ABCB11 p.Tyr1311Ala
| Predicted by SNAP2: | A: D (63%), C: D (53%), D: D (85%), E: D (85%), F: N (87%), G: D (80%), H: N (72%), I: D (75%), K: D (75%), L: D (75%), M: D (66%), N: D (75%), P: D (91%), Q: D (66%), R: D (53%), S: N (61%), T: D (71%), V: D (71%), W: N (78%), |
| 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: D, |
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[hide] Differential roles of ubiquitination in the degrad... Mol Pharmacol. 2014 Mar;85(3):482-91. doi: 10.1124/mol.113.091090. Epub 2013 Dec 30. Aida K, Hayashi H, Inamura K, Mizuno T, Sugiyama Y
Differential roles of ubiquitination in the degradation mechanism of cell surface-resident bile salt export pump and multidrug resistance-associated protein 2.
Mol Pharmacol. 2014 Mar;85(3):482-91. doi: 10.1124/mol.113.091090. Epub 2013 Dec 30., [PMID:24378332]
Abstract [show]
We previously showed that ubiquitination, a reversible post-translational modification, facilitates degradation of cell surface-resident bile salt export pump (BSEP) and multidrug resistance-associated protein 2 (MRP2), ABC transporters that are expressed at the canalicular membrane (CM) of hepatocytes. In the current study, its underlying mechanism was investigated by evaluating the role of ubiquitination in the processes of internalization and subsequent degradation of cell surface-resident BSEP and MRP2. Cell surface biotinylation analysis using Flp-In T-REx 293 cells showed that ectopic expression of Ub(Delta)(GG), which is ubiquitin (Ub) lacking the two C-terminal glycines essential for the Ub conjugation reaction, inhibited the internalization of 3x FLAG-BSEP, but not of MRP2, and the degradation of the internalized MRP2, but not of the internalized 3x FLAG-BSEP. Its inhibitory effect on BSEP internalization was also indicated by a time-lapse imaging analysis using the rat hepatoma cell line McA-RH7777 in which Ub(Delta)(GG) delayed the loss of fluorescence from photoactivated Dronpa-BSEP on the CM. The effect of Ub(Delta)(GG) on BSEP internalization in these experiments was abrogated by treatment with chlorpromazine, an inhibitor of clathrin-mediated endocytosis, and the introduction of a Y1311A mutation into BSEP. This mutation eliminates the ability of BSEP to interact with the AP2 adaptor complex, an adaptor protein required for cargo selection in clathrin-mediated endocytosis. In conclusion, our data suggest that ubiquitination facilitates clathrin-mediated endocytosis of BSEP and the degradation of internalized MRP2, leading to the degradation of the cell surface-resident form of both transporters.
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No. Sentence Comment
4 The effect of UbDGG on BSEP internalization in these experiments was abrogated by treatment with chlorpromazine, an inhibitor of clathrin-mediated endocytosis, and the introduction of a Y1311A mutation into BSEP.
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ABCB11 p.Tyr1311Ala 24378332:4:186
status: NEW28 The cDNAs for human 3 FLAG-BSEP; 3 FLAG-BSEPY1311A , which incorporates a Y1311A mutation into 3 FLAG-BSEP; and MRP2 were cloned into pShuttle (Clontech, Mountain View, CA) (pShuttle-3 FLAG-BSEP and pShuttle-3 FLAG-BSEPY1311A ) and pcDNA3.1(1)-Neo (Invitrogen) (pcDNA3.1(1)-MRP2), respectively, as described previously (Hayashi et al., 2012a,b).
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ABCB11 p.Tyr1311Ala 24378332:28:76
status: NEW97 Elimination of the Inhibitory Effect of HA-UbDGG on the Internalization of 33 FLAG-BSEP by Treatment with Chlorpromazine and Introduction of a Y1311A Mutation.
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ABCB11 p.Tyr1311Ala 24378332:97:143
status: NEW