Department of Biochemistry, Keio University School of Medicine, Tokyo 160-8582, Japan.
1] Department of Biochemistry, Keio University School of Medicine, Tokyo 160-8582, Japan [2] Japan Science and Technology Agency (JST), Exploratory Research for Advanced Technology (ERATO), Suematsu Gas Biology Project, Tokyo 160-8582, Japan.
Nat Commun. 2014 Mar 17;5:3480. doi: 10.1038/ncomms4480.
Haem oxygenase (HO)-1/carbon monoxide (CO) protects cancer cells from oxidative stress, but the gas-responsive signalling mechanisms remain unknown. Here we show using metabolomics that CO-sensitive methylation of PFKFB3, an enzyme producing fructose 2,6-bisphosphate (F-2,6-BP), serves as a switch to activate phosphofructokinase-1, a rate-limiting glycolytic enzyme. In human leukaemia U937 cells, PFKFB3 is asymmetrically di-methylated at R131 and R134 through modification by protein arginine methyltransferase 1. HO-1 induction or CO results in reduced methylation of PFKFB3 in varied cancer cells to suppress F-2,6-BP, shifting glucose utilization from glycolysis toward the pentose phosphate pathway. Loss of PFKFB3 methylation depends on the inhibitory effects of CO on haem-containing cystathionine β-synthase (CBS). CBS modulates remethylation metabolism, and increases NADPH to supply reduced glutathione, protecting cells from oxidative stress and anti-cancer reagents. Once the methylation of PFKFB3 is reduced, the protein undergoes polyubiquitination and is degraded in the proteasome. These results suggest that the CO/CBS-dependent regulation of PFKFB3 methylation determines directional glucose utilization to ensure resistance against oxidative stress for cancer cell survival.
血红素加氧酶 (HO)-1/一氧化碳 (CO) 可保护癌细胞免受氧化应激，但气体响应的信号机制仍不清楚。在这里，我们使用代谢组学表明，PFKFB3 的 CO 敏感甲基化作为一种开关，可激活磷酸果糖激酶-1（PFK-1），PFKFB3 是产生果糖 2,6-二磷酸（F-2,6-BP）的酶。在人类白血病 U937 细胞中，PFKFB3 通过蛋白质精氨酸甲基转移酶 1 的修饰，在 R131 和 R134 处不对称地二甲基化。HO-1 诱导或 CO 导致各种癌细胞中 PFKFB3 的甲基化减少，从而抑制 F-2,6-BP，使葡萄糖利用从糖酵解转向戊糖磷酸途径。PFKFB3 甲基化的丧失取决于 CO 对含血红素的胱硫醚 β-合酶 (CBS) 的抑制作用。CBS 调节再甲基化代谢，增加 NADPH 以供应还原型谷胱甘肽，从而保护细胞免受氧化应激和抗癌试剂的影响。一旦 PFKFB3 的甲基化减少，该蛋白就会发生多泛素化并在蛋白酶体中降解。这些结果表明，CO/CBS 依赖性 PFKFB3 甲基化调节决定了葡萄糖的定向利用，以确保癌细胞生存对氧化应激的抵抗力。
