ABCC7 p.Lys14Arg
ClinVar: |
c.40A>T
,
p.Lys14*
?
, not provided
|
Predicted by SNAP2: | A: N (53%), C: D (59%), D: D (75%), E: D (63%), F: D (59%), G: D (66%), H: N (61%), I: N (57%), L: N (57%), M: D (63%), N: N (72%), P: D (80%), Q: N (78%), R: N (93%), S: N (61%), T: N (57%), V: D (66%), W: D (80%), Y: D (53%), |
Predicted by PROVEAN: | A: N, C: D, D: D, E: N, F: D, G: D, H: N, I: D, L: D, M: N, N: N, P: D, Q: N, R: N, S: N, T: N, V: D, W: D, Y: D, |
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Comments [show]
None has been submitted yet.
[hide] Interference with ubiquitination in CFTR modifies ... Mol Cell Biol. 2014 Jul;34(14):2554-65. Lee S, Henderson MJ, Schiffhauer E, Despanie J, Henry K, Kang PW, Walker D, McClure ML, Wilson L, Sorscher EJ, Zeitlin PL
Interference with ubiquitination in CFTR modifies stability of core glycosylated and cell surface pools.
Mol Cell Biol. 2014 Jul;34(14):2554-65., [PMID:24777605]
Abstract [show]
It is recognized that both wild-type and mutant CFTR proteins undergo ubiquitination at multiple lysines in the proteins and in one or more subcellular locations. We hypothesized that ubiquitin is added to specific sites in wild-type CFTR to stabilize it and at other sites to signal for proteolysis. Mass spectrometric analysis of wild-type CFTR identified ubiquitinated lysines 68, 710, 716, 1041, and 1080. We demonstrate that the ubiquitinated K710, K716, and K1041 residues stabilize wild-type CFTR, protecting it from proteolysis. The polyubiquitin linkage is predominantly K63. N-tail mutants, K14R and K68R, lead to increased mature band CCFTR, which can be augmented by proteasomal (but not lysosomal) inhibition, allowing trafficking to the surface. The amount of CFTR in the K1041R mutant was drastically reduced and consisted of bands A/B, suggesting that the site in transmembrane 10 (TM10) was critical to further processing beyond the proteasome. The K1218R mutant increases total and cell surface CFTR, which is further accumulated by proteasomal and lysosomal inhibition. Thus, ubiquitination at residue 1218 may destabilize wild-type CFTR in both the endoplasmic reticulum (ER) and recycling pools. Small molecules targeting the region of residue 1218 to block ubiquitination or to preserving structure at residues 710 to 716 might be protein sparing for some forms of cystic fibrosis.
Comments [show]
None has been submitted yet.
No. Sentence Comment
5 N-tail mutants, K14R and K68R, lead to increased mature band C CFTR, which can be augmented by proteasomal (but not lysosomal) inhibition, allowing trafficking to the surface.
X
ABCC7 p.Lys14Arg 24777605:5:16
status: NEW73 We hypothe- TABLE 1 Primers for site-directed mutagenesis Mutation Directiona Sequence (5=-3=)b K14R F GGCCAGCGTTGTCTCCAGACTTTTTTTCAGCTGGACC R GGTCCAGCTGAAAAAAAGTCTGGAGACAACGCTGGCC K68R F GGCTTCAAAGAAAAATCCTAGACTCATTAATGCCCTTCGGCG R CGCCGAAGGGCATTAATGAGTCTAGGATTTTTCTTTGAAGCC K710R F CCAATCAACTCTATACGAAGATTTTCCATTGTGCAAAAG R CTTTTGCACAATGGAAAATCTTCGTATAGAGTTGATTGG K716R F GAAAATTTTCCATTGTGCAAAGGACTCCCTTACAAATGAATGG R CCATTCATTTGTAAGGGAGTCCTTTGCACAATGGAAAATTTTC K710/716R F CCAATCAACTCTATACGAAGATTTTCCATTGTGCAAAGGACTCCCTTACAAATGAATGG R CCATTCATTTGTAAGGGAGTCCTTTGCACAATGGAAAATCTTCGTATAGAGTTGATTGG K1041R F CCTCACAGCAATTCAGACAACTGGAATCTGAAG R CTTCAGATTCCAGTTGTCTGAGTTGCTGTGAGG K1080R F GAAACTCTGTTCCACAGAGCTCTGAATTTACATAC R GTATGTAAATTCAGAGCTCTGTGGAACAGAGTTTC K1218R F GATCTCACAGCAAGATACACAGAAGG R CCTTCTGTGTATCTTGCTGTGAGATC a F, forward; R, reverse.
X
ABCC7 p.Lys14Arg 24777605:73:96
status: NEW99 K14R and K68R mutations result in increased levels of immature (A/B band) and mature (C band) forms of CFTR expression (Fig. 2B).
X
ABCC7 p.Lys14Arg 24777605:99:0
status: NEW117 To test this hypothesis for K14R and K68R, we expressed these N-tail mutants in the presence and absence of proteasomal inhibition.
X
ABCC7 p.Lys14Arg 24777605:117:28
status: NEW119 4A), but proteasome inhibition during expression of the K14R and K68R mutant CFTR cDNAs led to even higher expression levels.
X
ABCC7 p.Lys14Arg 24777605:119:56
status: NEW130 This immunoblot demonstrates increased levels of band C CFTR expression from the K14R, K68R, and K1218R cDNA vectors and decreased levels of band C CFTR expression in K710R, K716R, K710/716R, and K1080R vectors.
X
ABCC7 p.Lys14Arg 24777605:130:81
status: NEW135 However, unexpectedly, expression levels in K14R- and K68R- transfected cells were not increased by lysosomal inhibition, perhaps because they were already slow to recycle.
X
ABCC7 p.Lys14Arg 24777605:135:44
status: NEW136 Densitometry analysis showed that a proteasomal inhibitor increased C bands of wt, K14R, and K68R compared to control levels, but changes in A/B bands were insignificant.
X
ABCC7 p.Lys14Arg 24777605:136:83
status: NEW137 Lysosomal inhibitor did not change C bands, but A/B bands of K14R and K68R were decreased compared to control levels.
X
ABCC7 p.Lys14Arg 24777605:137:61
status: NEW138 These data suggest that K14R and K68R mutations allow CFTR to bypass the lysosome for degradation so that preventing lysosomal activity does not further increase the expression level of the mutant compared to wild-type CFTR.
X
ABCC7 p.Lys14Arg 24777605:138:24
status: NEW163 (A) The results from expression of control vector, wt CFTR, K14R, and K68R with and without proteasomal or lysosomal inhibition are shown in representative blots.
X
ABCC7 p.Lys14Arg 24777605:163:60
status: NEW164 MG132 increased total A/B/C bands of CFTR in wild-type, K14R, and K68R proteins.
X
ABCC7 p.Lys14Arg 24777605:164:56
status: NEW194 K14R, K1080R, and K1218R but not K1041R reach the cell surface.
X
ABCC7 p.Lys14Arg 24777605:194:0
status: NEW200 There were decreased levels of cell surface CFTR detection in the K68R, K710R, K716R, K710/ K716R, and K1041R mutant forms of CFTR, but the wild-type, K14R, K1080R, and K1218R mutants accumulated similar levels of visible cell surface CFTR.
X
ABCC7 p.Lys14Arg 24777605:200:151
status: NEW207 Again, there was a reduction in immunodetectable CFTR (K14R, K68R, K710R, K716R, K710/716R, and K1080R forms) in cell surface membranes compared to wild-type levels.
X
ABCC7 p.Lys14Arg 24777605:207:55
status: NEW214 Preventing ubiquitination at K14R, K1080R, and K1218R allows the mutant protein to gain access to the cell surface.
X
ABCC7 p.Lys14Arg 24777605:214:29
status: NEW218 Control vector, wt CFTR, K14R, K68R, K710R, K716R, K710/716R, K1041R, K1080R, and K1218R were expressed in IB3-1 cells for 48 h. CFTR was immunoprecipitated (IP) with M3A7 as described in Materials and Methods and separated by SDS-PAGE.
X
ABCC7 p.Lys14Arg 24777605:218:25
status: NEW226 FIG 6 K-to-R mutation alters the stability of CFTR protein, and wt CFTR, K14R, K1080R, and K1218R, but not K1041R, are detectable at the cell surface.
X
ABCC7 p.Lys14Arg 24777605:226:73
status: NEW252 The F508del from the surface of cells expressing wt CFTR, K14R, K1080R, and K1218R.
X
ABCC7 p.Lys14Arg 24777605:252:58
status: NEW275 Since ZO-1 interacts with PDZ domains, the reduced interactions in K14R, K68R, K710R, K716R, K710/716R, and K1041R and the absence of interactions with K1080R and K1218R raise the issue of alternative trafficking routes that are not dependent on the C-tail PDZ domain.
X
ABCC7 p.Lys14Arg 24777605:275:67
status: NEW279 K14R and K68R experience some proteasome degradation, but a sizeable fraction is localized near the plasma membrane.
X
ABCC7 p.Lys14Arg 24777605:279:0
status: NEW296 Interestingly, ZO-1 was highly abundant in complexes formed with wt CFTR; K14R, K68R, K710R, K716R, K710/716R, and K1041R mutants bound less ZO-1, whereas K1080R and K1218R mutant complexes had none.
X
ABCC7 p.Lys14Arg 24777605:296:74
status: NEW