Overview:

RIPK1 or Receptor Interacting Protein Kinase 1 is a serine/threonine kinase that was originally identified as interacting with the cytoplasmic domain of FAS. RIPK1 has been deemed as an important element in the signal transduction machinery that mediates programmed cell death. RIPK1 has been shown to interact with TRADD, TRAF1 TRAF2 and TRAF3 and TRADD can act as an adaptor protein to recruit RIPK1 to the TNFR1 complex in a TNF-dependent process (1). TNFα is capable of activating the noncanonical NF-κB pathway, but this activation of this pathway is negatively regulated by RIPK1 (2).

References:

1. Hsu, H. et al: TNF-dependent recruitment of the protein kinase RIP to the TNF receptor-1 signaling complex. Immunity 4: 387-396, 1996.

2. Kim, J Y. et al: TNFα induced noncanonical NF-κB activation is attenuated by RIP1 through stabilization of TRAF2. J Cell Sci. 2011 Feb 15;124(Pt 4):647-56.