TKL-Unique

TKL-Unique gathers the diverse TKL-group enzymes that cannot be assigned to the IRAK, LRRK, MLK, RAF, RIPK, or STKR families. The branch mixes catalytically active serine/threonine kinases with pseudokinases such as the Tribbles proteins (TRIB1-3), which lack key catalytic residues and instead recruit the COP1 ubiquitin ligase to degrade substrates like C/EBP-alpha, regulating metabolism and myeloid leukemogenesis. Members act as node-like regulators of protein turnover, adhesion, vesicle trafficking, and stress signaling rather than as canonical cascade tiers. Their heterogeneity makes each a bespoke research target, and recombinant proteins support interaction and degradation-pathway studies.