The mouse vesicular inhibitory amino acid transporter gene: expression during embryogenesis, analysis of its core promoter in neural stem cells and a reconsideration of its alternate splicing.
The vesicular inhibitory amino acid transporter, VIAAT (also known as vesicular GABA transporter VGAT) transports GABA or glycine into synaptic vesicles. To initiate an analysis of the expression and regulation of VIAAT during neurogenesis we have cloned and characterized the mouse Viaat gene. We find that the mouse Viaat coding sequence is encoded by two exons spanning 5.3 kb. A survey of expression by whole mount in situ hybridization of mouse embryos indicates that Viaat is activated early in neuron differentiation and is expressed widely within the developing CNS; however, we did not detect expression in the superficial non-neural structures that express the GABA synthase Gad1. Analysis of the Viaat promoter indicates that a minimal promoter region containing a CG rich sequence is sufficient for efficient expression in neural stem and precursor cells. Our analysis of the Viaat sequence and splicing does not support the existence of two Viaat isoforms as previously proposed [Ebihara et al., Brain Res. Mol Brain Res. 110 (2003), 126-139]. Instead, the alternative isoform Viaat-a appears to be due to PCR artifacts that have occurred independently in multiple labs.
Oh
Won-Jong
WJ
Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, 30912, USA.
Noggle
Scott A
SA
Maddox
Dennis M
DM
Condie
Brian G
BG
D017398:Alternative Splicing; D026905:Amino Acid Transport Systems / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D045744:Cell Line, Tumor; D018899:CpG Islands / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009420:Nervous System / Q000196:embryology / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics*; D020033:Protein Isoforms / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D013234:Stem Cells / Q000378:metabolism; D014162:Transfection; D050495:Vesicular Inhibitory Amino Acid Transport Proteins
D026905:Amino Acid Transport Systems; D020033:Protein Isoforms; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D050495:Vesicular Inhibitory Amino Acid Transport Proteins; C492244:Viaat protein, mouse; D008156:Luciferases