RT Journal Article
SR Electronic
T1 Membrane cholesterol regulates inhibition and substrate transport by the glycine transporter, GlyT2
JF Life Science Alliance
JO Life Sci. Alliance
FD Life Science Alliance LLC
SP e202201708
DO 10.26508/lsa.202201708
VO 6
IS 4
A1 Frangos, Zachary J
A1 Wilson, Katie A
A1 Aitken, Heather M
A1 Cantwell Chater, Ryan
A1 Vandenberg, Robert J
A1 O’Mara, Megan L
YR 2023
UL https://www.life-science-alliance.org/content/6/4/e202201708.abstract
AB Membrane cholesterol binds to and modulates the function of various SLC6 neurotransmitter transporters, including stabilizing the outward-facing conformation of the dopamine and serotonin transporters. Here, we investigate how cholesterol binds to GlyT2 (SLC6A5), modulates glycine transport rate, and influences bioactive lipid inhibition of GlyT2. Bioactive lipid inhibitors are analgesics that bind to an allosteric site accessible from the extracellular solution when GlyT2 adopts an outward-facing conformation. Using molecular dynamics simulations, mutagenesis, and cholesterol depletion experiments, we show that bioactive lipid inhibition of glycine transport is modulated by the recruitment of membrane cholesterol to a binding site formed by transmembrane helices 1, 5, and 7. Recruitment involves cholesterol flipping from its membrane orientation, and insertion of the 3′ hydroxyl group into the cholesterol binding cavity, close to the allosteric site. The synergy between cholesterol and allosteric inhibitors provides a novel mechanism of inhibition and a potential avenue for the development of potent GlyT2 inhibitors as alternative therapeutics for the treatment of neuropathic pain and therapeutics that target other SLC6 transporters.