l-Dopa Decarboxylase (DDC) is a pyridoxal requiring enzyme that catalyzes the decarboxylation of L-3,4-dihydroxyphenylalanine (l-Dopa) to Dopamine (DA). The function of DDC in physiological and pathological biochemical pathways remains poorly understood, while the function and regulation of human DDC isoforms is almost completely elusive. We have shown that Annexin V, a fundamental apoptosis marker, is an inhibitor of l-Dopa decarboxylase activity. Here we show the interaction of both the full-length DDC and the truncated isoform alternative DDC (Alt-DDC) with Annexin V in human tissue and cell lines. Interestingly, DDC isoform expression is enhanced or remains unaffected following staurosporine (STS) treatment, despite increased levels of cytotoxicity and apoptosis. The findings presented here provide novel insights concerning the involvement of DDC in programmed cell death.

1- Dopa脱羧酶（DDC）是一种需要吡ido醛的酶，可催化L-3,4-二羟基苯丙氨酸（1 - Dopa）脱羧成多巴胺（DA）。DDC在生理和病理生化途径中的功能仍然知之甚少，而人类DDC同工型的功能和调节几乎完全难以捉摸。我们已经表明，膜联蛋白V（一种基本的细胞凋亡标记）是l的抑制剂-多巴脱羧酶活性。在这里，我们显示了全长DDC和截短的同工型替代DDC（Alt-DDC）与膜联蛋白V在人体组织和细胞系中的相互作用。有趣的是，尽管细胞毒性和细胞凋亡水平增加，但星形孢菌素（STS）处理后DDC亚型的表达仍增强或保持不受影响。这里介绍的发现提供了有关DDC参与程序性细胞死亡的新颖见解。