GTPBP1 is a translational GTPase that functions in both protein synthesis and mRNA quality control. During translation elongation, GTPBP1 delivers aminoacyl-tRNAs (aa-tRNAs) to the ribosomal A site in a GTP-dependent manner 1, similar to elongation factor eEF1A 2. However, GTPBP1 operates distinctly from canonical elongation factors: GTP hydrolysis is not immediately followed by rapid peptide bond formation, resulting in slow dissociation and delayed tRNA accommodation 2. This kinetic signature enables GTPBP1's primary quality control function—when peptide bond formation is delayed or absent, GTPBP1 retains aa-tRNA in the A site and recruits the exosome to degrade faulty mRNAs engaged in elongation complexes 1. GTPBP1 can also deliver deacylated tRNAs to the A site 1, potentially functioning during cellular stress. Loss-of-function GTPBP1 variants cause a distinct neurodevelopmental syndrome characterized by microcephaly, profound developmental impairment, distinctive facial features, ectodermal defects, progressive spasticity, epilepsy, and brain atrophy 3. Reduced GTPBP1 expression in Drosophila produces motor impairment, demonstrating evolutionary conservation of its neurological role 3. Interestingly, GTPBP1-knockout mice show no overt phenotype, likely due to functional compensation by the homologous protein GTPBP2 4. GTPBP1 variants also show suggestive (though not genome-wide significant) association with degenerative cervical myelopathy 5.