Birth and adaptive evolution of a hominoid gene that supports high neurotransmitter flux.
The enzyme glutamate dehydrogenase (GDH) is important for recycling the chief excitatory neurotransmitter, glutamate, during neurotransmission. Human GDH exists in housekeeping and brain-specific isotypes encoded by the genes GLUD1 and GLUD2, respectively. Here we show that GLUD2 originated by retroposition from GLUD1 in the hominoid ancestor less than 23 million years ago. The amino acid changes responsible for the unique brain-specific properties of the enzyme derived from GLUD2 occurred during a period of positive selection after the duplication event.
Burki
Fabien
F
Center for Integrative Genomics, University of Lausanne, BEP, 1015 Lausanne, Switzerland.
Kaessmann
Henrik
H
D000818:Animals; D001921:Brain / Q000201:enzymology; D019143:Evolution, Molecular; D020440:Gene Duplication; D005969:Glutamate Dehydrogenase / Q000235:genetics* / Q000378:metabolism*; D015186:Hominidae / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D018377:Neurotransmitter Agents / Q000378:metabolism*; D010802:Phylogeny; D018626:Retroelements; D012641:Selection, Genetic; D013997:Time Factors
D007527:Isoenzymes; D018377:Neurotransmitter Agents; D018626:Retroelements; D005969:Glutamate Dehydrogenase