Overview:

TBK1, also known as NAK or NFkB-activating kinase, is an upstream protein kinase that can phosphorylate and activate the IkB kinases (1). Activation of IkB kinases allows the phosphorylation of IkB protein which is then degraded via the ubiquitination pathway. This mechanism allows the activation of the NFkB transcriptional complex. TBK1 is a specific upstream regulator of IkB kinases and can also interact and the IkB protein TANK. TBK1 is a component of the virus-activated kinase that phosphorylate IRF3 and IRF7 allowing their dimerization and translocation to the nucleus, where they induce transcription of interferon (2).

References:

1. Tojima, Y. et al: NAK is an I-kappa-B kinase-activating kinase. Nature 404: 778-782, 2000.2.Sharma, S. et al: Triggering the interferon antiviral response through an IKK-related pathway. Science 300: 1148-1151, 2003.