Dissociating quaternary structure regulates cell-signaling functions of a secreted human tRNA synthetase.

ABSTRACT: Many tRNA synthetases are homodimers that are catalytically inactive as monomers. An example is the 528-amino acid human tyrosyl-tRNA synthetase, which is made up of an N-terminal catalytic unit (TyrRS(Mini)) and a 164-amino acid C-domain. Although native TyrRS has no known cytokine functions, natural proteolysis of secreted TyrRS releases TyrRS(Mini), which not only has the same aminoacylation activity as native TyrRS but also has strong activity for stimulating migration of polymorphonuclear leukocytes. The migration-stimulating activity is dependent on an ELR tripeptide motif, similar to that in CXC cytokines like IL-8, and also has the familiar bell-shaped concentration dependence seen for CXC cytokines. Here we show that in contrast to IL-8, where the bell-shaped dependence arises fro

SUBMITTER: Vo MN 

PROVIDER: S-EPMC3064210 | biostudies-literature | 2011 Apr

REPOSITORIES: biostudies-literature