bims-mitpro 2026-01-18 papers

Issue of 2026–01–18
two papers selected by
Andreas Kohler, Umeå University

Cell Mol Life Sci. 2026 Jan 12.

A central role for PINK1 in governing local mitochondrial biogenesis and degradation in neurons.

Neurons have adapted the transport and positioning of mitochondria to fit their extended shape and high energy needs. To sustain mitochondrial function, neurons developed systems that allow local biogenesis and adaption to locally regulate mitochondrial form and function. Likewise, fine-tuned degradative systems are required to protect the neurons from mitochondrial dysfunction. Throughout both domains of mitostasis, the local synthesis of the mitochondrial damage-induced kinase PINK1 emerges as a central player. Along with other nuclear encoded mitochondrial proteins, its mRNA associates with mitochondria to sustain mitochondrial function locally. It also regulates mitochondrial degradation, via regulation of proteases, the generation of mitochondria-derived vesicles and mitophagy. In this review, we provide a general overview of the mechanisms governing mitochondrial health in neurons, with a special focus on the role of PINK1 in this endeavor.

Keywords: Local translation; Mitochondrial proteases; Mitophagy; mRNA transport

DOI: https://doi.org/10.1007/s00018-025-06054-4

EMBO Rep. 2026 Jan 13.

Mitochondrial fission during mitophagy requires both inner and outer mitofissins.

Kentaro Furukawa, Tatsuro Maruyama, Yuji Sakai, Shun-Ichi Yamashita, Keiichi Inoue, Tomoyuki Fukuda, Nobuo N Noda, Tomotake Kanki.

Mitophagy maintains mitochondrial homeostasis through the selective degradation of damaged or excess mitochondria. Recently, we identified mitofissin/Atg44, a mitochondrial intermembrane space-resident fission factor, which directly acts on lipid membranes and drives mitochondrial fission required for mitophagy in yeast. However, it remains unclear whether mitofissin is sufficient for mitophagy-associated mitochondrial fission and whether other factors act from outside mitochondria. Here, we identify a mitochondrial outer membrane-resident mitofissin-like microprotein required for mitophagy, and we name it mitofissin 2/Mfi2 based on the following results. Overexpression of an N-terminal Atg44-like region of Mfi2 induces mitochondrial fragmentation and partially restores mitophagy in atg44Δ cells. Mfi2 binds to lipid membranes and mediates membrane fission in a cardiolipin-dependent manner in vitro, demonstrating its intrinsic mitofissin activity. Coarse-grained molecular dynamics simulations further support the stable interaction of Mfi2 with cardiolipin-containing bilayers. Genetic analyses reveal that Mfi2 and the dynamin-related protein Dnm1 independently facilitate mitochondrial fission during mitophagy. Thus, Atg44 and Mfi2, two mitofissins with distinct localizations, are required for mitophagy-associated mitochondrial fission.

Keywords: Atg44; Mfi2; Mitochondrial Fission; Mitofissin; Mitophagy

DOI: https://doi.org/10.1038/s44319-025-00689-x