Sodium- and chloride-dependent glycine transporter (PubMed:1534013, PubMed:16181645). Essential for regulating glycine concentrations at inhibitory glycinergic synapses (By similarity). chloride(out) + glycine(out) + 2 Na(+)(out) = chloride(in) + glycine(in) + 2 Na(+)(in) Inhibited by sarcosine. Interacts with EXOC1; interaction increases the transporter capacity of SLC6A9 probably by promoting its insertion into the cell membrane (PubMed:16181645). Interacts with EXOC3 and EXOC4 (PubMed:16181645). Found only in the white matter of the CNS. Found in the gray matter of CNS as well as in macrophages and mast cells in peripheral tissues. Belongs to the sodium:neurotransmitter symporter (SNF) (TC 2.A.22) family. SLC6A9 subfamily.