Mitochondrial fission 1 protein (FIS1)

Mitochondrial fission 1 protein (FIS1) is a small integral membrane protein (~16 kDa) anchored to the outer mitochondrial membrane through a transmembrane domain at its C-terminus. Its cytosolic domain contains several tetratricopeptide repeats (TPR)-like motifs, implicated in protein-protein interactions. FIS1 participates in the critical process of mitochondrial fission by recruiting and regulating the activity of dynamin-related protein 1 (DRP1), either directly or via adaptor molecules. This role is essential for maintaining healthy mitochondrial distribution, morphology, and function, adapting organelle dynamics to metabolic, apoptotic, and cell cycle demands. FIS1 also forms part of the ARCosome complex at mitochondria-ER contact sites, promoting calcium overload and apoptotic signaling. Aberrations in FIS1 function are associated with mitochondrial dysfunction, which plays a role in cancer, neurodegenerative disorders, and metabolic diseases. While essential for cell survival and adaptation, dysregulation of FIS1 can trigger excessive mitochondrial fragmentation, apoptosis, or senescence, warranting caution for therapeutic interventions[1][2][3][5].

Other names

FIS1TTC11CGI-135hFis1TPR repeat protein 11Mitochondrial fission moleculeH_NH0132A01.6

Indirect modulation of mitochondrial fission via interference with FIS1-DRP1 interaction or ARCosome formation Apoptosis induction (cell death signaling through mitochondrial fragmentation and cytochrome c release)[1][3]