Myoferlin regulates vascular endothelial growth factor receptor-2 stability and function
Myoferlin regulates vascular endothelial growth factor receptor-2 stability and function
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DOI：
10.1074/jbc.m704798200
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发表时间：
2007-10-19
影响因子：
4.8
通讯作者：
Sessa, William C.
中科院分区：
文献类型：
--
作者：
Bernatchez, Pascal N.;Acevedo, Lisette;Sessa, William C.
肌铁蛋白和异铁蛋白是膜蛋白家族的成员。最近的研究表明，肌铁蛋白或异铁蛋白的突变或遗传破坏可促进小鼠肌营养不良相关表型，这是质膜完整性受损的结果。然而，肌钙素在非肌肉组织中没有生物学功能。本文中，通过对内皮细胞（EC）小泡/脂筏微结构域的蛋白质组学分析，我们在这些结构域中发现了肌钙蛋白，并表明肌钙蛋白在内皮细胞和血管组织中高度表达。肌钙素的缺失导致血管内皮生长因子（VEGF）作用下缺乏增殖、迁移和一氧化氮（NO）释放。Western blotting和表面生物素化实验表明，myoferlin的缺失降低了天然内皮细胞中VEGF受体-2 （VEGFR-2）的表达水平和自磷酸化水平。在重建的细胞系统中，转染myoferlin增加了VEGFR-2膜的表达和自磷酸化，以响应VEGF。在体内，肌钙蛋白缺乏小鼠的VEGFR-2水平和vegf诱导的通透性受损。在机制上，myoferlin与dynamin-2和VEGFR-2形成复合物，阻止cbl依赖性的VEGFR-2多泛素化和蛋白酶体降解。这些数据首次报道了myoferlin的新生物活性，并揭示了膜完整性对VEGF信号传导的作用。
Myoferlin and dysferlin are members of the ferlin family of membrane proteins. Recent studies have shown that mutation or genetic disruption of myoferlin or dysferlin promotes muscular dystrophy-related phenotypes in mice, which are the result of impaired plasma membrane integrity. However, no biological functions have been ascribed to myoferlin in non-muscle tissues. Herein, using a proteomic analysis of endothelial cell ( EC) caveolae/lipid raft microdomains we identified myoferlin in these domains and show that myoferlin is highly expressed in ECs and vascular tissues. The loss of myoferlin results in lack of proliferation, migration, and nitric oxide ( NO) release in response to vascular endothelial growth factor ( VEGF). Western blotting and surface biotinylation experiments show that loss of myoferlin reduces the expression level and autophosphorylation of VEGF receptor-2 ( VEGFR-2) in native ECs. In a reconstituted cell system, transfection of myoferlin increases VEGFR-2 membrane expression and autophosphorylation in response to VEGF. In vivo, VEGFR-2 levels and VEGF-induced permeability are impaired in myoferlin-deficient mice. Mechanistically, myoferlin forms a complex with dynamin-2 and VEGFR-2, which prevents CBL-dependent VEGFR-2 polyubiquitination and proteasomal degradation. These data are the first to report novel biological activities for myoferlin and reveal the role of membrane integrity to VEGF signaling.