Description
LMTK3, or Lemur tyrosine kinase 3, belongs to the LMR subfamily of tyr protein kinases. LMTK3 decreases the activity of protein kinase C (PKC) and also leads to phosphorylation of AKT (Ser473), thereby increasing binding of forkhead box O3 (FOXO3) to the ESR1 promoter. LMTK3 phosphorylates ERα, protecting it from proteasomal degradation in vitro. Knockdown of LMTK3 leads to a reduction of tumor volume in an orthotopic mouse model and abrogates proliferation of ERα+ but not ERα- cells, indicative of its role in ERα activity. These findings reveal LMTK3 as a new therapeutic target for breast cancer