Journal article

The loop between helix 4 and helix 5 in the monocarboxylate transporter MCT1 is important for substrate selection and protein stability

S Galic, HP Schneider, A Broer, JW Deitmer, S Broer

BIOCHEMICAL JOURNAL | PORTLAND PRESS LTD | Published : 2003

Abstract

Transport of lactate, pyruvate and the ketone bodies acetoacetate and beta-hydroxybutyrate, is mediated in most mammalian cells by members of the monocarboxylate transporter family (SLC16). A conserved signature sequence has been identified in this family, which is located in the loop between helix 4 and helix 5 and extends into helix 5. We have mutated residues in this signature sequence in the rat monocarboxylate transporter (MCT1) to elucidate the significance of this region for monocarboxylate transport. Mutation of R143 and G153 resulted in complete inactivation of the transporter. For the MCT1(G153V) mutant this was explained by a failure to reach the plasma membrane. The lack of trans..

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