Clattenburg Leanne, Wigerius Michael, Qi Jiansong, Rainey Jan K, Rourke Jillian L, Muruganandan Shanmugam, Sinal Christopher J, Fawcett James P
Department of Pharmacology, Dalhousie University, Halifax, NS, Canada.
Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada.
Mol Cell Biol. 2015 Jul;35(13):2265-77. doi: 10.1128/MCB.00062-15. Epub 2015 Apr 27.
Deregulation of cellular polarity proteins and their associated complexes leads to changes in cell migration and proliferation. The nitric oxide synthase 1 adaptor protein (NOS1AP) associates with the tumor suppressor protein Scribble to control cell migration and oncogenic transformation. However, how NOS1AP is linked to the cell signaling events that curb oncogenic progression has remained elusive. Here we identify several novel NOS1AP isoforms, NOS1APd, NOS1APe, and NOS1APf, with distinct cellular localizations. We show that isoforms with a membrane-interacting phosphotyrosine binding (PTB) domain can associate with Scribble and recognize acidic phospholipids. In a screen to identify novel binding proteins, we have discovered a complex consisting of NOS1AP and the transcriptional coactivator YAP linking NOS1AP to the Hippo signaling pathway. Silencing of NOS1AP reduces the phosphorylation of YAP and of the upstream kinase Lats1. Conversely, expression of NOS1AP promotes YAP and Lats1 phosphorylation, which correlates with reduced TEAD activity and restricted cell proliferation. Together, these data implicate a role for NOS1AP in the regulation of core Hippo signaling and are consistent with the idea that NOS1AP functions as a tumor suppressor.
细胞极性蛋白及其相关复合物的失调会导致细胞迁移和增殖的改变。一氧化氮合酶1衔接蛋白（NOS1AP）与肿瘤抑制蛋白Scribble结合，以控制细胞迁移和致癌转化。然而，NOS1AP如何与抑制致癌进程的细胞信号事件相关联仍不清楚。在这里，我们鉴定了几种新的NOS1AP异构体，即NOS1APd、NOS1APe和NOS1APf，它们具有不同的细胞定位。我们发现，具有膜相互作用磷酸酪氨酸结合（PTB）结构域的异构体可以与Scribble结合并识别酸性磷脂。在一项鉴定新结合蛋白的筛选中，我们发现了一个由NOS1AP和转录共激活因子YAP组成的复合物，该复合物将NOS1AP与Hippo信号通路联系起来。沉默NOS1AP会降低YAP和上游激酶Lats1的磷酸化水平。相反，NOS1AP的表达会促进YAP和Lats1的磷酸化，这与TEAD活性降低和细胞增殖受限相关。这些数据共同表明NOS1AP在核心Hippo信号调节中发挥作用，并且与NOS1AP作为肿瘤抑制因子的观点一致。
