Spencer Ambre, Yu Lingli, Guili Vincent, Reynaud Florie, Ding Yindi, Ma Ji, Jullien Jérôme, Koubi David, Gauthier Emmanuel, Cluet David, Falk Julien, Castellani Valérie, Yuan Chonggang, Rudkin Brian B
East China Normal University, Key Laboratory of Brain Functional Genomics of the Ministry of Education of PR China, Joint Laboratory of Neuropathogenesis, ECNU, ENS Lyon, CNRS, Shanghai 200062, China.
Univ. Lyon, Ecole normale supérieure de Lyon, Université Claude Bernard Lyon 1, CNRS, Differentiation & Cell Cycle Group, Laboratoire de Biologie Moléculaire de la Cellule, UMR5239, 69007 Lyon, France.
Int J Mol Sci. 2017 Mar 24;18(4):693. doi: 10.3390/ijms18040693.
Membrane microdomains or "lipid rafts" have emerged as essential functional modules of the cell, critical for the regulation of growth factor receptor-mediated responses. Herein we describe the dichotomy between caveolin-1 and caveolin-2, structural and regulatory components of microdomains, in modulating proliferation and differentiation. Caveolin-2 while caveolin-1 nerve growth factor (NGF) signaling and subsequent cell differentiation. Caveolin-2 does not appear to impair NGF receptor trafficking but elicits prolonged and stronger activation of MAPK (mitogen-activated protein kinase), Rsk2 (ribosomal protein S6 kinase 2), and CREB (cAMP response element binding protein). In contrast, caveolin-1 does not alter initiation of the NGF signaling pathway activation; rather, it acts, at least in part, by sequestering the cognate receptors, TrkA and p75, at the plasma membrane, together with the phosphorylated form of the downstream effector Rsk2, which ultimately prevents CREB phosphorylation. The non-phosphorylatable caveolin-1 serine 80 mutant (S80V), no longer inhibits TrkA trafficking or subsequent CREB phosphorylation. MC192, a monoclonal antibody towards p75 that does not block NGF binding, prevents exit of both NGF receptors (TrkA and p75) from lipid rafts. The results presented herein underline the role of caveolin and receptor signaling complex interplay in the context of neuronal development and tumorigenesis.
膜微区或“脂筏”已成为细胞的重要功能模块,对生长因子受体介导的反应调节至关重要。在此我们描述了脂筏的结构和调节成分小窝蛋白-1和小窝蛋白-2在调节增殖和分化方面的二分法。小窝蛋白-2 而小窝蛋白-1 神经生长因子(NGF)信号传导及随后的细胞分化。小窝蛋白-2似乎不会损害NGF受体的运输,但会引发丝裂原活化蛋白激酶(MAPK)、核糖体蛋白S6激酶2(Rsk2)和cAMP反应元件结合蛋白(CREB)的延长且更强的激活。相比之下,小窝蛋白-1不会改变NGF信号通路激活的起始;相反,它至少部分地通过在质膜上隔离同源受体TrkA和p75以及下游效应器Rsk2的磷酸化形式来发挥作用,这最终阻止了CREB的磷酸化。不可磷酸化的小窝蛋白-1丝氨酸80突变体(S80V)不再抑制TrkA的运输或随后的CREB磷酸化。MC192是一种针对p75的单克隆抗体,不阻断NGF结合,可阻止两种NGF受体(TrkA和p75)从脂筏中退出。本文给出的结果强调了小窝蛋白和受体信号复合物相互作用在神经元发育和肿瘤发生背景下的作用。