ABCC7 p.Pro99Gly
| ClinVar: |
c.296C>T
,
p.Pro99Leu
?
, not provided
|
| CF databases: |
c.296C>T
,
p.Pro99Leu
(CFTR1)
?
, This mutation was found together with [delta]F508 in a patient with extreme mild symptoms. It was found by SSCP and sequencing.
|
| Predicted by SNAP2: | A: D (85%), C: D (85%), D: D (80%), E: D (95%), F: D (91%), G: D (91%), H: D (91%), I: D (91%), K: D (95%), L: D (91%), M: D (91%), N: D (91%), Q: D (91%), R: D (95%), S: D (85%), T: D (85%), V: D (91%), W: D (95%), Y: D (91%), |
| Predicted by PROVEAN: | A: D, C: D, D: D, E: D, F: D, G: D, H: D, I: D, K: D, L: D, M: D, N: D, Q: D, R: D, S: D, T: D, V: D, W: D, Y: D, |
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[hide] Structure and function of the CFTR chloride channe... Physiol Rev. 1999 Jan;79(1 Suppl):S23-45. Sheppard DN, Welsh MJ
Structure and function of the CFTR chloride channel.
Physiol Rev. 1999 Jan;79(1 Suppl):S23-45., [PMID:9922375]
Abstract [show]
Structure and Function of the CFTR Chloride Channel. Physiol. Rev. 79, Suppl.: S23-S45, 1999. - The cystic fibrosis transmembrane conductance regulator (CFTR) is a unique member of the ABC transporter family that forms a novel Cl- channel. It is located predominantly in the apical membrane of epithelia where it mediates transepithelial salt and liquid movement. Dysfunction of CFTR causes the genetic disease cystic fibrosis. The CFTR is composed of five domains: two membrane-spanning domains (MSDs), two nucleotide-binding domains (NBDs), and a regulatory (R) domain. Here we review the structure and function of this unique channel, with a focus on how the various domains contribute to channel function. The MSDs form the channel pore, phosphorylation of the R domain determines channel activity, and ATP hydrolysis by the NBDs controls channel gating. Current knowledge of CFTR structure and function may help us understand better its mechanism of action, its role in electrolyte transport, its dysfunction in cystic fibrosis, and its relationship to other ABC transporters.
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No. Sentence Comment
124 When the basic arginine at this position was re- gle-channel Cl0 conductance in the rank order: wild type ' P99G ú P99L ' P99A (119).
X
ABCC7 p.Pro99Gly 9922375:124:108
status: NEW[hide] Contribution of proline residues in the membrane-s... J Biol Chem. 1996 Jun 21;271(25):14995-5001. Sheppard DN, Travis SM, Ishihara H, Welsh MJ
Contribution of proline residues in the membrane-spanning domains of cystic fibrosis transmembrane conductance regulator to chloride channel function.
J Biol Chem. 1996 Jun 21;271(25):14995-5001., [PMID:8663008]
Abstract [show]
Proline residues located in membrane-spanning domains of transport proteins are thought to play an important structural role. In the cystic fibrosis transmembrane conductance regulator (CFTR), the predicted transmembrane segments contain four prolines: Pro99, Pro205, Pro324, and Pro1021. These residues are conserved across species, and mutations of two (P99L and P205S) are associated with cystic fibrosis. To evaluate the contribution of these prolines to CFTR Cl- channel function, we mutated each residue individually to either alanine or glycine or mutated all four simultaneously to alanine (P-Quad-A). We also constructed the two cystic fibrosis-associated mutations. cAMP agonists stimulated whole cell Cl- currents in HeLa cells expressing the individual constructs that resembled those produced by wild-type CFTR. However, the amount of current was decreased in the rank order: wild-type CFTR = Pro324 > Pro1021 > Pro99 >/= Pro205 mutants. The anion selectivity sequence of the mutants (Br- >/= Cl- > I-) resembled wild-type except for P99L (Br- >/= Cl- = I-). Although the Pro99, Pro324, and Pro1021 mutants produced mature protein, the amount of mature protein was much reduced with the Pro205 mutants, and the P-Quad-A made none. Because the Pro99 constructs produced mature protein but had altered whole cell currents, we investigated their single-channel properties. Mutant channels were regulated like wild-type CFTR; however, single-channel conductance was decreased in the rank order: wild-type CFTR >/= P99G > P99L >/= P99A. These results suggest that proline residues in the transmembrane segments are important for CFTR function, Pro205 is critical for correct protein processing, and Pro99 may contribute either directly or indirectly to the Cl- channel pore.
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No. Sentence Comment
9 Mutant channels were regulated like wild-type CFTR; however, single-channel conductance was decreased in the rank order: wild-type CFTR P99G > P99L P99A.
X
ABCC7 p.Pro99Gly 8663008:9:136
status: NEW77 As an example, Fig. 2 shows data from studies of P99A, P99G, and P99L; qualitatively similar results were obtained with the Pro205 , Pro324 , and Pro1021 mutants (data not shown).
X
ABCC7 p.Pro99Gly 8663008:77:55
status: NEW119 Reversal potentials (Erev) of baseline subtracted cAMP-activated whole cell currents were P99A, -30 Ϯ 1 mV (n ϭ 7); P99G, -34 Ϯ 2 mV (n ϭ 5); and P99L, -24 Ϯ 3 mV (n ϭ 6).
X
ABCC7 p.Pro99Gly 8663008:119:128
status: NEW122 Mutant n Px/PCl Gx/GCl Br- Cl- IBr- ClI- CFTR 5 1.18 Ϯ 0.08 1.00 0.73 Ϯ 0.05 1.27 Ϯ 0.16 1.00 0.61 Ϯ 0.08 P99A 7 0.98 Ϯ 0.03 1.00 0.70 Ϯ 0.06 1.04 Ϯ 0.05 1.00 0.72 Ϯ 0.05 P99G 5 1.06 Ϯ 0.02 1.00 0.75 Ϯ 0.08 1.04 Ϯ 0.07 1.00 0.66 Ϯ 0.05 P99L 5 1.21 Ϯ 0.07 1.00 1.06 Ϯ 0.07 1.33 Ϯ 0.11 1.00 0.95 Ϯ 0.08 P205A 4 1.09 Ϯ 0.07 1.00 0.64 Ϯ 0.09 0.95 Ϯ 0.04 1.00 0.46 Ϯ 0.11 P205G 5 1.09 Ϯ 0.05 1.00 0.45 Ϯ 0.05 1.05 Ϯ 0.03 1.00 0.44 Ϯ 0.06 P205S 2 1.01 Ϯ 0.01 1.00 0.55 Ϯ 0.28 1.09 Ϯ 0.09 1.00 0.59 Ϯ 0.08 P324A 7 1.08 Ϯ 0.04 1.00 0.72 Ϯ 0.06 1.15 Ϯ 0.07 1.00 0.60 Ϯ 0.08 P324G 6 1.12 Ϯ 0.07 1.00 0.69 Ϯ 0.04 1.22 Ϯ 0.14 1.00 0.57 Ϯ 0.04 P1021A 3 1.15 Ϯ 0.17 1.00 0.73 Ϯ 0.11 1.17 Ϯ 0.10 1.00 0.47 Ϯ 0.19 P1021G 7 1.17 Ϯ 0.06 1.00 0.78 Ϯ 0.02 1.21 Ϯ 0.08 1.00 0.59 Ϯ 0.06 though for P99G the reduction was small, for P99A and P99L the effect was marked.
X
ABCC7 p.Pro99Gly 8663008:122:219
status: NEWX
ABCC7 p.Pro99Gly 8663008:122:1041
status: NEW126 The conductance for P99G was 7.31 Ϯ 0.24 pS (n ϭ 5), not significantly different from wild type (p ϭ 0.26).
X
ABCC7 p.Pro99Gly 8663008:126:20
status: NEWX
ABCC7 p.Pro99Gly 8663008:126:175
status: NEWX
ABCC7 p.Pro99Gly 8663008:126:781
status: NEW145 The number of cells responding to cAMP agonists with Cl- current activation relative to the total number of cells tested for each construct was: CFTR (8/16; 50%), P99A (11/12; 92%), P99G (9/19; 47%), P99L (10/19; 53%), P205A (7/12; 58%), P205G (5/9; 56%), P205S (7/20; 35%), P324A (9/18; 50%), P324G (9/22; 41%), P1021A (8/18; 44%), and P1021G (7/16; 44%).
X
ABCC7 p.Pro99Gly 8663008:145:182
status: NEW176 Similar results were observed with P99G and P99L; n Ͼ 5 for each mutant.
X
ABCC7 p.Pro99Gly 8663008:176:35
status: NEW177 B, representative single-channel recordings are from excised inside-out membrane patches from HeLa cells transiently expressing wild-type CFTR, P99A, P99G, and P99L.
X
ABCC7 p.Pro99Gly 8663008:177:150
status: NEW180 C, single-channel I-V relationships of CFTR (circles), P99A (squares), P99G (triangles), and P99L (inverted triangles.
X
ABCC7 p.Pro99Gly 8663008:180:71
status: NEW199 Substitution of alanine, glycine, and leucine at Pro99 decreased single-channel conductance in the rank order: wild-type CFTR Ն P99G Ͼ P99L Ն P99A.
X
ABCC7 p.Pro99Gly 8663008:199:134
status: NEW202 Glycine, which is found in hinge regions and like proline is not favored in ␣-helices, can substitute for proline at this residue because the single-channel conductance of P99G does not differ from wild type.
X
ABCC7 p.Pro99Gly 8663008:202:179
status: NEW78 As an example, Fig. 2 shows data from studies of P99A, P99G, and P99L; qualitatively similar results were obtained with the Pro205 , Pro324 , and Pro1021 mutants (data not shown).
X
ABCC7 p.Pro99Gly 8663008:78:55
status: NEW123 Reversal potentials (Erev) of baseline subtracted cAMP-activated whole cell currents were P99A, 230 6 1 mV (n 5 7); P99G, 234 6 2 mV (n 5 5); and P99L, 224 6 3 mV (n 5 6).
X
ABCC7 p.Pro99Gly 8663008:123:116
status: NEW130 The conductance for P99G was 7.31 6 0.24 pS (n 5 5), not significantly different from wild type (p 5 0.26).
X
ABCC7 p.Pro99Gly 8663008:130:20
status: NEW149 The number of cells responding to cAMP agonists with Cl2 current activation relative to the total number of cells tested for each construct was: CFTR (8/16; 50%), P99A (11/12; 92%), P99G (9/19; 47%), P99L (10/19; 53%), P205A (7/12; 58%), P205G (5/9; 56%), P205S (7/20; 35%), P324A (9/18; 50%), P324G (9/22; 41%), P1021A (8/18; 44%), and P1021G (7/16; 44%).
X
ABCC7 p.Pro99Gly 8663008:149:182
status: NEW181 Similar results were observed with P99G and P99L; n .
X
ABCC7 p.Pro99Gly 8663008:181:35
status: NEW183 B, representative single-channel recordings are from excised inside-out membrane patches from HeLa cells transiently expressing wild-type CFTR, P99A, P99G, and P99L.
X
ABCC7 p.Pro99Gly 8663008:183:150
status: NEW186 C, single-channel I-V relationships of CFTR (circles), P99A (squares), P99G (triangles), and P99L (inverted triangles.
X
ABCC7 p.Pro99Gly 8663008:186:71
status: NEW205 Substitution of alanine, glycine, and leucine at Pro99 decreased single-channel conductance in the rank order: wild-type CFTR $ P99G .
X
ABCC7 p.Pro99Gly 8663008:205:128
status: NEW210 Glycine, which is found in hinge regions and like proline is not favored in a-helices, can substitute for proline at this residue because the single-channel conductance of P99G does not differ from wild type.
X
ABCC7 p.Pro99Gly 8663008:210:172
status: NEW