Figure 5.

Substrate and inhibitor specificity of BasC transport activity. (A) BasC substrate specificity. 10 µM [³H]L-serine (1 µCi/µl) influx into BasC-GFP-PLs containing 4 mM of the indicated individual amino acids (black bars). Transport was expressed as the percentage of the transport in BasC-PLs containing 4 mM L-alanine. 10 µM [³H]L-serine (1 µCi/µl) influx into BasC-GFP-PLs measured in the presence of 5 mM of the indicated amino acids in the external medium (white bars). Inhibition was expressed as the percentage of the transport in BasC-GFP-PLs containing 4 mM L-alanine with no cis-inhibitors. Data are from three experiments with three replicates per condition. (B) BasC stereoselectivity. 10 µM [³H]L-serine (1 µCi/µl) influx into BasC-PLs containing 4 mM of the indicated individual L– or D–amino acids (black bars). Transport was expressed as the percentage of the transport in BasC-GFP-PLs containing 4 mM L-alanine. 10 µM [³H]L-serine (1 µCi/µl) influx into BasC-GFP-PLs measured in the presence of 4 mM of the indicated L– or D–amino acids in the external medium (white bars). Inhibition was expressed as the percentage of transport in BasC-GFP-PLs containing 4 mM L-alanine with no cis-inhibitors. Data are from three experiments with three replicates per condition. (C) BasC amino acid derivative specificity. 10 µM [³H]L-serine (1 µCi/µl) influx into BasC-GFP-PLs containing 4 mM of the indicated individual amino acid derivatives (black bars). Transport was expressed as the percentage of transport in BasC-GFP-PLs containing 4 mM L-alanine. 10 µM [³H]L-serine (1 µCi/µl) influx into BasC-GFP-PLs measured in the presence of 4 mM of the indicated amino acid derivatives in the external medium (white bars). Inhibition was expressed as the percentage of transport in BasC-GFP-PLs containing 4 mM L-alanine with no cis-inhibitors. Data are from three experiments with three replicates per condition.