR was voltage dependent and enhanced when the external Cl0 concentration was reduced,R1066L and F1052V to pyrophosphate (PPi) was less than wild type (33). Login to comment
183 ABCC7 p.Thr1134Phe
X
ABCC7 p.Thr1134Phe 9922375:183:83
status: NEW
view ABCC7 p.Thr1134Phe details
site could be transferred from S341 to S1141 in M12 while another mutation in M12, T1134F, increased the affinityStudies of CFTR variants lacking the consensus glycosylation sequences in extracellular loop (ECL) 4 of DPC block (87). Login to comment
193 ABCC7 p.Arg347Asp
X
ABCC7 p.Arg347Asp 9922375:193:21
status: NEW
view ABCC7 p.Arg347Asp details
Moreover, the mutant R347D significantly weak- main have had little discernible effect on conduction and permeation, although they have frequently had profoundened the binding of DNDS and DIDS to CFTR, suggesting that R347 contributes to the binding site for disulfonic effects on gating behavior (see below). Login to comment
232 ABCC7 p.Arg347Asp
X
ABCC7 p.Arg347Asp 9922375:232:19
status: NEW
view ABCC7 p.Arg347Asp details
Because the mutant R347D significantly weakened the activity of CFTR Cl0 channels by using excised inside-out membrane patches from cells expressing recombinantbinding of DNDS and DIDS to CFTR, R347 likely contributes to this site (74). Login to comment
248 ABCC7 p.Thr338Cys
X
ABCC7 p.Thr338Cys 9922375:248:31
status: NEW
view ABCC7 p.Thr338Cys details
ABCC7 p.Thr339Cys
X
ABCC7 p.Thr339Cys 9922375:248:41
status: NEW
view ABCC7 p.Thr339Cys details
However, because the mutations T338C and T339C did not react with MTS reagents, the side PKA phosphorylation but did not substitute for ATP in opening phosphorylated CFTR Cl0 channels.chains of these residues do not interact with permeating ions (31, 77). Login to comment
375 ABCC7 p.Lys464Ala
X
ABCC7 p.Lys464Ala 9922375:375:123
status: NEW
view ABCC7 p.Lys464Ala details
ABCC7 p.Gln552Ala
X
ABCC7 p.Gln552Ala 9922375:375:133
status: NEW
view ABCC7 p.Gln552Ala details
This is consistent with the finding that in the absence predicted to decrease the rate of hydrolysis at NBD1, for example, K464A and Q552A, would thus increase the in-of ATP, the channel does not open. Login to comment
382 ABCC7 p.His1350Gln
X
ABCC7 p.His1350Gln 9922375:382:38
status: NEW
view ABCC7 p.His1350Gln details
In addition, the observation that the H1350Q mutation, which would be predicted to increase the ratechannel. Login to comment
497 ABCC7 p.Ser753Ala
X
ABCC7 p.Ser753Ala 9922375:497:18
status: NEW
view ABCC7 p.Ser753Ala details
The mutation 10SA-S753A eliminates much Additional evidence for phosphorylation-dependent control of CFTR channel activity comes from observa-of the residual PKA-dependent phosphorylation of the 10SA mutant and decreases the Po of the 10SA mutant by tions that there appear to be both high and low phosphorylation states correlating with a high and low Po (43, 64).40% (115). Login to comment
504 ABCC7 p.Asp836*
X
ABCC7 p.Asp836* 9922375:504:70
status: NEW
view ABCC7 p.Asp836* details
First, those sites were phosphor- interference between R domains in a D836X homomultimer.ylated in vivo after stimulation with cAMP agonists. Login to comment
521 ABCC7 p.Ser660Ala
X
ABCC7 p.Ser660Ala 9922375:521:156
status: NEW
view ABCC7 p.Ser660Ala details
When S660 in CFTRDR was mutated to alanine dan (42) proposed a two-domain model of the R domain: RD1 (amino acids 587-672) and RD2 (amino acids 679-(CFTRDR-S660A), PKA failed to stimulate channel activity. Login to comment
526 ABCC7 p.Ser660Ala
X
ABCC7 p.Ser660Ala 9922375:526:111
status: NEW
view ABCC7 p.Ser660Ala details
ABCC7 p.Asp836*
X
ABCC7 p.Asp836* 9922375:526:318
status: NEW
view ABCC7 p.Asp836* details
In addition, deletion studies of portions of the R domain suggest thatout that PKA cannot interact with CFTRDR-S660A, even though it does interact with CFTRDR. there are two halves to the R domain with the first conserved in other ABC transporters and the second uniqueLike CFTRDR, the amino-terminal portion of CFTR (D836X, which contains MSD1, NBD1, and the R domain) to CFTR (102, 103). Login to comment
528 ABCC7 p.Asp836*
X
ABCC7 p.Asp836* 9922375:528:18
status: NEW
view ABCC7 p.Asp836* details
The activation of D836X Cl0 channels by PKA indicates that E. A Model of R Domain Functionthe MSD1-NBD1 motif must contain many of the sequences with which the R domain interacts to control CFTR. Login to comment
529 ABCC7 p.Asp836*
X
ABCC7 p.Asp836* 9922375:529:32
status: NEW
view ABCC7 p.Asp836* details
The PKA-independent activity of D836X Cl0 chan- The R domain was originally proposed to regulate CFTR by keeping the channel closed at rest. Login to comment
533 ABCC7 p.Ser660Ala
X
ABCC7 p.Ser660Ala 9922375:533:201
status: NEW
view ABCC7 p.Ser660Ala details
ABCC7 p.Asp836*
X
ABCC7 p.Asp836* 9922375:533:47
status: NEW
view ABCC7 p.Asp836* details
Alternatively, the PKA-independent activity of D836X could be due to As described above, phosphorylation by PKA, deletion of FIG. 11 Effect of a recombinant R domain (R1, residues 645-834) on CFTRDR/S660A channel in presence of PKA. Login to comment
535 ABCC7 p.Ser660Ala
X
ABCC7 p.Ser660Ala 9922375:535:77
status: NEW
view ABCC7 p.Ser660Ala details
B and C: effect of R1 on rates of entry into and exit from burst for CFTR-DR/S660A channels in presence of PKA. Login to comment