Holler T, Berse B, Cermak J M, Diebler M F, Blusztajn J K
Department of Pathology, Boston University School of Medicine, MA 02118, USA.
Neurosci Lett. 1996 Jul 12;212(2):107-10. doi: 10.1016/0304-3940(96)12808-1.
The neurotransmitter acetylcholine (ACh) is synthesized by the enzyme choline acetyltransferase (ChAT) and then transported into synaptic vesicles by the vesicular acetylcholine transporter (VAChT). Since the VAChT gene is located within the first intron of the ChAT gene, it is likely that expression of the two genes is coregulated. We compared the developmental expression of VAChT and ChAT mRNA and protein in rat brain. ChAT mRNA and enzyme activity increased by almost 10-fold from embryonic day 19 to adulthood, with the most pronounced increase occurring after birth. In contrast, VAChT mRNA increased by only about 2-fold from late embryonic stages to adult levels. However, VAChT protein followed the developmental pattern of ChAT activity, revealing a large excess of VAChT mRNA over VAChT protein during early stages of development. The results are suggestive of differential mechanisms of ChAT and VAChT regulation during brain development, and of possible translational control of VAChT expression.
神经递质乙酰胆碱（ACh）由胆碱乙酰转移酶（ChAT）合成，然后通过囊泡乙酰胆碱转运体（VAChT）转运至突触小泡。由于VAChT基因位于ChAT基因的第一个内含子内，这两个基因的表达很可能受到共同调控。我们比较了大鼠脑中VAChT和ChAT mRNA及蛋白质的发育表达情况。从胚胎第19天到成年期，ChAT mRNA和酶活性增加了近10倍，出生后增加最为显著。相比之下，从胚胎后期到成年期，VAChT mRNA仅增加了约2倍。然而，VAChT蛋白遵循ChAT活性的发育模式，这表明在发育早期VAChT mRNA的量大大超过VAChT蛋白。这些结果提示了在脑发育过程中ChAT和VAChT调控机制的差异，以及VAChT表达可能存在的翻译控制。
