COL4A3 Q01955

IV型胶原α3链 (Goodpasture抗原) [裂解为：Tumstatin]

功能描述

IV型胶原是肾小球基底膜(GBM)的主要结构成分，与层粘连蛋白、蛋白聚糖和entactin/nidogen共同形成“鸡笼状”网状结构。; FUNCTION: Tumstatin是一个对应于胶原alpha 3(IV) NC1结构域的酶切片段，具有抗血管生成和抗肿瘤细胞活性；这两种抗肿瘤特性可能通过非RGD依赖的ITGB3介导的机制进行调节。

组织特异性

Alpha 3 and alpha 4 type IV collagens are colocalized and present in kidney, eye, basement membranes of lens capsule, cochlea, lung, skeletal muscle, aorta, synaptic fibers, fetal kidney and fetal lung. PubMed:8083201 reports similar levels of expression of alpha 3 and alpha 4 type IV collagens in kidney, but PubMed:7523402 reports that in kidney levels of alpha 3 type IV collagen are significantly lower than those of alpha 4 type IV collagen. According to PubMed:8083201, alpha 3 type IV collagen is not detected in heart, brain, placenta, liver, pancreas, extrasynaptic muscle fibers, endoneurial and perineurial nerves, fetal brain, fetal heart and fetal liver. According to PubMed:7523402, alpha 3 type IV collagen is strongly expressed in pancreas, neuroretina and calvaria and not expressed in adrenal, ileum and skin. Isoform 1 and isoform 3 are strongly expressed in kidney, lung, suprarenal capsule, muscle and spleen, in each of these tissues isoform 1 is more abundant than isoform 3. Isoform 1 and isoform 3 are expressed at low levels in artery, fat, pericardium and peripherical nerve, but not in placenta, mesangium, skin, pleura and cultured umbilical endothelial cells.

亚细胞定位

Secreted, extracellular space, extracellular matrix, basement membrane. Note=Colocalizes with COL4A4 and COL4A5 in GBM, tubular basement membrane (TBM) and synaptic basal lamina (BL).