title: Loss of Yme1L perturbates mitochondrial dynamics.
abstract: Yme1L is an AAA protease that is embedded in the mitochondrial inner membrane with its catalytic domain facing the mitochondrial inner-membrane space. However, how Yme1L regulates mammalian mitochondrial function is still obscure. We find that endogenous Yme1L locates at punctate structures of mitochondria, and that loss of Yme1L in mouse embryonic fibroblast (MEF) cells results in mitochondrial fragmentation and leads to significant increased 'kiss-and-run' type of mitochondrial fusion; however, Yme1L knockdown (shYme1L (short hairpin-mediated RNA interference of Yme1L)) cells still remain normal mitochondrial fusion although shYme1L mitochondria have a little bit less fusion and fission rates, and the shYme1L-induced fragmentation is due to a little bit more mitochondrial fission than fusion in cells. Furthermore, shYme1L-induced mitochondrial fragmentation is independent on optic atrophy 1 (OPA1) S1 or S2 processing, and shYme1L results in the stabilization of OPA1 long form (L-OPA1); in addition, the exogenous expression of OPA1 or L-OPA1 facilitates the shYme1L-induced mitochondrial fragmentation, thus this fragmentation induced by shYme1L appears to be associated with L-OPA1's stability. ShYme1L also causes a slight increase of mitochondrial dynamics proteins of 49 kDa and mitochondrial fission factor (Mff), which recruit mitochondrial key fission factor dynamin-related protein 1 (Drp1) into mitochondria in MEF cells, and loss of Drp1 or Mff inhibits the shYme1L-induced mitochondrial fragmentation. In addition, there is interaction between SLP-2 with Yme1L and shYme1L cells retain stress-induced mitochondrial hyperfusion. Taken together, our results clarify how Yme1L regulates mitochondrial morphology.
authors.affiliation: College of Life Sciences, Wuhan University, Hubei 430072, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Ruan
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.forename: K
authors.initials: K
authors.lastname: Zhang
authors.forename: F
authors.initials: F
authors.lastname: Jian
authors.forename: J
authors.initials: J
authors.lastname: Tang
authors.forename: Z
authors.initials: Z
authors.lastname: Song
mesh_terms: D000074183:ATPases Associated with Diverse Cellular Activities; D002460:Cell Line; D034281:Dynamins; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D047468:Immunoprecipitation; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008666:Metalloendopeptidases / Q000235:genetics / Q000378:metabolism*; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D063154:Mitochondrial Dynamics / Q000235:genetics / Q000502:physiology*; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D029241:Optic Atrophy, Autosomal Dominant / Q000235:genetics / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; C533267:Mff protein, human; D008869:Microtubule-Associated Proteins; D024101:Mitochondrial Proteins; D008666:Metalloendopeptidases; C410807:YME1L1 protein, human; D020558:GTP Phosphohydrolases; D000074183:ATPases Associated with Diverse Cellular Activities; C110768:DNM1L protein, human; D034281:Dynamins