2.2.1 RIPK1
RIPKs are a seven-member family with the common characteristic of a homologous serine-threonine kinase domain. The family includes RIPK1-RIPK7. RIPK1 was first identified by Stranger et al. in 1995 as a death domain (DD)-including protein coactions with the DD of the Fas receptor, which is capable of inducing apoptosis (Stanger et al. 1995). RIPK1 include an amino-terminal kinase domain, a carboxy-terminal DD and a bridging intermediate domain (ID) that contains a RIP homotypic interaction motif (RHIM) (He and Wang 2018). RIPK1 can connect with several innate immune receptors containing tumor necrosis factor receptors (TNFRs), interferon alpha/beta receptor 1 (IFNAR1), toll-like receptors (TLRs), stimulator of interferon genes protein, mitochondrial antiviral-signaling protein and others to exert important value in innate immune regulation (Vanden Berghe, Hassannia and Vandenabeele 2016). RIPK1 has related to multiple signal reaction containing transcription and translation of inflammatory genes (Najjar et al. 2016, Muendlein et al. 2020), apoptosis, necroptosis and pyroptosis(Degterev et al. 2008, Amin et al. 2018, Sarhan et al. 2018, Wegner, Saleh and Degterev 2017).