Investigation of G72 (DAOA) expression in the human brain
Investigation of G72 (DAOA) expression in the human brain
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DOI：
10.1186/1471-244x-8-94
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发表时间：
2008-12-11
期刊：
影响因子：
4.4
通讯作者：
Maycox, Peter R.
中科院分区：
文献类型：
--
作者：
Benzel, Isabel;Kew, James N. C.;Maycox, Peter R.
背景：十多项独立研究表明，13q 染色体上 G72/G30 基因座的多态性与精神分裂症或躁郁症相关。尽管遗传学研究结果非常可靠，但预测的 G72 蛋白的生理作用迄今为止尚未得到解决。最初的报告表明 G72 是 D-氨基酸氧化酶 (DAO) 的激活剂，支持精神分裂症的谷氨酸功能障碍假说。然而，这些发现随后没有被重现，并且内源性人 G72 mRNA 和蛋白质表达的报道极其有限。为了更好地了解这一假定的精神分裂症易感基因的功能，我们试图证明G72 mRNA和蛋白在人脑相关区域的表达。方法：通过Northern blotting、半定量SYBR-Green和Taqman RT-PCR研究G72 mRNA的表达。使用两种定制的特异性抗 G72 肽抗体通过蛋白质印迹研究人体组织裂解物中的蛋白质表达。对 G72/G30 基因座进行了深入的计算机分析，以尝试识别基序或调控元件，从而深入了解 G72 mRNA 表达和转录稳定性。结果：尽管使用了高度灵敏的技术，但我们未能在各种人体组织（例如成人大脑、杏仁核、尾状核、胎儿大脑、脊髓和睾丸）、人类细胞系或精神分裂症/对照柱中鉴定出 G72 mRNA 的显着水平。尸检 BA10 样品。此外，利用蛋白质印迹法结合灵敏的检测方法，我们也无法检测到人脑多个区域（包括小脑和杏仁核）、脊髓或睾丸中的G72蛋白。详细的计算机分析提供了多条证据，支持 G72 表达明显低或缺失。结论：我们的结果表明，天然 G72 蛋白通常不存在于我们在本研究中分析的组织中。我们还得出结论，相关大脑区域缺乏明显的 G72 表达并不支持 G72 通过 DAO 介导的机制调节 DAO 活性和精神分裂症病理学的作用。计算机分析表明 G72 表达不强，并且转录本可能不稳定。需要进一步的研究来了解 G72/30 基因座对精神分裂症的重要性。
Background: Polymorphisms at the G72/G30 locus on chromosome 13q have been associated with schizophrenia or bipolar disorder in more than ten independent studies. Even though the genetic findings are very robust, the physiological role of the predicted G72 protein has thus far not been resolved. Initial reports suggested G72 as an activator of D-amino acid oxidase (DAO), supporting the glutamate dysfunction hypothesis of schizophrenia. However, these findings have subsequently not been reproduced and reports of endogenous human G72 mRNA and protein expression are extremely limited. In order to better understand the function of this putative schizophrenia susceptibility gene, we attempted to demonstrate G72 mRNA and protein expression in relevant human brain regions.Methods: The expression of G72 mRNA was studied by northern blotting and semi-quantitative SYBR-Green and Taqman RT-PCR. Protein expression in human tissue lysates was investigated by western blotting using two custom-made specific anti-G72 peptide antibodies. An in-depth in silico analysis of the G72/G30 locus was performed in order to try and identify motifs or regulatory elements that provide insight to G72 mRNA expression and transcript stability.Results: Despite using highly sensitive techniques, we failed to identify significant levels of G72 mRNA in a variety of human tissues (e. g. adult brain, amygdala, caudate nucleus, fetal brain, spinal cord and testis) human cell lines or schizophrenia/control post mortem BA10 samples. Furthermore, using western blotting in combination with sensitive detection methods, we were also unable to detect G72 protein in a number of human brain regions (including cerebellum and amygdala), spinal cord or testis. A detailed in silico analysis provides several lines of evidence that support the apparent low or absent expression of G72.Conclusion: Our results suggest that native G72 protein is not normally present in the tissues that we analysed in this study. We also conclude that the lack of demonstrable G72 expression in relevant brain regions does not support a role for G72 in modulation of DAO activity and the pathology of schizophrenia via a DAO-mediated mechanism. In silico analysis suggests that G72 is not robustly expressed and that the transcript is potentially labile. Further studies are required to understand the significance of the G72/30 locus to schizophrenia.