METTL13 at the interface of translational control, protein methylation, and disease biology.

Methyltransferase-like 13 (METTL13) is a member of the methyltransferase-like (METTL) family characterized by two conserved seven-beta-strand(7BS) catalytic domains. Current evidence identifies METTL13 primarily as a dual protein methyltransferase that modifies the translation elongation factor 1 A(eEF1A), including Lys55 dimethylation and N-terminal methylation. Through this best-established mechanism, METTL13 enhances eEF1A GTPase activity, reshapes translation elongation and codon-specific translational output, and promotes protein production in cells. In multiple cancer settings, METTL13 and the eEF1A-K55 methylation axis are associated with increased translational demand, tumor progression, and Ras-driven tumorigenesis. At the same time, accumulating studies indicate that METTL13 functions are strongly context dependent. Beyond its canonical eEF1A-centered role, METTL13 has been linked to additional regulatory programs, including the c-Cbl/SERCA2a axis, RNA-associated pathways, and disease-specific signaling networks, although these noncanonical mechanisms remain less well defined. Intriguingly, METTL13 may also exert protective or tumor-suppressive effects in selected contexts, such as ischemic heart failure, hereditary deafness, and clear cell renal cell carcinoma. In this narrative review, we summarize the structural and functional features of METTL13, its regulatory network, and current evidence for its roles in malignant and non-malignant diseases. By integrating structural features, molecular modification mechanisms, translational control, disease pathophysiology, and early clinical-translation evidence, this review reframes METTL13 as a context-dependent regulator of proteome adaptation and highlights unresolved mechanistic questions regarding substrate specificity, microenvironment-dependent functional outputs, and context-specific intervention strategies.