Department of Biochemistry and Molecular Biology, University of Athens, Panepistimiopolis, Zografou, 15701, Athens, Greece.
Mol Biol Rep. 2011 Feb;38(2):1005-11. doi: 10.1007/s11033-010-0196-x. Epub 2010 Jun 11.
L-Dopa decarboxylase (DDC) catalyses the decarboxylation of L-Dopa. It has been shown that the DDC gene undergoes alternative splicing within its 5'-untranslated region (UTR), in a tissue-specific manner, generating identical protein products. The employment of two alternative 5'UTRs is thought to be responsible for tissue-specific expression of the human DDC mRNA. In this study, we focused on the investigation of the nature of the mRNA expression in human cell lines of neural and non-neural origin. Our results show the expression of a neural-type DDC mRNA splice variant, lacking exon 3 in all cell lines studied. Co-expression of the full length non-neural DDC mRNA and the neural-type DDC splice variant lacking exon 3 was detected in all cell lines. The alternative DDC protein isoform, Alt-DDC, was detected in SH-SY5Y and HeLa cells. Our findings suggest that the human DDC gene undergoes complex processing, leading to the formation of multiple mRNA isoforms. The study of the significance of this phenomenon of multiple DDC mRNA isoforms could provide us with new information leading to the elucidation of the complex biological pathways that the human enzyme is involved in.
L-多巴脱羧酶（DDC）催化 L-多巴的脱羧反应。已经表明，DDC 基因在其 5'-非翻译区（UTR）内以组织特异性的方式进行选择性剪接，产生相同的蛋白质产物。两种选择性 5'UTR 的使用被认为是负责人类 DDC mRNA 的组织特异性表达。在这项研究中，我们专注于研究神经和非神经来源的人类细胞系中 mRNA 表达的性质。我们的结果表明，在所有研究的细胞系中都表达了一种缺少外显子 3 的神经型 DDC mRNA 剪接变体。在所有细胞系中都检测到全长非神经 DDC mRNA 和缺少外显子 3 的神经型 DDC 剪接变体的共表达。替代性 DDC 蛋白同工型 Alt-DDC 被检测到在 SH-SY5Y 和 HeLa 细胞中。我们的发现表明，人类 DDC 基因经历了复杂的加工，导致形成多种 mRNA 同工型。研究这种多 DDC mRNA 同工型的意义可能为我们提供新的信息，有助于阐明人类酶所涉及的复杂生物学途径。
