Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada.
Department of Laboratory Medicine, National Institutes of Health, Bethesda, Maryland, USA.
J Biol Chem. 2021 Jan-Jun;296:100478. doi: 10.1016/j.jbc.2021.100478. Epub 2021 Feb 26.
Melanoma is the most aggressive skin malignancy with increasing incidence worldwide. Pannexin1 (PANX1), a member of the pannexin family of channel-forming glycoproteins, regulates cellular processes in melanoma cells including proliferation, migration, and invasion/metastasis. However, the mechanisms responsible for coordinating and regulating PANX1 function remain unclear. Here, we demonstrated a direct interaction between the C-terminal region of PANX1 and the N-terminal portion of β-catenin, a key transcription factor in the Wnt pathway. At the protein level, β-catenin was significantly decreased when PANX1 was either knocked down or inhibited by two PANX1 blockers, Probenecid and Spironolactone. Immunofluorescence imaging showed a disrupted pattern of β-catenin localization at the cell membrane in PANX1-deficient cells, and transcription of several Wnt target genes, including MITF, was suppressed. In addition, a mitochondrial stress test revealed that the metabolism of PANX1-deficient cells was impaired, indicating a role for PANX1 in the regulation of the melanoma cell metabolic profile. Taken together, our data show that PANX1 directly interacts with β-catenin to modulate growth and metabolism in melanoma cells. These findings provide mechanistic insight into PANX1-mediated melanoma progression and may be applicable to other contexts where PANX1 and β-catenin interact as a potential new component of the Wnt signaling pathway.
黑色素瘤是最具侵袭性的皮肤恶性肿瘤,其发病率在全球范围内呈上升趋势。Pannexin1(PANX1)是连接蛋白家族的通道形成糖蛋白的成员,调节黑色素瘤细胞中的细胞过程,包括增殖、迁移和侵袭/转移。然而,负责协调和调节 PANX1 功能的机制仍不清楚。在这里,我们证明了 PANX1 的 C 端区域与 Wnt 通路中的关键转录因子β-连环蛋白的 N 端部分之间存在直接相互作用。在蛋白质水平上,当 PANX1 被敲低或被两种 PANX1 阻滞剂 Probenecid 和 Spironolactone 抑制时,β-连环蛋白的含量显著降低。免疫荧光成像显示,在 PANX1 缺陷细胞中,β-连环蛋白在细胞膜上的定位模式被破坏,几个 Wnt 靶基因的转录,包括 MITF,受到抑制。此外,线粒体应激测试表明,PANX1 缺陷细胞的代谢受损,表明 PANX1 在调节黑色素瘤细胞代谢特征方面发挥作用。总之,我们的数据表明,PANX1 与 β-连环蛋白直接相互作用,调节黑色素瘤细胞的生长和代谢。这些发现为 PANX1 介导的黑色素瘤进展提供了机制上的见解,并可能适用于其他 PANX1 和 β-连环蛋白相互作用的情况,作为 Wnt 信号通路的一个潜在新组成部分。