ABCC7 p.Leu1480Val
| CF databases: |
c.4439T>C
,
p.Leu1480Pro
(CFTR1)
?
, The mutation was detected by DGGE analysis and characterized by direct sequencing. We have seen it only twice, in over 2000 control chromosomes from Italian population.
|
| Predicted by SNAP2: | A: N (53%), C: N (61%), D: D (59%), E: D (53%), F: N (57%), G: D (63%), H: D (53%), I: N (72%), K: D (59%), M: N (78%), N: D (53%), P: D (66%), Q: N (61%), R: D (63%), S: N (53%), T: N (57%), V: N (78%), W: D (59%), Y: N (53%), |
| Predicted by PROVEAN: | A: N, C: N, D: N, E: N, F: N, G: N, H: N, I: N, K: N, M: N, N: N, P: N, Q: N, R: N, S: N, T: N, V: N, W: N, Y: N, |
[switch to compact view]
Comments [show]
None has been submitted yet.
[hide] Regulation of cystic fibrosis transmembrane conduc... Proc Natl Acad Sci U S A. 2001 Jan 30;98(3):1300-5. Epub 2001 Jan 23. Raghuram V, Mak DO, Foskett JK
Regulation of cystic fibrosis transmembrane conductance regulator single-channel gating by bivalent PDZ-domain-mediated interaction.
Proc Natl Acad Sci U S A. 2001 Jan 30;98(3):1300-5. Epub 2001 Jan 23., 2001-01-30 [PMID:11158634]
Abstract [show]
The cystic fibrosis transmembrane conductance regulator (CFTR) is a cAMP-dependent protein kinase- and ATP-regulated chloride channel, the activity of which determines the rate of electrolyte and fluid transport in a variety of epithelial tissues. Here we describe a mechanism that regulates CFTR channel activity, which is mediated by PDZ domains, a family of conserved protein-interaction modules. The Na(+)/H(+) exchanger regulatory factor (NHERF) binds to the cytoplasmic tail of CFTR through either of its two PDZ (PDZ1 and PDZ2) domains. A recombinant fragment of NHERF (PDZ1-2) containing the two PDZ domains increases the open probability (P(o)) of single CFTR channels in excised membrane patches from a lung submucosal gland cell line. Both PDZ domains are required for this functional effect, because peptides containing mutations in either domain are unable to increase channel P(o). The concentration dependence of the regulation by the bivalent PDZ1-2 domain is biphasic, i.e., activating at lower concentrations and inhibiting at higher concentrations. Furthermore, either PDZ domain alone or together is without effect on P(o), but either domain can competitively inhibit the PDZ1-2-mediated stimulation of CFTR. Our results support a molecular model in which bivalent NHERF PDZ domains regulate channel gating by crosslinking the C-terminal tails in a single dimeric CFTR channel, and the magnitude of this regulation is coupled to the stoichiometry of these interactions.
Comments [show]
None has been submitted yet.
No. Sentence Comment
110 The mutation L1480A resulted in a complete loss of interaction, and mutations T1378A, L1480V, and L1480M resulted in markedly reduced interaction (Fig. 1D), with both PDZ1 and PDZ2 having similar specificities for their target ligands.
X
ABCC7 p.Leu1480Val 11158634:110:86
status: NEW[hide] Improved maturation of CFTR by an ER export signal... FASEB J. 2007 Aug;21(10):2352-8. Epub 2007 Mar 28. Wendeler MW, Nufer O, Hauri HP
Improved maturation of CFTR by an ER export signal.
FASEB J. 2007 Aug;21(10):2352-8. Epub 2007 Mar 28., [PMID:17392477]
Abstract [show]
The cystic fibrosis transmembrane conductance regulator (CFTR) is a cAMP-regulated chloride channel in the plasma membrane of several epithelial cells. Maturation of CFTR is inefficient in most cells, with only a fraction of nascent chains being properly folded and transported to the cell surface. The most common mutation in CFTR, CFTR-deltaF508, leads to the genetic disease cystic fibrosis. CFTR-deltaF508 has a temperature-sensitive folding defect and is almost quantitatively degraded in the endoplasmic reticulum (ER). Here we tested whether a strong ER export signal appended to CFTR improves its transport and surface expression. We show that a single valine ER export signal at the C terminus of the cytoplasmic tail of CFTR improves maturation of wild-type CFTR by 2-fold. This conservative mutation interfered with neither plasma membrane localization nor stability of mature CFTR. In contrast, the valine signal was unable to rescue CFTR-deltaF508 from ER-associated degradation. Our finding of improved maturation of CFTR mediated by a valine signal may be of potential use in gene therapy of cystic fibrosis. Moreover, failure of the valine signal to rescue CFTR-deltaF508 from ER degradation indicates that the inability of CFTR-deltaF508 to leave the ER is unlikely to be due to a malfunctioning ER export signal.
Comments [show]
None has been submitted yet.
No. Sentence Comment
36 Substitution of the most C-terminal leucine at position 1480 by valine was carried out by QuikChange mutagenesis (Stratagene, San Diego, CA, USA) using complementary oligonucleotides for changing codon CTT to GTT.
X
ABCC7 p.Leu1480Val 17392477:36:36
status: NEW86 The wild-type tail and the modified tail with L1480V mutation (underlined) are shown.
X
ABCC7 p.Leu1480Val 17392477:86:46
status: NEW87 B) HEK293 cells stably expressing wild-type or L1480V mutated CFTR constructs were pulse-labeled with [35 S]methionine for 20 min, chased for the indicated times, and subjected to immunoprecipitation with anti-CFTR antibodies.
X
ABCC7 p.Leu1480Val 17392477:87:47
status: NEW91 Values of CFTR with C) wild-type tail (HEK clone 6) and D) L1480V modified tail (HEK293 clone 1).
X
ABCC7 p.Leu1480Val 17392477:91:59
status: NEW127 A) HEK293 cells stably expressing wild-type or L1480V mutated CFTR constructs were pulse-labeled with [35 S]methionine, chased for the indicated times, and subjected to immunoprecipitation with anti-CFTR antibodies. Immunoprecipitates were then separated by SDS-PAGE and visualized by fluorography. Note that only the complex glycosylated mature form (band C) of CFTR constructs is detected. B) Quantification of fluorograms as shown in panel A.
X
ABCC7 p.Leu1480Val 17392477:127:47
status: NEW128 Black data points indicate the complex glycosylated form of wild-type CFTR and white data points the complex glycosylated form of the CFTR L1480V mutation.
X
ABCC7 p.Leu1480Val 17392477:128:139
status: NEW131 The L1480V substitution not only needs to be discussed in the context of ER export but also because L1480 is part of a PDZ binding motif.
X
ABCC7 p.Leu1480Val 17392477:131:4
status: NEW136 The substitution of leucine 1480 by a valine reported here, however, is a conservative mutation not expected to interfere with PDZ binding, since it meets the PDZ type I consensus sequence S/T-X-V/ I/L/F/Y (43).
X
ABCC7 p.Leu1480Val 17392477:136:20
status: NEW137 Accordingly, protein labeling of intact adherent cells by a membrane-impermeable biotinylation reagent showed that the L1480V substitution did not interfere with surface localization of mature CFTR (Fig. 2).
X
ABCC7 p.Leu1480Val 17392477:137:119
status: NEW163 However, our results showed that the L1480V substitution on CFTR-⌬F508 was not able to overcome the retention of misfolded molecules.
X
ABCC7 p.Leu1480Val 17392477:163:37
status: NEW[hide] Role of CFTR's PDZ1-binding domain, NBF1 and Cl(-)... Biochim Biophys Acta. 2001 Nov 1;1515(1):64-71. Boucherot A, Schreiber R, Kunzelmann K
Role of CFTR's PDZ1-binding domain, NBF1 and Cl(-) conductance in inhibition of epithelial Na(+) channels in Xenopus oocytes.
Biochim Biophys Acta. 2001 Nov 1;1515(1):64-71., [PMID:11597353]
Abstract [show]
The cystic fibrosis transmembrane conductance regulator (CFTR) inhibits epithelial Na(+) channels (ENaC). Evidence has accumulated that both Cl(-) transport through CFTR Cl(-) channels and the first nucleotide binding domain (NBF1) of CFTR are crucial for inhibition of ENaC. A PDZ binding domain (PDZ-BD) at the C-terminal end links CFTR to scaffolding and cytoskeletal proteins, which have been suggested to play an important role in activation of CFTR and eventually inhibition of ENaC. We eliminated the PDZ-BD of CFTR and coexpressed Na(+)/H(+)-exchange regulator factors together with CFTR and ENaC. The results do not support a role of PDZ-BD in inhibition of ENaC by CFTR. However, inhibition of ENaC was closely linked to Cl(-) currents generated by CFTR and was observed in the presence of Cl(-), I(-) or Br(-) but not gluconate. Therefore, functional NBF1 and Cl(-) transport are required for inhibition of ENaC in Xenopus oocytes, while the PDZ-BD is not essential.
Comments [show]
None has been submitted yet.
No. Sentence Comment
63 The C-terminal PDZ-BD of CFTR is not required for activation of CFTR or inhibition of ENaC in Xenopus oocytes The PDZ-BD at the C-terminal end of CFTR was mutated in vitro (L1480V-CFTR) and coexpressed together with the epithelial NaW channel in Xenopus oocytes.
X
ABCC7 p.Leu1480Val 11597353:63:173
status: NEW67 A Cl3 conductance (GCFTR) of similar magnitude was activated in both wtCFTR and L1480V-CFTR expressing oocytes upon stimulation with IBMX and forskolin (I/F).
X
ABCC7 p.Leu1480Val 11597353:67:80
status: NEW74 Original recordings of the whole cell currents measured in a Xenopus oocyte coexpressing L1480V-CFTR and ENaC.
X
ABCC7 p.Leu1480Val 11597353:74:89
status: NEW91 Coexpression of wtCFTR, L1480V-CFTR, E831X-CFTR and E1474X with ENaC.
X
ABCC7 p.Leu1480Val 11597353:91:24
status: NEW94 Stimulation of either wtCFTR, L1480V-CFTR, E831X-CFTR or E1474X signi'cantly enhanced CFTR whole cell Cl3 conductance.
X
ABCC7 p.Leu1480Val 11597353:94:30
status: NEW150 Although the L1480V-CFTR mutant allows only marginal binding of NHERF to CFTR [12], activation of L1480V-CFTR by IBMX and forskolin was comparable to that of wtCFTR and even the N-terminal half of CFTR (E831X) was still partially activated by increase in intracellular cAMP.
X
ABCC7 p.Leu1480Val 11597353:150:13
status: NEWX
ABCC7 p.Leu1480Val 11597353:150:98
status: NEW