Mitochondrial Translation Occurs Preferentially in the Peri-Nuclear Mitochondrial Network of Cultured Human Cells

Biology

Rolando Berlinguer-Palmini¹  Fiona McFarlane²  Elisabeta-Ana Savu²  Caroline Hewison²  Matthew Zorkau³  Robert N. Lightowlers³  Zofia M. Chrzanowska-Lightowlers³  Christin A. Albus³ 

[1] Bioimaging Unit, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK;School of Biomedical, Nutritional, and Sport Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK;Wellcome Centre for Mitochondrial Research, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK;

关键词: mitochondria;    mammalian;    protein synthesis;    heterogeneity;    co-localisation;    peri-nuclear;   

DOI  :  10.3390/biology10101050

来源: DOAJ

【 摘 要 】

Human mitochondria are highly dynamic organelles, fusing and budding to maintain reticular networks throughout many cell types. Although extending to the extremities of the cell, the majority of the network is concentrated around the nucleus in most of the commonly cultured cell lines. This organelle harbours its own genome, mtDNA, with a different gene content to the nucleus, but the expression of which is critical for maintaining oxidative phosphorylation. Recent advances in click chemistry have allowed us to visualise sites of mitochondrial protein synthesis in intact cultured cells. We show that the majority of translation occurs in the peri-nuclear region of the network. Further analysis reveals that whilst there is a slight peri-nuclear enrichment in the levels of mitoribosomal protein and mitochondrial rRNA, it is not sufficient to explain this substantial heterogeneity in the distribution of translation. Finally, we also show that in contrast, a mitochondrial mRNA does not show such a distinct gradient in distribution. These data suggest that the relative lack of translation in the peripheral mitochondrial network is not due to an absence of mitoribosomes or an insufficient supply of the mt-mRNA transcripts.

【 授权许可】

Unknown