Distinct Protein Forms Are Produced From Alternatively Spliced Bicistronic Glutamic Acid Decarboxylase mRNAs During Development

摘要: It has been shown that the enzyme glutamic acid decarboxylase (GAD; EC 4.1.1.15), which catalyzes conversion of L-glutamate to gamma-aminobutyric in central nervous system vertebrates, can be first detected rodents at late embryonic stages. In contrast, we have found gene coding for 67-kDa form GAD is already transcriptionally active day E10.5 mouse. addition 3.5-kb adult-type mRNA, two 2-kb messages contain alternatively spliced exons 80 (I-80) and 86 (I-86) bp, respectively. The overlapping stop-start codon TGATG, exons, converts monocistronic transcript into a bicistronic one, 25-kDa leader peptide 44-kDa enzymatically truncated GAD. A second stop 3' end 86-bp exon abolishes expression products mRNAs were identified rabbit reticulocyte vitro translation system, COS cells, mouse embryos. forms represent distinct functional domains display characteristic developmental patterns, consistent with possible role formation acid-ergic inhibitory synapses.