Proton-linked monocarboxylate transporter that mediates creatine transport across the plasma membrane. Interacts with isoform 2 of BSG. Detected in kidney, choroid plexus, testis, lung, stomach, large and small intestine, spleen, fat and parotid gland (PubMed:21778275). In eye, expressed in cornea, ciliary epithelium, lens epithelium and lens fiber (PubMed:21778275). Homozygous knockout rats are born to expected Mendelian ratios and no obvious ocular phenotype is observed. Belongs to the major facilitator superfamily. Monocarboxylate porter (TC 2.A.1.13) family.