<p>Mitochondrial fission protein 1 (FIS1) is present in the cytoplasm and can be transported to the outer mitochondrial membrane. It can interact with DRP1 (Dynamin-Related Protein 1) to mediate mitochondrial fission and fusion, and most of the studies on FIS1 have centered on FIS1-DRP1 mitochondrial fission. However, more and more studies are now showing that FIS1 is not only involved in mitochondrial fission, but also plays a role in mitophagy, peroxisomal dynamics, and lysosomes. Post-translational modification (PTM) of proteins enables proteins to perform distinct functions and exhibit diverse properties, thereby creating multiple possibilities for many proteins. The post-translational modification of FIS1 protein is associated with the occurrence of many diseases. Environmental pollution has become a serious public health problem that affects people's health. The role of FIS1 in human health caused by environmental pollutants is worth in-depth study and exploration.</p> Graphical Abstract <p>FIS1 can be involved in the occurrence of various diseases through a variety of post-translational modifications. FIS1 can alter its own protein properties through lactylation, SUMOylation, phosphorylation, ubiquitination, and acetylation modifications, thereby affecting the function of FIS1 in mitochondria and participating in various diseases as well as the damage of pollutants to the human body.</p> <p>Graphical Headlights</p> <p>1. FIS1 plays an important role in mitochondrial homeostasis.</p> <p>2. FIS1 alters its own protein properties through lactylation, SUMOylation, phosphorylation, ubiquitination, and acetylation modifications.</p> <p>3. The post-translational modification of FIS1 protein is associated with the occurrence of diseases.</p> <p>4. FIS1 is also one of the target proteins affected by environmental pollutants.</p> <p></p>