1. Myristoylation-mediated phase separation of EZH2 compartmentalizes STAT3 to promote lung cancer growth
Jie Zhang, Yuanyuan Zeng, Yueping Xing, Xiangrong Li, Lingqin Zhou, Lin Hu, Y Eugene Chin, Meng Wu Cancer Lett. 2021 Sep 28;516:84-98. doi: 10.1016/j.canlet.2021.05.035. Epub 2021 Jun 5.
N-myristoylation is a crucial signaling and pathogenic modification process that confers hydrophobicity to cytosolic proteins. Although different large-scale approaches have been applied, a large proportion of myristoylated proteins remain to be identified. EZH2 is overexpressed in lung cancer cells and exerts oncogenic effects via its intrinsic methyltransferase activity. Using a well-established click chemistry approach, we found that EZH2 can be modified by myristoylation at its N-terminal glycine in lung cancer cells. Hydrophobic interaction is one of the main forces driving or stabilizing liquid-liquid phase separation (LLPS), raising the possibility that myristoylation can modulate LLPS by mediating hydrophobic interactions. Indeed, myristoylation facilitates EZH2 to form phase-separated liquid droplets in lung cancer cells and in vitro. Furthermore, we provide evidence that myristoylation-mediated LLPS of EZH2 compartmentalizes its non-canonical substrate, STAT3, and activates STAT3 signaling, ultimately resulting in accelerated lung cancer cell growth. Thus, targeting EZH2 myristoylation may have significant therapeutic efficacy in the treatment of lung cancer. Altogether, these observations not only extend the list of myristoylated proteins, but also indicate that hydrophobic lipidation may serve as a novel incentive to induce or maintain LLPS.
2. N-myristoylation: from cell biology to translational medicine
Meng Yuan, Zi-Han Song, Mei-Dan Ying, Hong Zhu, Qiao-Jun He, Bo Yang, Ji Cao Acta Pharmacol Sin. 2020 Aug;41(8):1005-1015. doi: 10.1038/s41401-020-0388-4. Epub 2020 Mar 18.
Various lipids and lipid metabolites are bound to and modify the proteins in eukaryotic cells, which are known as 'protein lipidation'. There are four major types of the protein lipidation, i.e. myristoylation, palmitoylation, prenylation, and glycosylphosphatidylinositol anchor. N-myristoylation refers to the attachment of 14-carbon fatty acid myristates to the N-terminal glycine of proteins by N-myristoyltransferases (NMT) and affects their physiology such as plasma targeting, subcellular tracking and localization, thereby influencing the function of proteins. With more novel pathogenic N-myristoylated proteins are identified, the N-myristoylation will attract great attentions in various human diseases including infectious diseases, parasitic diseases, and cancers. In this review, we summarize the current understanding of N-myristoylation in physiological processes and discuss the hitherto implication of crosstalk between N-myristoylation and other protein modification. Furthermore, we mention several well-studied NMT inhibitors mainly in infectious diseases and cancers and generalize the relation of NMT and cancer progression by browsing the clinic database. This review also aims to highlight the further investigation into the dynamic crosstalk of N-myristoylation in physiological processes as well as the potential application of protein N-myristoylation in translational medicine.
R V Rajala, R S Datla, T N Moyana, R Kakkar, S A Carlsen, R K Sharma Mol Cell Biochem. 2000 Jan;204(1-2):135-55. doi: 10.1023/a:1007012622030.
Myristoylation refers to the co-translational addition of a myristoyl group to an amino-terminal glycine residue of a protein by an ubiquitously distributed enzyme myristoyl-CoA:protein N-myristoyltransferase (NMT, EC 22.214.171.124). This review describes the basic enzymology, molecular cloning and regulation of NMT activity in various pathophysiological processes such as colon cancer and diabetes.