The Mitogen-Activated Protein Kinase 4 (MAPK4), a member of the atypical MAPK family, diverges from classical MAPKs (ERK, JNK, p38) in structure and signaling. Unlike canonical MAPKs, MAPK4 lacks a conserved TxY activation motif and features a unique N-terminal kinase domain and C-terminal regulatory region. It is activated by stress or growth signals through a non-canonical phosphorylation mechanism. Functionally, MAPK4 regulates diverse cellular processes, including proliferation, differentiation, and stress responses, often via crosstalk with pathways like mTOR and NF-κB. Emerging studies link MAPK4 to diseases such as cancer (e.g., prostate, breast) and neurodegenerative disorders, where it may promote tumor growth or modulate apoptosis.
MAPK4 antibodies are critical tools for studying its expression, localization, and activation. They enable detection in techniques like Western blot, immunoprecipitation, and immunohistochemistry. Specific antibodies targeting phosphorylated residues (e.g., Ser-186/189) help assess its activation status. Commercial antibodies are often validated for reactivity across human, mouse, and rat samples. Research using these antibodies has revealed MAPK4's dual role in cancer—acting as either oncogene or tumor suppressor, depending on context. Additionally, MAPK4 inhibitors are under exploration for therapeutic targeting, highlighting the antibody's role in drug development and mechanistic studies.