Probable retinal pigment epithelium (RPE)-specific proton-coupled L-lactate transporter (By similarity). May facilitate transport of lactate and H(+) out of the retina and could therefore play a role in pH and ion homeostasis of the outer retina (By similarity). (S)-lactate(in) + H(+)(in) = (S)-lactate(out) + H(+)(out) Basolateral sorting signals (BLSS) in C-terminal cytoplasmic tail ensure its basolateral expression (PubMed:21199217). Colocalizes with BSG in basolateral cell membrane of the retinal pigment epithelium (By similarity). Retinal pigment epithelium. The two basolateral sorting signals (BSS) are required to direct SLC16A8 to the basolateral membrane. Belongs to the major facilitator superfamily. Monocarboxylate porter (TC 2.A.1.13) family.