Virus Induced Signaling Adapter (VISA)

These interactions initiate signaling pathways that differ in their initial steps but converge in the activation of the protein kinases IKKA (CHUK) and IKKB (IKBKB), which activate NFKB , or TBK1 and IKKE (IKBKE), which activate IRF3. Activated IRF3 and NFKB induce transcription of IFNB (IFNB1). For the TLR3 pathway, the intermediary molecule before the pathways converge is the cytoplasmic protein TRIF (TICAM1). For RIGI, the intermediary protein is mitochondria-bound IPS1 (Sen and Sarkar, 2005).

Present in T-cells, monocytes, epithelial cells and hepatocytes (at protein level). Ubiquitously expressed, with highest levels in heart, skeletal muscle, liver, placenta and peripheral blood leukocytes.