ABCMdb

ABCG2 p.Met549Ala

Predicted by SNAP2:	A: D (66%), C: D (63%), D: D (91%), E: D (85%), F: D (71%), G: D (80%), H: D (85%), I: N (57%), K: D (91%), L: N (53%), N: D (80%), P: D (91%), Q: D (75%), R: D (91%), S: D (80%), T: D (71%), V: N (53%), W: D (85%), Y: D (75%),
Predicted by PROVEAN:	A: D, C: D, D: D, E: D, F: D, G: D, H: D, I: N, K: D, L: N, N: D, P: D, Q: D, R: D, S: D, T: D, V: N, W: D, Y: D,

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Publications
[hide] Identification of residues in ABCG2 affecting prot... Biosci Rep. 2015 Jul 17;35(4). pii: e00241. doi: 10.1042/BSR20150150. Haider AJ, Cox MH, Jones N, Goode AJ, Bridge KS, Wong K, Briggs D, Kerr ID
Identification of residues in ABCG2 affecting protein trafficking and drug transport, using co-evolutionary analysis of ABCG sequences.
Biosci Rep. 2015 Jul 17;35(4). pii: e00241. doi: 10.1042/BSR20150150., [PMID:26294421]

Abstract [show]
ABCG2 is an ABC (ATP-binding cassette) transporter with a physiological role in urate transport in the kidney and is also implicated in multi-drug efflux from a number of organs in the body. The trafficking of the protein and the mechanism by which it recognizes and transports diverse drugs are important areas of research. In the current study, we have made a series of single amino acid mutations in ABCG2 on the basis of sequence analysis. Mutant isoforms were characterized for cell surface expression and function. One mutant (I573A) showed disrupted glycosylation and reduced trafficking kinetics. In contrast with many ABC transporter folding mutations which appear to be 'rescued' by chemical chaperones or low temperature incubation, the I573A mutation was not enriched at the cell surface by either treatment, with the majority of the protein being retained in the endoplasmic reticulum (ER). Two other mutations (P485A and M549A) showed distinct effects on transport of ABCG2 substrates reinforcing the role of TM helix 3 in drug recognition and transport and indicating the presence of intracellular coupling regions in ABCG2.

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Sentences [show]
No. Sentence Comment
8 Two other mutations (P485A and M549A) showed distinct effects on transport of ABCG2 substrates reinforcing the role of TM helix 3 in drug recognition and transport and indicating the presence of intracellular coupling regions in ABCG2. Login to comment
109 We made individual substitutions of each amino acid to alanine: M131A, S195A, K453A, K473A, P485A, M549A, W564A and I573A. Login to comment
154 Secondly, there were a pair of mutant isoforms which showed little or no FTC-mediated inhibition of MX export (i.e. having high accumulation of MX even in the absence of FTC) but normal ABCG2 surface protein expression (P485A and M549A; P485A data shown in Figure 5D). Login to comment
156 To investigate further the two TMD mutations with impaired drug transport (M549A and P485A), we generated stable expressing cell lines expressing sfGFP-tagged isoforms. Login to comment
172 sfGFP-M549A and the catalytically inactive sfGFP-K86A isoform showed no Ko143-inhibited MX transport. Login to comment
173 With PhA, neither sfGFP-K86A nor sfGFP-M549A showed Ko143-inhibitable transport. Login to comment
179 Of the eight residues we mutated, two resulted in altered drug export function (P485A and M549A) and a further residue (I573A) perturbs the trafficking and maturation of ABCG2 glycosylation. Login to comment
193 Two of the remaining residues we mutated (M549A and P485A) affected drug export and provide some further evidence for a role for TM3 in forming part of a drug-binding site on ABCG2. Login to comment
206 9 to determine whether the lack of function of the P485A and M549A isoforms is due to impaired substrate binding (i.e. a direct effect on the drug-binding site) and/or impaired TMD-NBD communication. Login to comment