GC2, also known as Slc25a18, is a mitochondrial glutamate transporter. Mitochondrial glutamate transporters catalyze the entry of glutamate into the mitochondrial matrix, either with protons or in exchange for hydroxyl ions, playing an important role in amino acid degradation, nitrogen metabolism, and urea synthesis. Two isoforms have been identified, GC1 (Slc25a22) and GC2. Gene expression analyses revealed that GC1 is expressed at higher levels than GC2 in the heart, kidney, lung, small intestine, and spleen, whereas both are equally expressed in the brain. GC2 is primarily expressed in the brain, with lower expression in the testis, and minimal expression in other tissues (1).
GC2 has been identified through the analysis of RNA sequences from half a million single brain cells as a highly expressed gene and a potential marker for fibrous astrocytes in non-telencephalon brain regions (2).