NKF3

Novel kinase family 3 contains PEAK1 (SgK269) and PEAK2 (SgK223), enzymes better known as pseudopodium-enriched atypical kinases. Both localize to pseudopodia and lamellipodia, where they assemble integrin-dependent signaling complexes; PEAK1 is reported to sustain FAK and Src activation downstream of integrin beta 1 and to modulate ERK signaling, while its catalytic status is debated because key motifs diverge from consensus. Elevated PEAK1 expression has been documented in breast, colon and other carcinomas and is associated with migration, invasion and epithelial-to-mesenchymal transition. The family is therefore studied more as a signaling scaffold than as a drug target, and recombinant PEAK proteins support interaction and phosphoproteomic studies.