title: Mitophagy is primarily due to alternative autophagy and requires the MAPK1 and MAPK14 signaling pathways.
abstract: In cultured cells, not many mitochondria are degraded by mitophagy induced by physiological cellular stress. We observed mitophagy in HeLa cells using a method that relies on the pH-sensitive fluorescent protein Keima. With this approach, we found that mitophagy was barely induced by carbonyl cyanide m-chlorophenyl hydrazone treatment, which is widely used as an inducer of PARK2/Parkin-related mitophagy, whereas a small but modest amount of mitochondria were degraded by mitophagy under conditions of starvation or hypoxia. Mitophagy induced by starvation or hypoxia was marginally suppressed by knockdown of ATG7 and ATG12, or MAP1LC3B, which are essential for conventional macroautophagy. In addition, mitophagy was efficiently induced in Atg5 knockout mouse embryonic fibroblasts. However, knockdown of RAB9A and RAB9B, which are essential for alternative autophagy, but not conventional macroautophagy, severely suppressed mitophagy. Finally, we found that the MAPKs MAPK1/ERK2 and MAPK14/p38 were required for mitophagy. Based on these findings, we conclude that mitophagy in mammalian cells predominantly occurs through an alternative autophagy pathway, requiring the MAPK1 and MAPK14 signaling pathways.
authors.affiliation: a Laboratory of Biosignaling ; Niigata University Graduate School of Medical and Dental Sciences ; Niigata , Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Hirota
authors.forename: Shun-ichi
authors.initials: S
authors.lastname: Yamashita
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kurihara
authors.forename: Xiulian
authors.initials: X
authors.lastname: Jin
authors.forename: Masamune
authors.initials: M
authors.lastname: Aihara
authors.forename: Tetsu
authors.initials: T
authors.lastname: Saigusa
authors.forename: Dongchon
authors.initials: D
authors.lastname: Kang
authors.forename: Tomotake
authors.initials: T
authors.lastname: Kanki
mesh_terms: D000818:Animals; D001343:Autophagy / Q000187:drug effects / Q000502:physiology*; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D008247:Lysosomes / Q000378:metabolism; D051379:Mice; D008928:Mitochondria / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048308:Mitogen-Activated Protein Kinase 14 / Q000378:metabolism*; D063306:Mitophagy / Q000187:drug effects / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*
chemical_list: D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; C535150:MAPK1 protein, human; C535148:Mapk1 protein, mouse; D019950:Mitogen-Activated Protein Kinase 1; D048308:Mitogen-Activated Protein Kinase 14
keywords: 3-MA, 3-methyladenine; ATG, autophagy-related; CCCP, carbonyl cyanide m-chlorophenyl hydrazone; ER, endoplasmic reticulum; FUNDC1, FUN14 Domain Containing 1; Keima; LC3, microtubule-associated protein 1 light chain 3; MAPK, mitogen-activated protein kinase; MEF, mouse embryonic fibroblast; MEK, MAPK-ERK kinase; MKK, MAP kinase kinase; PE, phosphatidylethanolamine; PINK1, PTEN-induced putative kinase protein 1; PTEN, phosphatase and tensin homolog; SQSTM1, sequestosome 1; Tet, tetracycline; alternative autophagy; autophagy; mitochondria; mitogen-activated protein kinase; mitophagy; siRNA, short interfering RNA
references.citation: Hum Mol Genet. 2010 Dec 15;19(24):4861-70
references.pmid: 20871098
references.citation: J Am Chem Soc. 2009 Aug 5;131(30):10356-7
references.pmid: 19722611
references.citation: PLoS One. 2011;6(3):e16746
references.pmid: 21408142
references.citation: Cell Mol Life Sci. 2009 Sep;66(17):2913-32
references.pmid: 19593531
references.citation: Proc Natl Acad Sci U S A. 2010 Mar 16;107(11):5018-23
references.pmid: 20194754
references.citation: J Cell Biol. 1990 Jun;110(6):1923-33
references.pmid: 2351689
references.citation: Nat Rev Mol Cell Biol. 2009 Jul;10(7):458-67
references.pmid: 19491929
references.citation: Nat Cell Biol. 2013 Sep;15(9):1067-78
references.pmid: 23873149
references.citation: Dev Cell. 2009 Jul;17(1):98-109
references.pmid: 19619495
references.citation: J Cell Biol. 2011 May 16;193(4):755-67
references.pmid: 21576396
references.citation: Int J Cell Biol. 2012;2012:189794
references.pmid: 22536246
references.citation: PLoS Biol. 2006 Nov;4(12):e423
references.pmid: 17132049
references.citation: Autophagy. 2010 May;6(4):462-72
references.pmid: 20364102
references.citation: Mol Biol Cell. 2013 Apr;24(8):1153-62
references.pmid: 23427266
references.citation: Nature. 2009 Oct 1;461(7264):654-8
references.pmid: 19794493
references.citation: Nat Cell Biol. 2010 Feb;12(2):119-31
references.pmid: 20098416
references.citation: J Immunol. 2011 May 1;186(9):5313-22
references.pmid: 21421856
references.citation: Cell Host Microbe. 2011 May 19;9(5):376-89
references.pmid: 21575909
references.citation: EMBO J. 2000 Nov 1;19(21):5720-8
references.pmid: 11060023
references.citation: Nature. 2006 Oct 19;443(7113):780-6
references.pmid: 17051204
references.citation: Dev Cell. 2009 Jul;17(1):87-97
references.pmid: 19619494
references.citation: Nat Cell Biol. 2008 May;10(5):602-10
references.pmid: 18391941
references.citation: Nat Cell Biol. 2012 Feb;14(2):177-85
references.pmid: 22267086
references.citation: Proc Natl Acad Sci U S A. 2010 Jan 5;107(1):378-83
references.pmid: 19966284
references.citation: Nat Biotechnol. 2006 May;24(5):577-81
references.pmid: 16648840
references.citation: Genes Dev. 2011 Apr 15;25(8):795-800
references.pmid: 21498569
references.citation: Proc Natl Acad Sci U S A. 2007 Dec 4;104(49):19500-5
references.pmid: 18048346
references.citation: Nature. 2008 Jul 10;454(7201):232-5
references.pmid: 18454133
references.citation: EMBO Rep. 2010 Jan;11(1):45-51
references.pmid: 20010802
references.citation: EMBO Rep. 2013 Dec;14(12):1127-35
references.pmid: 24176932
references.citation: Cell Death Differ. 2009 Jul;16(7):939-46
references.pmid: 19229244
references.citation: Mol Cell Proteomics. 2008 Dec;7(12):2419-28
references.pmid: 18687634
references.citation: PLoS One. 2010;5(4):e10054
references.pmid: 20383334
references.citation: Nature. 2004 Dec 23;432(7020):1032-6
references.pmid: 15525940
references.citation: Rejuvenation Res. 2005 Spring;8(1):3-5
references.pmid: 15798367
references.citation: Antioxid Redox Signal. 2011 May 15;14(10):1919-28
references.pmid: 21126216
references.citation: Proc Natl Acad Sci U S A. 2009 Nov 24;106(47):19860-5
references.pmid: 19910529
references.citation: Autophagy. 2008 Aug;4(6):770-82
references.pmid: 18594198
references.citation: Nature. 2008 Feb 28;451(7182):1069-75
references.pmid: 18305538
references.citation: EMBO J. 2008 Jan 23;27(2):433-46
references.pmid: 18200046
references.citation: Chem Biol. 2011 Aug 26;18(8):1042-52
references.pmid: 21867919
references.citation: Cell Metab. 2012 Nov 7;16(5):613-24
references.pmid: 23140641
references.citation: EMBO Rep. 2013 Sep;14(9):788-94
references.pmid: 23897086
references.citation: Mol Biol Cell. 2011 Sep;22(17):3206-17
references.pmid: 21757540
references.citation: J Cell Biol. 2008 Dec 1;183(5):795-803
references.pmid: 19029340
references.citation: PLoS Biol. 2010 Jan;8(1):e1000298
references.pmid: 20126261
references.citation: J Cell Biol. 2001 Feb 19;152(4):657-68
references.pmid: 11266458
references.citation: Nat Cell Biol. 2010 Sep;12(9):814-22
references.pmid: 20811353
references.citation: Int J Biochem Cell Biol. 2004 Dec;36(12):2503-18
references.pmid: 15325588
references.citation: Nature. 2011 Jan 20;469(7330):323-35
references.pmid: 21248839
references.citation: J Cell Biol. 2010 Apr 19;189(2):211-21
references.pmid: 20404107
references.citation: Autophagy. 2013 Mar;9(3):361-73
references.pmid: 23291478
references.citation: Annu Rev Biochem. 2000;69:303-42
references.pmid: 10966461
references.citation: J Cell Biol. 2010 Dec 27;191(7):1367-80
references.pmid: 21173115