Secretory phospholipase A2 receptor
Short name=PLA2-R
Short name=PLA2R
Alternative name(s):
180 kDa secretory phospholipase A2 receptor
C-type lectin domain family 13 member C
M-type receptor
Cleaved into the following chain:
Soluble secretory phospholipase A2 receptor
Short name=Soluble PLA2-R
Short name=Soluble PLA2R
Function
分泌型ホスホリパーゼA2（sPLA2）の受容体。ヘビのPA2様毒素とも結合する。機能は不明な点が多いが、sPLA2の除去と同様sPLA2の正負両方の調節に関与しているとされる。細胞の種類によって異なる作用をもち、骨髄由来のマスト細胞ではアラキドン酸由来のメディエーターの合成によるMAPKの活性化による増殖促進。好中球では、p38MAPKの活性化によりエラスターゼ分泌と細胞の接着を促進する。おそらく、エンドトキシンショックの際に前炎症性サイトカインの産生にかかわる。もう１つはsPLA2の貪食によりPLA2の活性を抑制する機能もある。
Receptor for secretory phospholipase A2 (sPLA2). Acts as a receptor for phosholipase sPLA2-IB/PLA2G1B but not sPLA2-IIA/PLA2G2A. Also able to bind to snake PA2-like toxins. Although its precise function remains unclear, binding of sPLA2 to its receptor participates in both positive and negative regulation of sPLA2 functions as well as clearance of sPLA2. Binding of sPLA2-IB/PLA2G1B induces various effects depending on the cell type, such as activation of the mitogen-activated protein kinase (MAPK) cascade to induce cell proliferation, the production of lipid mediators, selective release of arachidonic acid in bone marrow-derived mast cells. In neutrophils, binding of sPLA2-IB/PLA2G1B can activate p38 MAPK to stimulate elastase release and cell adhesion. May be involved in responses in proinflammatory cytokine productions during endotoxic shock. Also has endocytic properties and rapidly internalizes sPLA2 ligands, which is particularly important for the clearance of extracellular sPLA2s to protect their potent enzymatic activities. The soluble secretory phospholipase A2 receptor form is circulating and acts as a negative regulator of sPLA2 functions by blocking the biological functions of sPLA2-IB/PLA2G1B. Ref.1 Ref.7
Subcellular location
Cell membrane; Single-pass type I membrane protein By similarity.
Soluble secretory phospholipase A2 receptor: Secreted By similarity.
Isoform 2: Secreted Potential.
Tissue specificity
Present in lung macrophage (at protein level). Highly expressed in kidney. Also expressed in pancreas, amnion, choriodecidua and placenta. Isoform 2 is expressed at much lower level. Ref.1 Ref.5 Ref.6 Ref.7
Domain
C-type lectin domains 3-5 mediate the interaction with phospholipase PLA2G1B.
The endocytosis signal probably mediates endocytosis via clathrin-coated pits By similarity.
Post-translational modification
The secretory phospholipase A2 receptor form may be produced by the action of metalloproteinases. It contains all extracellular domains and only lacks transmembrane and cytosolic regions. It is however unclear whether this form is produced by proteolytic cleavage as suggested by some experiments, or by alternative splicing, as in the case of isoform 2 that shares all characteristics of secretory phospholipase A2 receptor form By similarity.
Sequence similarities
Contains 8 C-type lectin domains.
Contains 1 fibronectin type-II domain.
Contains 1 ricin B-type lectin domain.
