Glutamate Dehydrogenase 2 (GLUD2)

Glutamate dehydrogenase catalyzes the reversible oxidative deamination of glutamate to alpha-ketoglutarate using NAD and/or NADP as cofactors. A novel cDNA encoded by an X-linked intronless gene was cloned. Reverse transcription-polymerase chain reaction analysis of human tissues demonstrated that the novel cDNA is expressed in human retina, testis, and, at a lower level, brain. In vitro translation of mRNAs derived from GLUD1 and the new gene, called GLUD2, generated proteins with distinct electrophoretic characteristics. The retinal cDNA was expressed in the baculovirus heterologous system, producing a protein capable of catalyzing the oxidative deamination of glutamate. Expression of the GLUD2 gene in human retina was of particular interest in view of the finding that glutamate is an important retinal excitatory transmitter.