Enables glycine transmembrane transporter activity and thyroid hormone transmembrane transporter activity. Involved in amino acid transport and thyroid hormone transport. Acts upstream of or within L-amino acid transport. Located in apical plasma membrane. Is expressed in several structures, including alimentary system; central nervous system; eye; genitourinary system; and immune system. Used to study sensorineural hearing loss. Orthologous to human SLC7A8 (solute carrier family 7 member 8). [provided by Alliance of Genome Resources, Apr 2022]