The State Key Laboratory of Pharmaceutical Biotechnology, College of Life Science and School of Stomatology, Affiliated Stomatological Hospital, Nanjing University, Nanjing, PR China.
Proteomics. 2013 Aug;13(16):2398-413. doi: 10.1002/pmic.201300017. Epub 2013 Jul 11.
Fas-associated death domain-containing protein (FADD) is a classical apoptotic pathway adaptor. Further studies revealed that it also plays essential roles in nonapoptotic processes, which is assumed to be regulated by its phosphorylation. However, the exact mechanisms are still poorly understood. To study the nonapoptotic effects of FADD, a comprehensive strategy of proteomics identification combined with bioinformatic analysis was undertaken to identify proteins differentially expressed in three cell lines containing FADD and its mutant, FADD-A and FADD-D. The cell lines were thought to bear wild-type FADD, unphosphorylated FADD mimic and constitutive phosphorylated FADD mimic, respectively. A total of 47 proteins were identified to be significantly changed due to FADD phosphorylation. Network analysis using MetaCore™ identified a number of changed proteins that were involved in cellular metabolic process, including lipid metabolism, fatty acid metabolism, glycolysis, and oxidative phosphorylation. The finding that FADD-D cell line showed an increase in fatty acid oxidation argues that it could contribute to the leaner phenotype of FADD-D mice as reported previously. In addition, six proteins related to the ubiquitin-proteasome pathway were also specifically overexpressed in FADD-D cell line. Finally, the c-Myc gene represents a convergent hub lying at the center of dysregulated pathways, and was upregulated in FADD-D cells. Taken together, these studies allowed us to conclude that impaired mitochondrial function and proteolysis might play pivotal roles in the dysfunction associated with FADD phosphorylation-induced disorders.
Fas 相关死亡结构域蛋白（FADD）是一种经典的凋亡途径衔接蛋白。进一步的研究表明，它在非凋亡过程中也发挥着重要作用，这被认为是通过其磷酸化来调节的。然而，确切的机制仍知之甚少。为了研究 FADD 的非凋亡作用，采用蛋白质组学鉴定的综合策略，并结合生物信息学分析，鉴定了三种含有 FADD 及其突变体 FADD-A 和 FADD-D 的细胞系中差异表达的蛋白质。这三种细胞系分别被认为含有野生型 FADD、无磷酸化的 FADD 模拟物和组成型磷酸化的 FADD 模拟物。由于 FADD 磷酸化，共鉴定出 47 种表达显著变化的蛋白质。使用 MetaCore™进行的网络分析确定了许多发生变化的蛋白质，这些蛋白质参与细胞代谢过程，包括脂质代谢、脂肪酸代谢、糖酵解和氧化磷酸化。FADD-D 细胞系中脂肪酸氧化增加的发现表明，它可能有助于先前报道的 FADD-D 小鼠的消瘦表型。此外，FADD-D 细胞系中还特异性地上调了与泛素蛋白酶体途径相关的六种蛋白质。最后，c-Myc 基因代表了一个失调途径的集中枢纽，在 FADD-D 细胞中上调。总之，这些研究使我们得出结论，线粒体功能和蛋白水解的受损可能在与 FADD 磷酸化诱导的疾病相关的功能障碍中发挥关键作用。
