Continuity of Mitochondrial Budding: Insights from BS-C-1 Cells by In Situ Cryo-electron Tomography

Journal Article · 13 January 2025 · Microscopy and Microanalysis

DOI: https://doi.org/10.1093/mam/ozae122 · OSTI ID:2507148

Hu, Judy Z. ^[1]; Qiao, Lijun ^[2]; Zhao, Xianhai  ^[2]; Liu, Chang-Jun  ^[2]; Hu, Guo-Bin  ^[2]

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1. Ward Melville High School, East Setauket, NY (United States); Brookhaven National Laboratory (BNL), Upton, NY (United States)
2. Brookhaven National Laboratory (BNL), Upton, NY (United States)

Mitochondrial division is a fundamental biological process essensial for cellular functionality and vitality. The prevailing hypothesis that dynamin related protein 1 (Drp1) provides principal control in mitochondrial division, in which it also involves the endoplasmic reticulum (ER) and the cytoskeleton, does not account for all the observations. Therefore. the hypothesis may be incomplete. Our previous study in HeLa cells led to a new hypothesis of mitochondrial division by budding. To follow-up our previous study, we employed in situ cryo-electron tomography to visualize mitochondrial budding in the intact healthy monkey kidney cells (BS-C-1 cells). Our findings reaffirm single and multiple mitochondrial budding, consistent with our observations in HeLa cells. Notably, the budding regions vary significantly in diameter and length, which may represent different stages of budding. More interestingly, neither rings nor ring-like structures, nor the wrapping of ER tubes was observed in the budding regions, suggesting mitochondrial budding is independent from Drp1 and ER. Meanwhile, we uncovered direct interactions between mitochondria and large vesicles that are distinct from small mitochondrial-derived vesicles and extracellular mitovesicles. In conclusion, we propose that these interacting vesicles may have mitochondrial origins.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division (CSGB); USDOE Office of Science (SC), Biological and Environmental Research (BER)
• Grant/Contract Number: SC0012704
• OSTI ID: 2507148
• Report Number(s): BNL--227533-2025-JAAM
• Journal Information: Microscopy and Microanalysis, Journal Name: Microscopy and Microanalysis Journal Issue: 1 Vol. 31; ISSN 1431-9276
• Publisher: Microscopy Society of America (MSA)Copyright Statement
• Country of Publication: United States
• Language: English