Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH.
J Cell Biol. 2020 Dec 7;219(12). doi: 10.1083/jcb.202006151.
Reversible lysine acetylation of nuclear proteins such as histones is a long-established important regulatory mechanism for chromatin remodeling and transcription. In the cytoplasm, acetylation of a number of cytoskeletal proteins, including tubulin, cortactin, and the formin mDia2, regulates both cytoskeletal assembly and stability. More recently, acetylation of actin itself was revealed to regulate cytoplasmic actin polymerization through the formin INF2, with downstream effects on ER-to-mitochondrial calcium transfer, mitochondrial fission, and vesicle transport. This finding raises the possibility that actin acetylation, along with other post-translational modifications to actin, might constitute an "actin code," similar to the "histone code" or "tubulin code," controlling functional shifts to these central cellular proteins. Given the multiple roles of actin in nuclear functions, its modifications might also have important roles in gene expression.
核蛋白（如组蛋白）赖氨酸可逆乙酰化是染色质重塑和转录的长期确立的重要调控机制。在细胞质中，包括微管蛋白、皮质蛋白和形成因子 mDia2 在内的许多细胞骨架蛋白的乙酰化调节细胞骨架的组装和稳定性。最近，肌动蛋白自身的乙酰化被发现通过形成因子 INF2 调节细胞质肌动蛋白聚合，从而对 ER 到线粒体的钙转移、线粒体裂变和囊泡运输产生下游影响。这一发现提出了一种可能性，即肌动蛋白乙酰化以及肌动蛋白的其他翻译后修饰可能构成一种“肌动蛋白密码”，类似于“组蛋白密码”或“微管蛋白密码”，控制这些核心细胞蛋白的功能转变。鉴于肌动蛋白在核功能中的多种作用，其修饰也可能在基因表达中发挥重要作用。
