IPAF is activated

Although a direct interaction between IPAF and an activating ligand has not been demonstrated, IPAF can be activated by cytosolic flagellin either applied experimentally or resulting from the activity of the virulence-associated type III or V secretion systems (Franchi et al. 2006, Miao et al 2007, 2008). Activation can also be flagellin-independent (Suzuki et al. 2007, Sutterwala et al. 2007), suggesting alternative mechanisms that are likely to involve recognition of components of the bacterial type III secretion system (Miao et al. 2010). The LRR domain of IPAF appears to repress activity in the absence of a ligand as removal of this domain leads to constitutive activation (Poyet et al. 2001).

尽管尚未证实IPAF与激活配体之间的直接相互作用，但IPAF可通过胞质鞭毛蛋白的激活实现，该激活既可以是实验性应用的结果，也可以是毒力相关III型或V型分泌系统活动所致（Franchi等，2006；Miao等，2007，2008）。此外，激活亦可能独立于鞭毛蛋白（Suzuki等，2007；Sutterwala等，2007），这暗示了可能涉及细菌III型分泌系统成分识别的替代机制（Miao等，2010）。IPAF的LRR结构域似乎在无配体存在时抑制活性，因为去除此结构域会导致恒定激活（Poyet等，2001）。