GRAPHICAL ABSTRACT.

Schematic representation of TLQP-21 intracellular transduction mechanism in CHO cells. TLQP-21, by binding a G protein coupled receptor (GPCR), activates PLCβ that in turn produces DAG and IP₃ as second messengers. These molecules activate PKC, stimulate ERK1/2 phosphorylation and induce intracellular Ca²⁺ release from the ER with the subsequent Ca²⁺ entry from outside the cell. Phosphorylation of AKT is probably a result of the increase in cellular Ca²⁺ concentrations.