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Importance of cholesterol in dopamine transporter function
Author(s) -
Jones Kymry T.,
Zhen Juan,
Reith Maarten E. A.
Publication year - 2012
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/jnc.12007
Subject(s) - cholesterol , raft , efflux , chemistry , lipid raft , dopamine transporter , reverse cholesterol transport , biophysics , transporter , biochemistry , biology , lipoprotein , organic chemistry , copolymer , gene , polymer
The conformation and function of the dopamine transporter ( DAT ) can be affected by manipulating membrane cholesterol, yet there is no agreement as to the impact of cholesterol on the activity of lipid‐raft localized DAT s compared with non‐raft DAT s. Given the paucity of information regarding the impact of cholesterol on substrate efflux by the DAT , this study explores its influence on the kinetics of DAT ‐mediated DA efflux induced by dextroamphetamine, as measured by rotating disk electrode voltammetry ( RDEV ). Treatment with methyl‐β‐cyclodextrin (mβ CD ), which effectively depletes total membrane cholesterol––uniformly affecting cholesterol– DAT interactions in both raft and non‐raft membrane domains––reduced both DA uptake and efflux rate. In contrast, disruption of raft‐localized DAT by cholesterol chelation with nystatin had no effect, arguing against a vital role for raft‐localized DAT in substrate uptake or efflux. Supranormal repletion of cholesterol‐depleted cells with the analog desmosterol, a non‐raft promoting sterol, was as effective as cholesterol itself in restoring transport rates. Further studies with Zn 2+ and the conformationally biased W84L DAT mutant supported the idea that cholesterol is important for maintaining the outward‐facing DAT with normal rates of conformational interconversions. Collectively, these results point to a role for direct cholesterol– DAT interactions in regulating DAT function.