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Annexin A1/ANXA1

OverviewProducts

Domain

The full-length protein can bind eight Ca(2+) ions via the annexin repeats. Calcium binding causes a major conformation change that modifies dimer contacts and leads to surface exposure of the N-terminal phosphorylation sites; in the absence of Ca(2+), these sites are buried in the interior of the protein core. The N-terminal region becomes disordered in response to calcium-binding.

The N-terminal 26 amino acids are sufficient for its extracellular functions in the regulation of inflammation and wound healing (PubMed:25664854). Acylated peptides that contain the first 26 amino acids of the mature protein can activate signaling via the formyl peptide receptors (PubMed:15187149, PubMed:25664854).

Function

Plays important roles in the innate immune response as effector of glucocorticoid-mediated responses and regulator of the inflammatory process. Has anti-inflammatory activity (PubMed:8425544). Plays a role in glucocorticoid-mediated down-regulation of the early phase of the inflammatory response (By similarity). Promotes resolution of inflammation and wound healing (PubMed:25664854). Functions at least in part by activating the formyl peptide receptors and downstream signaling cascades (PubMed:15187149, PubMed:25664854). Promotes chemotaxis of granulocytes and monocytes via activation of the formyl peptide receptors (PubMed:15187149). Contributes to the adaptive immune response by enhancing signaling cascades that are triggered by T-cell activation, regulates differentiation and proliferation of activated T-cells (PubMed:17008549). Promotes the differentiation of T-cells into Th1 cells and negatively regulates differentiation into Th2 cells (PubMed:17008549). Has no effect on unstimulated T cells (PubMed:17008549). Promotes rearrangement of the actin cytoskeleton, cell polarization and cell migration (PubMed:15187149). Negatively regulates hormone exocytosis via activation of the formyl peptide receptors and reorganization of the actin cytoskeleton (PubMed:19625660). Has high affinity for Ca(2+) and can bind up to eight Ca(2+) ions (By similarity). Displays Ca(2+)-dependent binding to phospholipid membranes (PubMed:2532504, PubMed:8557678). Plays a role in the formation of phagocytic cups and phagosomes. Plays a role in phagocytosis by mediating the Ca(2+)-dependent interaction between phagosomes and the actin cytoskeleton (By similarity).

Post-translational modifications

Phosphorylated by protein kinase C, EGFR and TRPM7 (PubMed:2457390, PubMed:15485879). Phosphorylated in response to EGF treatment (PubMed:2532504).

Sumoylated.

Sequence similarities

Belongs to the annexin family.

Tissue specificity

Detected in resting neutrophils (PubMed:10772777). Detected in peripheral blood T-cells (PubMed:17008549). Detected in extracellular vesicles in blood serum from patients with inflammatory bowel disease, but not in serum from healthy donors (PubMed:25664854). Detected in placenta (at protein level) (PubMed:2532504). Detected in liver.

Cellular localization

  • Nucleus
  • Cytoplasm
  • Cell projection
  • Cilium
  • Cell membrane
  • Membrane
  • Peripheral membrane protein
  • Endosome membrane
  • Peripheral membrane protein
  • Basolateral cell membrane
  • Apical cell membrane
  • Lateral cell membrane
  • Secreted
  • Secreted
  • Extracellular space
  • Cell membrane
  • Peripheral membrane protein
  • Extracellular side
  • Secreted
  • Extracellular exosome
  • Cytoplasmic vesicle
  • Secretory vesicle lumen
  • Cell projection
  • Phagocytic cup
  • Early endosome
  • Cytoplasmic vesicle membrane
  • Peripheral membrane protein
  • Secreted, at least in part via exosomes and other secretory vesicles. Detected in exosomes and other extracellular vesicles (PubMed:25664854). Alternatively, the secretion is dependent on protein unfolding and facilitated by the cargo receptor TMED10; it results in the protein translocation from the cytoplasm into ERGIC (endoplasmic reticulum-Golgi intermediate compartment) followed by vesicle entry and secretion (PubMed:32272059). Detected in gelatinase granules in resting neutrophils (PubMed:10772777). Secretion is increased in response to wounding and inflammation (PubMed:25664854). Secretion is increased upon T-cell activation (PubMed:17008549). Neutrophil adhesion to endothelial cells stimulates secretion via gelatinase granules, but foreign particle phagocytosis has no effect (PubMed:10772777). Colocalizes with actin fibers at phagocytic cups (By similarity). Displays calcium-dependent binding to phospholipid membranes (PubMed:2532504, PubMed:8557678).

Alternative names

  • Annexin A1
  • Annexin I
  • Annexin-1
  • Calpactin II
  • Calpactin-2
  • Chromobindin-9
  • Lipocortin I
  • Phospholipase A2 inhibitory protein
  • p35
  • ANXA1
  • LPC1
  • ANX1

Database links

Target type

Proteins

Primary research area

Immuno-oncology

Molecular weight

38714Da