EPRS, Bifunctional glutamate/proline--tRNA ligase
Enzyme Classification 126.96.36.199
Also Known as
SYEP_HUMAN, EPRS, GLNS, PARS, QARS, QPRS
Multifunctional protein which is primarily part of the aminoacyl-tRNA synthetase multienzyme complex, also know as multisynthetase complex, that catalyzes the attachment of the cognate amino acid to the corresponding tRNA in a two-step reaction: the amino acid is first activated by ATP to form a covalent intermediate with AMP and is then transferred to the acceptor end of the cognate tRNA (PubMed:1756734, PubMed:24100331, PubMed:23263184). The phosphorylation of EPRS, induced by interferon-gamma, dissociates the protein from the aminoacyl-tRNA synthetase multienzyme complex and recruits it to the GAIT complex that binds to stem loop-containing GAIT elements in the 3'-UTR of diverse inflammatory mRNAs (such as ceruplasmin), suppressing their translation. Interferon-gamma can therefore redirect, in specific cells, the EPRS function from protein synthesis to translation inhibition (PubMed:15479637, PubMed:23071094). Also functions as an effector of the mTORC1 signaling pathway by promoting, through SLC27A1, the uptake of long-chain fatty acid by adipocytes. Thereby, it also plays a role in fat metabolism and more indirectly influences lifespan (PubMed:28178239). Homodimer (PubMed:24100331, PubMed:23263184). Part of the aminoacyl-tRNA synthetase multienzyme complex, also know as multisynthetase complex (MSC), that is composed of the tRNA ligases for Arg (RARS), Asp (DARS), Gln (QARS), Ile (IARS), Leu (LARS), Lys (KARS), Met (MARS) the bifunctional ligase for Glu and Pro (EPRS) and the auxiliary subunits AIMP1/p43, AIMP2/p38 and EEF1E1/p18 (PubMed:24312579, PubMed:19131329, PubMed:19289464). Forms a linear complex that contains MARS, EEF1E1, EPRS and AIMP2 that is at the core of the multisubunit complex (PubMed:26472928). Interacts with TARSL2 (PubMed:24312579). Interacts with DUS2L (PubMed:15994936). Component of the GAIT complex which is composed of EPRS, RPL13A and GAPDH. For human, the complex assembly seems to be a two-step process in which EPRS first associates with SYNCRIP to form a pre-GAIT complex which is deficient in GAIT element binding (PubMed:15479637). Interacts (phosphorylated at Ser-999) with SLC27A1; mediates the translocation of SLC27A1 from the cytoplasm to the plasma membrane thereby increasing the uptake of long-chain fatty acids (PubMed:28178239).