The STK3 (Serine/Threonine Kinase 3) and STK4 (Serine/Threonine Kinase 4) proteins, also known as MST2 and MST1. respectively, are core components of the Hippo signaling pathway, a conserved regulator of tissue homeostasis, organ size, and apoptosis. These kinases function as tumor suppressors by phosphorylating downstream effectors like LATS1/2. which in turn inhibit YAP/TAZ transcriptional co-activators to control cell proliferation and survival. Dysregulation of STK3/STK4 is implicated in cancer, immune disorders, and neurodegenerative diseases.
Antibodies targeting STK3/STK4 are critical tools for studying Hippo pathway dynamics. They enable detection of protein expression levels, subcellular localization (e.g., cytoplasmic vs. nuclear), and activation status through phosphorylation-specific epitopes (e.g., Thr180/Thr183 in STK3/STK4). Such antibodies are widely used in techniques like Western blotting, immunohistochemistry, and immunofluorescence. Researchers also utilize them to investigate kinase interactions, pathway crosstalk (e.g., with Wnt or TGF-β signaling), and therapeutic responses in disease models. Due to high sequence homology between STK3 and STK4. some antibodies may cross-react, necessitating careful validation via knockout controls. Recent studies explore STK3/STK4 inhibition as a strategy to enhance tissue regeneration or counteract YAP/TAZ-driven malignancies, further driving demand for specific, high-affinity antibodies in both basic and translational research.