Paletzki R F
Laboratory of Systems Neuroscience/NIMH, Bethesda, MD, USA.
Neuroscience. 2002;109(1):15-26. doi: 10.1016/s0306-4522(01)00352-9.
A search for genes differentially expressed in the rat striatum revealed a gene fragment with a ventral to dorsal striatal expression pattern. The sequence of the fragment was used to isolate mouse and rat clones that upon sequencing were identified as homologous to human guanine deaminase. Here we report the distribution of guanine deaminase in the rodent brain. In situ hybridization localization of the encoding mRNA showed a distribution primarily in forebrain areas including cortical pyramidal neurons, ventral striatal medium spiny neurons, hippocampal pyramidal neurons in CA3-CA1 and granule cells in the dentate gyrus, and neurons of the amygdala. Immunohistochemistry using antibodies raised against peptide fragments derived from the guanine deaminase protein sequence showed localization of guanine deaminase in areas predicted by the mRNA distribution. In addition to immunolabeling of neurons in the cerebral cortex, hippocampus, striatum and amygdala there was also labeling in the terminal fields of these neurons including the thalamus, globus pallidum and substantia nigra. A functional histochemical assay that demonstrates the site of guanine deamination shows guanine deaminase activity in a pattern that matched the immunohistochemical localization. The cellular distribution of guanine deaminase to distal areas of the cell including terminals and dendrites was additionally demonstrated by the expression of recombinant guanine deaminase in transformed cortical neurons in culture. In summary we have described the isolation and characterization of mouse and rat guanine deaminase. The expression of guanine deaminase is primarily restricted to forebrain neurons. A histochemical assay was used to localize guanine deaminase activity to the dendrites and axons of neurons expressing guanine deaminase.
对大鼠纹状体中差异表达基因的搜索揭示了一个具有从腹侧到背侧纹状体表达模式的基因片段。该片段的序列用于分离小鼠和大鼠克隆，测序后确定它们与人鸟嘌呤脱氨酶同源。在此，我们报告鸟嘌呤脱氨酶在啮齿动物脑中的分布。编码mRNA的原位杂交定位显示其主要分布在前脑区域，包括皮质锥体细胞、腹侧纹状体中等棘状神经元、CA3 - CA1区的海马锥体细胞、齿状回颗粒细胞以及杏仁核神经元。使用针对源自鸟嘌呤脱氨酶蛋白序列的肽片段产生的抗体进行免疫组织化学分析，显示鸟嘌呤脱氨酶的定位与mRNA分布预测的区域一致。除了在大脑皮层、海马体、纹状体和杏仁核的神经元中进行免疫标记外，在这些神经元的终末区域，包括丘脑、苍白球和黑质也有标记。一种显示鸟嘌呤脱氨位点的功能性组织化学分析表明，鸟嘌呤脱氨酶活性的模式与免疫组织化学定位相匹配。通过在培养的转化皮质神经元中表达重组鸟嘌呤脱氨酶，进一步证明了鸟嘌呤脱氨酶在细胞远端区域（包括终末和树突）的细胞分布。总之，我们描述了小鼠和大鼠鸟嘌呤脱氨酶的分离和特性。鸟嘌呤脱氨酶的表达主要局限于前脑神经元。一种组织化学分析用于将鸟嘌呤脱氨酶活性定位到表达鸟嘌呤脱氨酶的神经元的树突和轴突上。
