Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
Cancer Biology Program, St. Jude Pediatric Comprehensive Cancer Center, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
J Cell Sci. 2019 Feb 20;132(5):jcs222984. doi: 10.1242/jcs.222984.
Classically, canonical autophagy has been considered a survival mechanism initiated in response to nutrient insufficiency. We now understand that autophagy functions in multiple scenarios where it is necessary to maintain homeostasis. Recent evidence has established that a variety of non-canonical functions for autophagy proteins are mechanistically and functionally distinct from autophagy. LC3-associated phagocytosis (LAP) is one such novel function for autophagy proteins and is a contributor to immune regulation and inflammatory responses across various cell and tissue types. Characterized by the conjugation of LC3 family proteins to phagosome membranes, LAP uses a portion of the canonical autophagy machinery, following ligation of surface receptors that recognize a variety of cargos including pathogens, dying cells, soluble ligands and protein aggregates. However, instead of affecting canonical autophagy, manipulation of the LAP pathway alters immune activation and inflammatory responses. In this Cell Science at a Glance article and the accompanying poster, we detail the divergence of this distinctive mechanism from that of canonical autophagy by comparing and contrasting shared and unique components of each pathway.
经典观点认为,自噬是细胞在营养不足时为了生存而启动的一种机制。而现在我们知道,自噬在许多维持细胞内环境稳定的情况下都发挥着作用。最近的研究证据表明,自噬蛋白的多种非经典功能在机制和功能上都有别于自噬。LC3 相关的噬作用(LC3-associated phagocytosis,LAP)就是自噬蛋白的一种新功能,它参与了各种细胞和组织类型的免疫调节和炎症反应。LAP 的特征是 LC3 家族蛋白与吞噬体膜的连接,它利用了一部分经典自噬机制,在识别包括病原体、死亡细胞、可溶性配体和蛋白聚集体等多种货物的表面受体被配体结合后,就会启动该机制。然而,与影响经典自噬的机制不同,LAP 途径的调控会改变免疫激活和炎症反应。在本期《细胞科学精粹》文章及其配套海报中,我们通过比较和对比每条通路的共享和独特成分,详细描述了这一独特机制与经典自噬的差异。