ABCC7 p.Tyr512Glu
| Predicted by SNAP2: | A: D (80%), C: D (71%), D: D (91%), E: D (91%), F: D (59%), G: D (91%), H: N (53%), I: D (75%), K: D (91%), L: D (53%), M: N (61%), N: D (85%), P: D (91%), Q: D (80%), R: D (91%), S: D (85%), T: D (85%), V: D (80%), W: D (66%), |
| Predicted by PROVEAN: | A: D, C: D, D: D, E: D, F: N, G: D, H: D, I: D, K: D, L: D, M: D, N: D, P: D, Q: D, R: D, S: D, T: D, V: D, W: N, |
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[hide] Antagonistic Regulation of Cystic Fibrosis Transme... Mol Cell Biol. 2011 Oct;31(19):4076-86. Epub 2011 Aug 1. Mendes AI, Matos P, Moniz S, Luz S, Amaral MD, Farinha CM, Jordan P
Antagonistic Regulation of Cystic Fibrosis Transmembrane Conductance Regulator Cell Surface Expression by Protein Kinases WNK4 and Spleen Tyrosine Kinase.
Mol Cell Biol. 2011 Oct;31(19):4076-86. Epub 2011 Aug 1., [PMID:21807898]
Abstract [show]
Members of the WNK (with-no-lysine [K]) subfamily of protein kinases regulate various ion channels involved in sodium, potassium, and chloride homeostasis by either inducing their phosphorylation or regulating the number of channel proteins expressed at the cell surface. Here, we describe findings demonstrating that the cell surface expression of the cystic fibrosis transmembrane conductance regulator (CFTR) is also regulated by WNK4 in mammalian cells. This effect of WNK4 is independent of the presence of kinase and involves interaction with and inhibition of spleen tyrosine kinase (Syk), which phosphorylates Tyr512 in the first nucleotide-binding domain 1 (NBD1) of CFTR. Transfection of catalytically active Syk into CFTR-expressing baby hamster kidney cells reduces the cell surface expression of CFTR, whereas that of WNK4 promotes it. This is shown by biotinylation of cell surface proteins, immunofluorescence microscopy, and functional efflux assays. Mutation of Tyr512 to either glutamic acid or phenylalanine is sufficient to alter CFTR surface levels. In human airway epithelial cells, downregulation of endogenous Syk and WNK4 confirms their roles as physiologic regulators of CFTR surface expression. Together, our results show that Tyr512 phosphorylation is a novel signal regulating the prevalence of CFTR at the cell surface and that WNK4 and Syk perform an antagonistic role in this process.
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No. Sentence Comment
10 Mutation of Tyr512 to either glutamic acid or37 phenylalanine is sufficient to alter CFTR surface levels.
X
ABCC7 p.Tyr512Glu 21807898:10:12
status: NEW138 CFTR-Y512E expressing cells showed a significant506 decrease in CFTR-mediated ion transport while cells expressing CFTR Y512F507 released almost twice the amount of iodide as wt CFTR-expressing cells.
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ABCC7 p.Tyr512Glu 21807898:138:5
status: NEW142 Second, cells were co-transfected with the phospho-mimetic CFTR-516 Y512E mutant and Myc-WNK4-wt.
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ABCC7 p.Tyr512Glu 21807898:142:68
status: NEW143 Under these conditions, the expression of517 WNK4 was unable to rescue surface levels of the CFTR-Y512E mutant protein518 (FIG. 8B, two right lanes) to those of wt CFTR (second lane from left).519 520 521 DISCUSSION522 523 The data presented in this work provide two novel insights into the regulation of524 cell surface expression of CFTR.
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ABCC7 p.Tyr512Glu 21807898:143:98
status: NEW