EEF2 (eukaryotic translation elongation factor 2) is a critical component of protein synthesis that catalyzes the GTP-dependent ribosomal translocation step during translation elongation, facilitating the coordinated movement of tRNA molecules and mRNA through the ribosome 1. The protein's activity is primarily regulated through phosphorylation at Thr56 by eEF2 kinase (eEF2K), which inactivates EEF2 and inhibits translational elongation 2. EEF2 function is modulated by several regulatory proteins, including PQBP1, which binds to non-phosphorylated EEF2 and suppresses eEF2K-mediated phosphorylation, thereby promoting protein synthesis 2. The protein also interacts with LDHA in a NADH-dependent manner, controlling EEF2's participation in ribosomal translation 3. EEF2 plays important roles in neuroplasticity, particularly in ketamine's antidepressant effects through BDNF translation regulation 4, and in hippocampal mGluR-dependent long-term depression 2. Additionally, EEF2 facilitates translation of specific mRNAs through binding to modified sites, such as ac4C-modified HMGB2 mRNA in hepatocellular carcinoma 5. Pathologically, EEF2 is targeted by bacterial toxins like exotoxin A, leading to ribotoxic stress and inflammasome activation 6, and is associated with muscle atrophy through interaction with circDdb1-867aa protein 7.