title: Nanoscale distribution of mitochondrial import receptor Tom20 is adjusted to cellular conditions and exhibits an inner-cellular gradient.
abstract: The translocase of the mitochondrial outer membrane (TOM) complex is the main import pore for nuclear-encoded proteins into mitochondria, yet little is known about its spatial distribution within the outer membrane. Super-resolution stimulated emission depletion microscopy was used to determine quantitatively the nanoscale distribution of Tom20, a subunit of the TOM complex, in more than 1,000 cells. We demonstrate that Tom20 is located in clusters whose nanoscale distribution is finely adjusted to the cellular growth conditions as well as to the specific position of a cell within a microcolony. The density of the clusters correlates to the mitochondrial membrane potential. The distributions of clusters of Tom20 and of Tom22 follow an inner-cellular gradient from the perinuclear to the peripheral mitochondria. We conclude that the nanoscale distribution of the TOM complex is finely adjusted to the cellular conditions, resulting in distribution gradients both within single cells and between adjacent cells.
authors.affiliation: Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
authors.forename: Christian A
authors.initials: CA
authors.lastname: Wurm
authors.forename: Daniel
authors.initials: D
authors.lastname: Neumann
authors.forename: Marcel A
authors.initials: MA
authors.lastname: Lauterbach
authors.forename: Benjamin
authors.initials: B
authors.lastname: Harke
authors.forename: Alexander
authors.initials: A
authors.lastname: Egner
authors.forename: Stefan W
authors.initials: SW
authors.lastname: Hell
authors.forename: Stefan
authors.initials: S
authors.lastname: Jakobs
mesh_terms: D000818:Animals; D002460:Cell Line; D002468:Cell Physiological Phenomena; D026901:Membrane Transport Proteins; D008928:Mitochondria / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins / Q000032:analysis / Q000378:metabolism; D051336:Mitochondrial Membranes / Q000378:metabolism; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins / Q000032:analysis* / Q000378:metabolism; D051381:Rats; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear / Q000032:analysis / Q000378:metabolism*; D014404:Tubulin / Q000032:analysis / Q000378:metabolism
chemical_list: D026901:Membrane Transport Proteins; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; C489998:Tomm20 protein, rat; D014404:Tubulin