Adaptor proteins MiD49 and MiD51 can act independently of Mff and Fis1 in Drp1 recruitment and are specific for mitochondrial fission.
Drp1 (dynamin-related protein 1) is recruited to both mitochondrial and peroxisomal membranes to execute fission. Fis1 and Mff are Drp1 receptor/effector proteins of mitochondria and peroxisomes. Recently, MiD49 and MiD51 were also shown to recruit Drp1 to the mitochondrial surface; however, different reports have ascribed opposing roles in fission and fusion. Here, we show that MiD49 or MiD51 overexpression blocked fission by acting in a dominant-negative manner by sequestering Drp1 specifically at mitochondria, causing unopposed fusion events at mitochondria along with elongation of peroxisomes. Mitochondrial elongation caused by MiD49/51 overexpression required the action of fusion mediators mitofusins 1 and 2. Furthermore, at low level overexpression when MiD49 and MiD51 form discrete foci at mitochondria, mitochondrial fission events still occurred. Unlike Fis1 and Mff, MiD49 and MiD51 were not targeted to the peroxisomal surface, suggesting that they specifically act to facilitate Drp1-directed fission at mitochondria. Moreover, when MiD49 or MiD51 was targeted to the surface of peroxisomes or lysosomes, Drp1 was specifically recruited to these organelles. Moreover, the Drp1 recruitment activity of MiD49/51 appeared stronger than that of Mff or Fis1. We conclude that MiD49 and MiD51 can act independently of Mff and Fis1 in Drp1 recruitment and suggest that they provide specificity to the division of mitochondria.
Department of Biochemistry, La Trobe Institute for Molecular Science; ARC Centre of Excellence for Coherent X-ray Science, La Trobe University, Melbourne, Victoria 3086.
Catherine S
CS
Palmer
Department of Biochemistry, La Trobe Institute for Molecular Science; ARC Centre of Excellence for Coherent X-ray Science, La Trobe University, Melbourne, Victoria 3086.
Kirstin D
KD
Elgass
Institute for Molecular Bioscience and Centre for Microscopy and Microanalysis, The University of Queensland, St. Lucia, Queensland 4072, Australia.
Robert G
RG
Parton
Department of Biochemistry, La Trobe Institute for Molecular Science.
Laura D
LD
Osellame
Department of Biochemistry, La Trobe Institute for Molecular Science; ARC Centre of Excellence for Coherent X-ray Science, La Trobe University, Melbourne, Victoria 3086.
Diana
D
Stojanovski
Department of Biochemistry, La Trobe Institute for Molecular Science; ARC Centre of Excellence for Coherent X-ray Science, La Trobe University, Melbourne, Victoria 3086. Electronic address: m.ryan@latrobe.edu.au.
Michael T
MT
Ryan
D000818:Animals; D034281:Dynamins / Q000235:genetics / Q000378:metabolism*; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008247:Lysosomes / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism*; D063154:Mitochondrial Dynamics / Q000502:physiology*; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D010445:Peptide Elongation Factors / Q000235:genetics / Q000378:metabolism*; D020675:Peroxisomes / Q000235:genetics / Q000378:metabolism
C476525:FIS1 protein, human; C561064:FIS1 protein, mouse; C561316:MIEF1 protein, human; D008565:Membrane Proteins; C533267:Mff protein, human; D008869:Microtubule-Associated Proteins; D024101:Mitochondrial Proteins; D010445:Peptide Elongation Factors; D020558:GTP Phosphohydrolases; C110768:DNM1L protein, human; C486391:Dnm1l protein, mouse; D034281:Dynamins
Cell Biology; Confocal Microscopy; Drp1; Fission; Mammal; MiD49; MiD51; Mitochondria; Morphology; Peroxisomes