Longevity & AgingCryo-EM Reveals How the Taurine Transporter Works and Dimerizes via Cholesterol
Researchers used cryo-EM to solve the first high-resolution structures of the human taurine transporter (TauT) in multiple states: an apo inward-facing open form and substrate-bound occluded forms with taurine or GABA. The structures reveal precisely how TauT recognizes taurine versus GABA, explaining its distinct substrate specificity compared to related GABA transporters. Unexpectedly, when reconstituted in lipid nanodiscs, TauT was also captured as a homodimer stabilized by two cholesterol molecules acting as molecular glue between protomers, alongside direct TM5-TM5 contacts. These findings clarify the molecular basis of taurine transport and open new avenues for treating taurine-deficiency disorders including retinal degeneration, cardiomyopathy, and aging-related conditions.
