A single report has described a putative urate transporter (UAT) which was reported to catalyze the electrogenic efflux of urate from mammalian cells following degradation of the purine bases, adenine and guanine, to uric acid. A cDN A was isolated which encodes a protein of 322 amino acids. It is largely hydrophilic and is homologous to a family of galactose binding lectins, the galectins. The selective urate transport activity of the recombinant UAT was reconstituted in planar lipid bilayers. The protein possibly exhibits a single transmembrane α-helical spanner (TMS). In view of its dubious topology, assignment of the transport function to this protein must be considered tentative.

The proposed transport reaction catalyzed by UAT is:

urate (in) urate (out)