STE20-related kinase adapter protein alpha (STRADA)

STE20-related kinase adapter protein alpha (STRADA) is a pseudokinase that acts as an essential adaptor for the tumor suppressor kinase LKB1 (STK11)[1][3][8]. Despite possessing a STE20-like kinase domain, it lacks key residues for catalytic activity. STRADA forms a heterotrimeric complex with LKB1 and the scaffolding protein CAB39 (MO25), promoting LKB1 activation and subcellular localization by sequestering it in the cytoplasm[1][2][3][5]. This activation is critical for LKB1-induced G1 cell cycle arrest, regulation of cell polarity, and metabolic homeostasis. Pathogenic mutations in STRADA cause polyhydramnios-megalencephaly-symptomatic epilepsy (PMSE) syndrome, and STRADA loss-of-function can lead to mTORC1 hyperactivation and disrupted neuronal development[1][3][7]. STRADA’s role as an adaptor in signal transduction links it indirectly to cancer and neurological diseases, especially through the LKB1/mTOR signaling axis[3][7]. There are currently no known drugs that directly target STRADA, but its pathway may be pharmacologically modulated via upstream or downstream effectors.

Other names

STRADSTRAD alphaLYK5PMSENY-BR-96StlkSTE20-related adapter proteinSerologically defined breast cancer antigen NY-BR-96STE20-like pseudokinaseSTE20-related adaptor-alpha