Myo19 is an outer mitochondrial membrane motor and effector of starvation-induced filopodia

J Cell Sci. 2016 Feb 1;129(3):543-56. doi: 10.1242/jcs.175349. Epub 2015 Dec 11.

Abstract

Mitochondria respond to environmental cues and stress conditions. Additionally, the disruption of the mitochondrial network dynamics and its distribution is implicated in a variety of neurodegenerative diseases. Here, we reveal a new function for Myo19 in mitochondrial dynamics and localization during the cellular response to glucose starvation. Ectopically expressed Myo19 localized with mitochondria to the tips of starvation-induced filopodia. Corollary to this, RNA interference (RNAi)-mediated knockdown of Myo19 diminished filopodia formation without evident effects on the mitochondrial network. We analyzed the Myo19-mitochondria interaction, and demonstrated that Myo19 is uniquely anchored to the outer mitochondrial membrane (OMM) through a 30-45-residue motif, indicating that Myo19 is a stably attached OMM molecular motor. Our work reveals a new function for Myo19 in mitochondrial positioning under stress.

Keywords: Filopodia; Mitochondria; Myosin 19.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • HEK293 Cells
  • Humans
  • Mitochondria / metabolism*
  • Mitochondrial Dynamics / physiology*
  • Mitochondrial Membranes / metabolism*
  • Molecular Motor Proteins / metabolism*
  • Myosins / metabolism*
  • Pseudopodia / metabolism*
  • RNA Interference / physiology
  • Starvation / metabolism*

Substances

  • Molecular Motor Proteins
  • Myo19 protein, human
  • Myosins