Table 1: TBK1, IKK family, and their characteristics.


Subtype

Domains

Phosphorylation site
Sequence identity (%)

Function

Reference
IKK IKK

Canonical
IKKs
 IKK KD, LZ, HLH, NBDS176/18010027Osteoclast differentiation; skin tumor suppressor; T-cell receptor signaling pathway; virus response; Toll-like receptor signaling pathway[2629]
 IKK KD, ULD, LZ, HLH, NBDS177/1815224Mediates chemoresistance for cell survival and death; regulates hepatic fibrosis[30, 31]
 IKK CC1, CC2, LZ, ZFS376None
reported
None
reported
Regulates IκB kinase (IKK) complex, involved in inflammation, immunity, cell survival[32, 33]

Noncanonical
IKKs
 IKK KD, ULD, LZ, HLHS17227100Regulates type I and type II interferon responses[34]
 TBK1KD, ULD, LZ, HLHS1722764Regulates type I and type II interferon responses, mediates NF- B signaling, liver degeneration, cancer, hepatitis, colitis, and rheumatoid arthritis[20, 22, 25, 28, 35, 36]

KD: kinase domain; HLH: helix-loop-helix; ULD: ubiquitin-like domain; LZ: leucine zipper; CC1: first coiled coil; CC2: second coiled coil; ZF: zinc finger.