Endothelial-Monocyte Activating Polypeptide II (EMAP II) Human Active Protein

The protein encoded by this gene is a cytokine that is specifically induced by apoptosis, and it is involved in the control of angiogenesis, inflammation, and wound healing. The release of this cytokine renders the tumor-associated vasculature sensitive to tumor necrosis factor. The precursor protein is identical to the p43 subunit, which is associated with the multi-tRNA synthetase complex, and it modulates aminoacylation activity of tRNA synthetase in normal cells. This protein is also involved in the stimulation of inflammatory responses after proteolytic cleavage in tumor cells. Multiple transcript variants encoding different isoforms have been found for this gene. A pseudogene has been identified on chromosome 20. [provided by RefSeq, Dec 2008]

SCYE1 iso2: Non-catalytic component of the multisynthase complex. Stimulates the catalytic activity of cytoplasmic arginyl-tRNA synthase. Binds tRNA. Possesses inflammatory cytokine activity. Negatively regulates TGF-beta signaling through stabilization of SMURF2 by binding to SMURF2 and inhibiting its SMAD7-mediated degradation. Involved in glucose homeostasis through induction of glucagon secretion at low glucose levels. Promotes dermal fibroblast proliferation and wound repair. Regulates KDELR1- mediated retention of HSP90B1/gp96 in the endoplasmic reticulum. Plays a role in angiogenesis by inducing endothelial cell migration at low concentrations and endothelian cell apoptosis at high concentrations. Induces maturation of dendritic cells and monocyte cell adhesion. Modulates endothelial cell responses by degrading HIF-1A through interaction with PSMA7. Defects in AIMP1 are the cause of leukodystrophy hypomyelinating type 3 (HLD3). A severe autosomal recessive hypomyelinating leukodystrophy characterized by early infantile onset of global developmental delay, lack of development, lack of speech acquisition, and peripheral spasticity associated with decreased myelination in the central nervous system. 2 isoforms of the human protein are produced by alternative splicing.

Protein type: Motility/polarity/chemotaxis

Chromosomal Location of Human Ortholog: 4q24

Cellular Component: Golgi apparatus; extracellular space; aminoacyl-tRNA synthetase multienzyme complex; transport vesicle; cell surface; membrane; endoplasmic reticulum; cytoplasm; nucleus; cytosol

Molecular Function: methionine-tRNA ligase activity; protein binding; protein homodimerization activity; cytokine activity; tRNA binding

Biological Process: tRNA aminoacylation for protein translation; cell-cell signaling; apoptosis; negative regulation of endothelial cell proliferation; response to wounding; methionyl-tRNA aminoacylation; glucose metabolic process; gene expression; angiogenesis; signal transduction; inflammatory response; chemotaxis; cell adhesion; leukocyte migration

Disease: Leukodystrophy, Hypomyelinating, 3