SLC16A1 Gene - Monocarboxylate Transporter 1 (MCT1) | Function, Mutations & Diseases

SLC16A1 (Solute Carrier Family 16 Member 1) encodes the monocarboxylate transporter 1 (MCT1), a proton-coupled transporter that mediates the bidirectional movement of monocarboxylates such as lactate, pyruvate, and ketone bodies across the plasma membrane. MCT1 is essential for cellular energy metabolism, particularly in tissues with high glycolytic flux (e.g., skeletal muscle, erythrocytes, and tumors). The gene is located on chromosome 1p13.2 and is widely expressed. Mutations in SLC16A1 are associated with erythrocyte lactate transporter defect (also known as symptomatic deficiency of lactate transport in erythrocytes) and have been implicated in cancer metabolism and exercise intolerance.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Monocarboxylate transport (Reactome: R-HSA-433692)

• Gluconeogenesis (Reactome: R-HSA-70263)

• Glycolysis (Reactome: R-HSA-70171)

• Metabolism of carbohydrates (Reactome: R-HSA-71387)

MCT1 (UniProt P53985) is a 500-amino acid transmembrane protein with 12 predicted alpha-helical domains. It functions as a proton-coupled symporter for lactate, pyruvate, and ketone bodies. The protein requires association with basigin (CD147) for proper plasma membrane localization and activity. MCT1 is expressed in nearly all tissues, with highest levels in skeletal muscle, heart, and erythrocytes. It plays a critical role in the Cori cycle, shuttling lactate from glycolytic tissues to the liver for gluconeogenesis. In cancer, MCT1 overexpression supports the Warburg effect by exporting lactate from tumor cells, making it a therapeutic target.