PLA2G3 Q9NZ20

第3组分泌型磷脂酶A2 (EC 3.1.1.4) (第III组分泌型磷脂酶A2) (GIII sPLA2) (sPLA2-III) (磷脂酰胆碱2-酰基水解酶3)

功能描述

分泌型钙依赖性磷脂酶A2，主要靶向细胞外磷脂。水解连接在磷脂sn-2位置的脂肪酰基酯键，无明显头部基团选择性 (PubMed:12522102, PubMed:15863501, PubMed:18801741, PubMed:28947740)。参与低密度脂蛋白(LDL)和高密度脂蛋白(HDL)颗粒的磷脂重塑。水解LDL磷脂释放不饱和脂肪酸，调节巨噬细胞分化为泡沫细胞 (PubMed:18801741)。可能以自分泌和旁分泌方式起作用 (PubMed:23624557)。由未成熟肥大细胞分泌，作用于附近的成纤维细胞，在PTDGS上游合成前列腺素D2 (PGD2)，进而通过PTGDR促进肥大细胞成熟和脱颗粒 (PubMed:23624557)。由附睾上皮分泌，作用于导管内的未成熟精子细胞，调节顶体组装和精子运动所需的磷脂酰胆碱脂肪酰基组分的不饱和度。促进精子膜磷脂酰胆碱中的脂肪酰链从omega-6和omega-9替换为omega-3多不饱和脂肪酸(PUFAs)。与脂氧合酶途径偶联，可能在雄性生殖道中加工omega-6 PUFAs以生成氧化脂质介质 (By similarity)。在中心体周围纤毛前区室，可能通过调节纤毛膜蛋白的内吞循环来负向调控纤毛发生 (PubMed:20393563)。与环氧合酶途径偶联，提供花生四烯酸以生成前列腺素E2 (PGE2)，这是一种在炎症和肿瘤发生中起作用的强效免疫调节脂质 (PubMed:12522102, PubMed:15863501)。在结肠上皮屏障，优先水解sn-2位含有花生四烯酸和二十二碳六烯酸的磷脂，参与生成与结肠干细胞稳态有关的氧化代谢产物 (PubMed:28947740)。从神经元质膜释放C16:0和C18:0溶血磷脂酰胆碱亚类，促进神经突生长和神经元存活 (PubMed:17868035)。 {ECO:0000250|UniProtKB:Q8BZT7, ECO:0000269|PubMed:12522102, ECO:0000269|PubMed:15863501, ECO:0000269|PubMed:17868035, ECO:0000269|PubMed:18801741, ECO:0000269|PubMed:20393563, ECO:0000269|PubMed:23624557, ECO:0000269|PubMed:28947740}。

组织特异性

Expressed in kidney, heart, liver, and skeletal muscle. Also present in placenta and peripheral blood leukocytes. Not detected in colon, thymus, spleen and small intestine. In lung, expressed in bronchial epithelial cells and alveolar macrophages, but scarcely detected in alveolar epithelium, arterial walls and interstitial fibroblasts (at protein level). In joints of osteoarthritis and rheumatoid arthritis, expressed in endothelial cells (at protein level). In normal heart, detected in some vessels. In myocardial tissues with acute infarction, expressed in vascular endothelial cells adjacent to cardiomyocytes and those in lesions with granulation. Expression in cardiomyocytes is scarce (at protein level). In uterus, breast and colon cancers, detected in tumor cells and neighboring microvascular endothelium, but not in normal glandular tissues (at protein level) (PubMed:15863501). Expressed in dermal resting mast cells (at protein level) and pulmonary mast cells (PubMed:23624557). Expressed in neuronal fibers (at protein level) (PubMed:17868035). Highly expressed in dorsal root ganglia neurons (at protein level) (PubMed:17868035). Expressed in Purkinje cells in cerebellum (at protein level) (PubMed:17868035). In stomach is preferentially expressed in neuronal fibers and in microvascular endothelium (PubMed:17868035). Sparsely expressed in normal aorta (at protein level). Highly expressed in macrophages and smooth muscle cells in aorta with atheroma (PubMed:18801741).

亚细胞定位

Secreted