Department of Biochemistry and Molecular Biology, Penn State Hershey College of Medicine, PA 17033, USA.
Biochem Biophys Res Commun. 2012 Nov 23;428(3):333-8. doi: 10.1016/j.bbrc.2012.10.047. Epub 2012 Oct 15.
km23-1 was originally identified as a TGFß receptor-interacting protein that plays an important role in TGFß signaling. Moreover, km23-1 is actually part of an ancient superfamily of NTPase-regulatory proteins, widely represented in archaea and bacteria. To further elucidate the function of km23-1, we identified novel protein interacting partners for km23-1 by using tandem affinity purification (TAP) and tandem mass spectrometry (MS). Here we show that km23-1 interacted with a class of proteins involved in actin-based cell motility and modulation of the actin cytoskeleton. We further showed that km23-1 modulates the formation of a highly organized stress fiber network. More significantly, we demonstrated that knockdown (KD) of km23-1 decreased RhoA activation in Mv1Lu epithelial cells. Finally, our results demonstrated for the first time that depletion of km23-1 inhibited cell migration of human colon carcinoma cells (HCCCs) in wound-healing assays. Overall, our findings demonstrate that km23-1 regulates RhoA and motility-associated actin modulating proteins, suggesting that km23-1 may represent a novel target for anti-metastatic therapy.
km23-1 最初被鉴定为 TGFß 受体相互作用蛋白，在 TGFß 信号转导中发挥重要作用。此外，km23-1 实际上是一种古老的 NTPase 调节蛋白超家族的一部分，在古菌和细菌中广泛存在。为了进一步阐明 km23-1 的功能，我们通过串联亲和纯化（TAP）和串联质谱（MS）鉴定了 km23-1 的新的蛋白相互作用伙伴。在这里，我们显示 km23-1 与一类参与肌动蛋白为基础的细胞运动和肌动蛋白细胞骨架调节的蛋白相互作用。我们进一步表明，km23-1 调节高度组织化的应力纤维网络的形成。更重要的是，我们证明了 km23-1 的敲低（KD）降低了 Mv1Lu 上皮细胞中的 RhoA 激活。最后，我们的结果首次证明，在划痕愈合实验中，km23-1 的耗竭抑制了人结肠癌细胞（HCCCs）的迁移。总的来说，我们的研究结果表明，km23-1 调节 RhoA 和与运动相关的肌动蛋白调节蛋白，提示 km23-1 可能成为抗转移治疗的一个新靶点。
