Aim. To show that CHI3L2 activates the extracellular signal regulated kinase (ERK1/ERK2) mediated cascade similarly to the homologous CHI3L1 protein. Methods. The involvement of CHI3L2 in ERK1/ERK2 phosphorylation was evaluated by Western blotting with either polyclonal anti-ERK1/ERK2 or monoclonal anti- phospho-ERK1/ERK2 antibodies. Results. The checking of CHI3L2 possibility to initiate MAPK cascade showed the phosphorylation of ERK1/ERK2 in HEK293 after addition of CHI3L2 to DMEM. Conclusions. Chitinase-like protein CHI3L2 activates phosphorylation of ERK1/ERK2 in human embryonic kidney cells (HEK293) and thus initiates the MAP kinase signaling cascade which may lead to increased cell proliferation or differentiation.

Keywords: chitinase 3-like protein 1 (CHI3L1, HC gp-39, YKL- 40), chitinase 3-like protein 2 (CHI3L2, YKL-39), MAP kinase, ERK1/ERK2.