title: A hyperstructure approach to mitochondria.
abstract: Several questions in our understanding of mitochondria are unanswered. These include how the ratio of mitochondrial (mt)DNA to mitochondria is maintained, how the accumulation of defective, rapidly replicating mitochondrial DNA is avoided, how the ratio of mitochondria to cells is adjusted to fit cellular needs, and why any proteins are synthesized in mitochondria rather than simply imported. In bacteria, large hyperstructures or assemblies of proteins, mRNA, lipids and ions have been proposed to constitute a level of organization intermediate between macromolecules and whole cells. Here, we suggest how the concept of hyperstructures together with other concepts developed for bacteria such as transcriptional sensing and spontaneous segregation may provide answers to mitochondrial problems. In doing this, we show how the problem of the very existence of mtDNA brings its own solution.
authors.affiliation: Department of Experimental Oncology, European Institute of Oncology, 20141 Milan, Italy.
authors.forename: Mirella
authors.initials: M
authors.lastname: Trinei
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Vannier
authors.forename: Marie
authors.initials: M
authors.lastname: Beurton-Aimar
authors.forename: Vic
authors.initials: V
authors.lastname: Norris
mesh_terms: D004272:DNA, Mitochondrial / Q000737:chemistry / Q000502:physiology*; D008928:Mitochondria / Q000235:genetics / Q000502:physiology*; D008954:Models, Biological; D015388:Organelles / Q000378:metabolism
chemical_list: D004272:DNA, Mitochondrial