title: A new mode of mitochondrial transport and polarized sorting regulated by Dynein, Milton and Miro.
abstract: Intrinsic cell microtubule (MT) polarity, together with molecular motors and adaptor proteins, determines mitochondrial polarized targeting and MT-dependent transport. In polarized cells, such as neurons, mitochondrial mobility and transport require the regulation of kinesin and dynein by two adaptor proteins, Milton and Miro. Recently, we found that dynein heavy chain 64C (Dhc64C) is the primary motor protein for both anterograde and retrograde transport of mitochondria in the Drosophila bristle. In this study, we show that a molecular lesion in the Dhc64C allele that reduced bristle mitochondrial velocity generated a variant that acts as a 'slow' dynein in an MT-gliding assay, indicating that dynein directly regulates mitochondrial transport. We also showed that in milton-RNAi flies, mitochondrial flux into the bristle shaft, but not velocity, was significantly reduced. Surprisingly, mitochondria retrograde flux, but not net velocity, was significantly decreased in miro-RNAi flies. We thus reveal a new mode of mitochondrial sorting in polarized cell growth, whereby bi-directional mitochondrial transport undertaken exclusively by dynein is regulated by Milton in the anterograde direction and by a Miro-dependent switch to the retrograde direction.
authors.affiliation: Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410500, Israel.
authors.forename: Anna
authors.initials: A
authors.lastname: Melkov
authors.affiliation: Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410500, Israel.
authors.forename: Raju
authors.initials: R
authors.lastname: Baskar
authors.affiliation: Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410500, Israel.
authors.forename: Yehonatan
authors.initials: Y
authors.lastname: Alcalay
authors.affiliation: Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410500, Israel abdu@bgu.ac.il.
authors.forename: Uri
authors.identifier: 0000-0003-1226-0750
authors.initials: U
authors.lastname: Abdu
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001370:Axonal Transport / Q000235:genetics*; D001692:Biological Transport; D016764:Cell Polarity / Q000502:physiology*; D002923:Cilia / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D004398:Dyneins / Q000235:genetics / Q000502:physiology*; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000502:physiology*; D021381:Protein Transport / Q000235:genetics; D011679:Pupa; D020741:rho GTP-Binding Proteins / Q000235:genetics / Q000502:physiology*
chemical_list: C000622407:Dhc64C protein, Drosophila; D029721:Drosophila Proteins; D024101:Mitochondrial Proteins; D009419:Nerve Tissue Proteins; C470348:milt protein, Drosophila; C504427:Miro protein, Drosophila; D004398:Dyneins; D020741:rho GTP-Binding Proteins
keywords: Bristle; Drosophila; Dynein; Milton; Miro; Mitochondria