TREM1

This gene encodes a receptor belonging to the Ig superfamily that is expressed on myeloid cells. This protein amplifies neutrophil and monocyte-mediated inflammatory responses triggered by bacterial and fungal infections by stimulating release of pro-inflammatory chemokines and cytokines, as well as increased surface expression of cell activation markers. Alternatively spliced transcript variants encoding different isoforms have been noted for this gene.[provided by RefSeq, Jun 2011]

TREM1 Gene(Protein Coding) Triggering Receptor Expressed On Myeloid Cells 1

Isoform 1
Cell surface receptor that plays important roles in innate and adaptive immunity by amplifying inflammatory responses (PubMed:10799849, PubMed:21393102).
Upon activation by various ligands such as PGLYRP1, HMGB1 or HSP70, multimerizes and forms a complex with transmembrane adapter TYROBP/DAP12 (PubMed:25595774, PubMed:17568691, PubMed:29568119).
In turn, initiates a SYK-mediated cascade of tyrosine phosphorylation, activating multiple downstream mediators such as BTK, MAPK1, MAPK3 or phospholipase C-gamma (PubMed:21659545, PubMed:14656437).
This cascade promotes the neutrophil- and macrophage-mediated release of pro-inflammatory cytokines and/or chemokines, as well as their migration and thereby amplifies inflammatory responses that are triggered by bacterial and fungal infections (PubMed:17568691, PubMed:17098818).
By also promoting the amplification of inflammatory signals that are initially triggered by Toll-like receptor (TLR) and NOD-like receptor engagement, plays a major role in the pathophysiology of acute and chronic inflammatory diseases of different etiologies including septic shock and atherosclerosis (PubMed:21393102, PubMed:11323674).
Isoform 2
Acts as a decoy receptor, counterbalancing TREM1 pro-inflammatory activity through the neutralization of its lignad.

Biological Process acute inflammatory response Source:InterPro
Biological Process adaptive immune response Source:UniProtKB-KW
Biological Process humoral immune response Source:ProtInc1 Publication
Biological Process innate immune response Source:UniProtKB-KW
Biological Process intracellular signal transduction Source:ProtInc1 Publication
Biological Process neutrophil chemotaxis Source:GO_Central1 Publication
Biological Process neutrophil-mediated killing of gram-negative bacterium Source:GO_Central1 Publication

Isoform 1
Cell membrane
Recruited to lipid rafts when activated.
Isoform 2
Secreted

Extracellular: 21-205
Helical: 206-226
Cytoplasmic: 227-234

Glycosylated.