title: Mutations adjacent to the end of transmembrane helices 6 and 7 independently affect drug efflux capacity of yeast ABC transporter Pdr5p.
abstract: As a mammalian p-glycoprotein homolog, Pdr5p is a major ATP-binding cassette transporter for cellular detoxification in the yeast Saccharomyces cerevisiae. In this study, two novel loss-of-function mutations located adjacent to the ends of the predicted transmembrane helices of Pdr5p were identified. C793F and S1230L mutations considerably impaired the transport activity of Pdr5p without affecting the ATPase activity and the expression level of the protein. Our results demonstrate that the size of residue 793 and the hydrophobicity of residue 1230 are important for Pdr5p efflux function. It reveals that amino acid residues located near the end of transmembrane helix play an important role in drug efflux of Pdr5p. Molecular docking results further suggest that these two single mutations might have disturbed interactions between the drugs and Pdr5p, preventing the drugs from approaching the intracellular or extracellular portal and subsequently from being exported by Pdr5p.
authors: Zhejiang University, College of Life Sciences, Hangzhou, China.
authors: Zhigang
authors: Z
authors: Chen
authors: Zhejiang University, College of Life Sciences, Hangzhou, China.
authors: Jingkai
authors: J
authors: Li
authors: Zhejiang University, College of Life Sciences, Hangzhou, China.
authors: Wei
authors: W
authors: Wang
authors: Cornell University, Division of Nutritional Sciences, Ithaca, NY, USA.
authors: Xiaoxian
authors: X
authors: Guo
authors: Zhejiang University, College of Life Sciences, Hangzhou, China.
authors: Yongquan
authors: Y
authors: Li
authors: Zhejiang University, College of Life Sciences, Hangzhou, China.
authors: Xuming
authors: X
authors: Mao
authors: Zhejiang Hospital, Hangzhou, China.
authors: Xinyu
authors: X
authors: Chen
authors: Zhejiang University, College of Life Sciences, Hangzhou, China. Electronic address: guanwj@zju.edu.cn.
authors: Wenjun
authors: W
authors: Guan
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000935:Antifungal Agents / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000494:pharmacology; D001692:Biological Transport; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D003513:Cycloheximide / Q000494:pharmacology; D025141:Drug Resistance, Fungal; D015725:Fluconazole / Q000494:pharmacology; D007166:Immunosuppressive Agents / Q000494:pharmacology; D016297:Mutagenesis, Site-Directed; D009154:Mutation / Q000235:genetics*; D012235:Rhodamines / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016559:Tacrolimus / Q000494:pharmacology
chemical_list: D018528:ATP-Binding Cassette Transporters; D000935:Antifungal Agents; D000970:Antineoplastic Agents; D007166:Immunosuppressive Agents; C092438:PDR5 protein, S cerevisiae; D012235:Rhodamines; D029701:Saccharomyces cerevisiae Proteins; C026188:rhodamine 6G; D015725:Fluconazole; D003513:Cycloheximide; D016559:Tacrolimus
keywords: ATP-binding cassette transporter; ATPase activity; Drug susceptibility; Transmembrane helix; Yeast