Catalyzes the specific attachment of an amino acid to its cognate tRNA in a 2 step reaction: the amino acid (AA) is first activated by ATP to form AA-AMP and then transferred to the acceptor end of the tRNA ( ). When secreted, acts as a signaling molecule that induces immune response through the activation of monocyte/macrophages . Catalyzes the synthesis of the signaling molecule diadenosine tetraphosphate (Ap4A), and thereby mediates disruption of the complex between HINT1 and MITF and the concomitant activation of MITF transcriptional activity ( , ).
(Microbial infection) Interacts with HIV-1 virus GAG protein, facilitating the selective packaging of tRNA(3)(Lys), the primer for reverse transcription initiation.
Subcellular locations: Cytoplasm, Cytosol, Cytoplasm, Nucleus, Cell membrane, Secreted
Secretion is induced by TNF-alpha . Cytosolic in quiescent mast cells. Translocates into the nucleus in response to mast cell activation by immunoglobulin E .
Subcellular locations: Mitochondrion