On the energy-dependence of Hoechst 33342 transport by the ABC transporter LmrA
| dc.contributor.author | Venter, H. | |
| dc.contributor.author | Velamakanni, S. | |
| dc.contributor.author | Balakrishnan, L. | |
| dc.contributor.author | Van, V.H.W. | |
| dc.date.issued | 2008 | |
| dc.description.abstract | LmrA is an ATP-binding cassette (ABC) multidrug transporter from Lactococcus lactis, and is a structural homologue of the human multidrug resistance P-glycoprotein (ABCB1), the overexpressionof which is associated withmultidrug resistance intumours.We recently observed that a truncated version of LmrA lacking the nucleotide-binding domain mediates a proton motive force-dependent ethidiumtransport reaction by catalyzing proton-ethidiumsymport. This finding raised the questionwhether protonmotive force-dependent transport can also be observed for other drugs, and whether this reaction is also relevant for full-length LmrA. Furthermore, the observations on LmrA-MD raised the question whether ATP-dependent transport by LmrA in intact cells could be due to the activity of independent ABC transporters that might become upregulated in the lactococcal cells due to the overexpression of LmrA; the recently identified ABCmultidrug transporterLmrCDwasput forward as a possible candidate. Here, we investigated the energy coupling to the transport of the amphiphilic dye Hoechst 33342 in proteoliposomescontainingpurifiedLmrA. For this purpose,LmrAwasobtainedfrom lactococcal cells lacking the genomic lmrA and lmrCD genes, in which LmrA was expressed froma plasmid. To separate ATP-dependence fromprotonmotive force-dependence, we also used mutant LmrA proteins, which were affected in their ability to hydrolyseATP.Our studies in proteoliposomes demonstrate that LmrA can catalyze Hoechst 33342 transport independent of auxiliary proteins, in an ATP-dependent fashion and a transmembrane chemical proton gradient (interior acidic)-dependent fashion. | |
| dc.identifier.citation | Biochemical Pharmacology, 2008; 75(4):866-874 | |
| dc.identifier.doi | 10.1016/j.bcp.2007.10.022 | |
| dc.identifier.issn | 0006-2952 | |
| dc.identifier.issn | 1873-2968 | |
| dc.identifier.uri | https://hdl.handle.net/1959.8/155984 | |
| dc.language.iso | en | |
| dc.publisher | Elsevier | |
| dc.rights | Copyright 2007 Elsevier | |
| dc.source.uri | https://doi.org/10.1016/j.bcp.2007.10.022 | |
| dc.subject | ABC transporter | |
| dc.subject | energy-coupling | |
| dc.subject | Hoechst 33342 transport | |
| dc.subject | LmrA | |
| dc.subject | proteoliposomes | |
| dc.subject | nucleotide-binding domain mutants | |
| dc.title | On the energy-dependence of Hoechst 33342 transport by the ABC transporter LmrA | |
| dc.type | Journal article | |
| pubs.publication-status | Published | |
| ror.mmsid | 9915911029601831 |