Creatine transporter (CRT, SLC6A8) is a member of the superfamily of Na⁺/Cl^--coupled transporters for neurotransmitters and organic osmolytes. Creatine Transporter is responsible transports creatine to the blood-brain barrier and into neurons of the central nervous system (CNS). It plays an important role in the storage and utilization of cellular phosphate-bound energy mediated by creatine kinase. It is essential for maintaining brain creatine levels and central nervous system (CNS) functions^1,2.

Creatine transporter is expressed in various tissues including brain, retina, skeletal muscle, and heart¹. The transporter structure contains 12 membrane-spanning domains, a large extracellular loop containing sites for N-linked glycosylation between the third and fourth transmembrane domains. The amino- and carboxyl-termini of the transporter are intracellular³.

Creatine transporter is encoded by the SLC6A8 gene and loss-of-function mutations result in creatine deficiency resulting in cerebral creatine deficiency syndromes (CCDSs). These syndromes are the second-most common cause of chromosome X-linked mental retardation. Creatine concentration in the brain is greatly reduced in these patients and they show various neurodevelopmental disorders, including delays in speech and language development, seizures, mental retardation, autism and epilepsy¹.