Identification of residues in ABCG2 affecting protein trafficking and drug transport, using co-evolutionary analysis of ABCG sequences

TY - JOUR

T1 - Identification of residues in ABCG2 affecting protein trafficking and drug transport, using co-evolutionary analysis of ABCG sequences

AU - Haider, Ameena J

AU - Cox, Megan H

AU - Jones, Natalie

AU - Goode, Alice J

AU - Bridge, Katherine S

AU - Wong, Kelvin

AU - Briggs, Deborah

AU - Kerr, Ian D

N1 - © 2015 Authors.

PY - 2018/8/1

Y1 - 2018/8/1

N2 - 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.

AB - 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.

KW - ATP Binding Cassette Transporter, Subfamily G, Member 2

KW - ATP-Binding Cassette Transporters/genetics

KW - Amino Acid Substitution

KW - Directed Molecular Evolution

KW - HEK293 Cells

KW - Humans

KW - Mutation, Missense

KW - Neoplasm Proteins/genetics

KW - Protein Transport

U2 - 10.1042/BSR20150150

DO - 10.1042/BSR20150150

M3 - Article

C2 - 26294421

SN - 0144-8463

VL - 35

JO - Bioscience Reports

JF - Bioscience Reports

IS - 4

M1 - e00241

ER -