Utilization of an intron located polyadenlyation site resulted in four novel glutamate decarboxylase transcripts.
Glutamate decarboxylase (GAD) is the rate-limiting enzyme in the synthesis of gamma-aminobutyric acid (GABA), the most important inhibitory neurotransmitter in central nervous system (CNS). Two homologous forms of GAD encoded by separate genes have been identified in mammalian brain, with molecular weight of 65 kDa (GAD65) and 67 kDa (GAD67). In the present study, four novel GAD67 transcripts produced by alternative splicing and polyadenlyation were cloned from rat testis. These novel GAD67 transcripts were widely expressed in non-neuronal tissues. During rat testis maturation, their expression level showed a time dependent change. These transcripts were predicted to synthesis of GAD proteins truncated of the binding site for pyridoxal phosphate, an essential cofactor, therefore cannot function as a decarboxylase. Thus, post-transcriptional processing mechanism as alternative splicing and polyadenlyation may play a crucial role in regulating rat GAD67 gene expression.
Liu
Haixiong
H
Shanghai Key Laboratory for Molecular Andrology, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Yue Yang Road, Shanghai, 200031, China.
Wang
Zhiqiang
Z
Li
Shifeng
S
Zhang
Yunbin
Y
Yan
Yuan-Chang
YC
Li
Yi-ping
YP