Murray Peter J
Department of Infectious Diseases, St. Jude Children's Research Hospital, 332 North Lauderdale, Memphis, TN 38105, USA.
Curr Opin Immunol. 2005 Aug;17(4):352-8. doi: 10.1016/j.coi.2005.05.006.
NOD1 and NOD2 are members of a diverse family of cytoplasmic proteins that contain C-terminal leucine-rich repeats. Because of their similarity to a family of plant proteins involved in pathogen resistance, and because mutations in Card15, encoding NOD2, are frequently found in familial cases of Crohn's disease--an intestinal malady of excessive inflammation--NOD proteins have been proposed to fulfill a role in the intracellular sensing of bacteria. Indeed, NOD proteins seem to alter the ability of cells to respond to fragments from bacterial cell walls. This system could function analogously to the Toll-like receptors--extracellular proteins that play an essential role in pathogen recognition. However, the idea of an intracellular system that specifically recognizes bacterial cell components is controversial and alternative functions of NODs are possible including regulating signal transduction systems.
NOD1和NOD2是一类多样的细胞质蛋白家族成员，这些蛋白含有C端富含亮氨酸的重复序列。由于它们与参与病原体抗性的一类植物蛋白相似，并且由于编码NOD2的Card15突变在克罗恩病（一种肠道过度炎症性疾病）的家族病例中经常被发现，因此有人提出NOD蛋白在细胞内感知细菌方面发挥作用。事实上，NOD蛋白似乎改变了细胞对细菌细胞壁片段作出反应的能力。该系统的功能可能类似于Toll样受体——在病原体识别中起重要作用的细胞外蛋白。然而，专门识别细菌细胞成分的细胞内系统这一观点存在争议，NODs的其他功能也是可能的，包括调节信号转导系统。
