| Popis: |
The TNF-receptor-associated factors (TRAFs), which currently consist of six members (TRAFl-6) in mammals, have emerged to be the major adapter proteins for these receptors. Through versatile protein-protein interactions,TRAFs link receptor activation to downstream kinase activation and eventually the stimulation of nuclear factor KB (NF-KB) and AP-1 transcriptional activity. Collectively, a wide range of cellular effects including cell survival, proliferation, and differentiation may be elicited by TRAP signaling. The TRAFs participate in receptor signal transduction by either direct association with receptors or indirect interaction through additional adapter proteins, in at least three distinct pathways. Members of the TNF receptor superfamily that do not contain intracellular death domains, such as TNF-R2 and CD40, recruit TRAFs directly via short sequences in their intracellular tails. The Epstein-Barr virus transforming protein LMPl has also been shown to directly recruit TRAFs for viral survival and cell transformation. Members of the TRAF family are characterized by the presence of a novel TRAF domain at the C terminus which in turn consists of a coiled-coil domain followed by a conserved TRAF-C domain 1. The TRAF domain plays an important role in TRAF function by mediating self-association, receptor interaction, and interactions with other signaling proteins such as TRADD and IRAK. |
