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Cheon Y, Yoon S, Lee JH, Kim K, Kim HJ, Hong SW, Yun YR, Shim J, Kim SH, Lu B, Lee M, Lee S. A Novel Interaction between MFN2/Marf and MARK4/PAR-1 Is Implicated in Synaptic Defects and Mitochondrial Dysfunction. eNeuro 2023; 10:ENEURO.0409-22.2023. [PMID: 37550059 PMCID: PMC10444538 DOI: 10.1523/eneuro.0409-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 06/19/2023] [Accepted: 06/21/2023] [Indexed: 08/09/2023] Open
Abstract
As cellular energy powerhouses, mitochondria undergo constant fission and fusion to maintain functional homeostasis. The conserved dynamin-like GTPase, Mitofusin2 (MFN2)/mitochondrial assembly regulatory factor (Marf), plays a role in mitochondrial fusion, mutations of which are implicated in age-related human diseases, including several neurodegenerative disorders. However, the regulation of MFN2/Marf-mediated mitochondrial fusion, as well as the pathologic mechanism of neurodegeneration, is not clearly understood. Here, we identified a novel interaction between MFN2/Marf and microtubule affinity-regulating kinase 4 (MARK4)/PAR-1. In the Drosophila larval neuromuscular junction, muscle-specific overexpression of MFN2/Marf decreased the number of synaptic boutons, and the loss of MARK4/PAR-1 alleviated the synaptic defects of MFN2/Marf overexpression. Downregulation of MARK4/PAR-1 rescued the mitochondrial hyperfusion phenotype caused by MFN2/Marf overexpression in the Drosophila muscles as well as in the cultured cells. In addition, knockdown of MARK4/PAR-1 rescued the respiratory dysfunction of mitochondria induced by MFN2/Marf overexpression in mammalian cells. Together, our results indicate that the interaction between MFN2/Marf and MARK4/PAR-1 is fine-tuned to maintain synaptic integrity and mitochondrial homeostasis, and its dysregulation may be implicated in neurologic pathogenesis.
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Affiliation(s)
- Yeongmi Cheon
- Gwangju Center, Korea Basic Science Institute, Gwangju 61751, Korea
- Laboratory of Molecular Biochemistry, Chonnam National University, Gwangju 61186, Korea
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon 34134, Korea
| | - Sunggyu Yoon
- Gwangju Center, Korea Basic Science Institute, Gwangju 61751, Korea
- Department of Life Science, College of Natural Science, Hanyang University, Seoul 04763, Korea
| | - Jae-Hyuk Lee
- Gwangju Center, Korea Basic Science Institute, Gwangju 61751, Korea
| | - Kiyoung Kim
- Department of Medical Science, Soonchunhyang University, Asan 31538, Korea
| | - Hyung-Jun Kim
- Dementia Research Group, Korea Brain Research Institute, Daegu 41068, Korea
| | - Sung Wook Hong
- Kimchi Functionality Research Group, World Institute of Kimchi, Gwangju 61755, Korea
| | - Ye-Rang Yun
- Kimchi Functionality Research Group, World Institute of Kimchi, Gwangju 61755, Korea
| | - Jiwon Shim
- Department of Life Science, College of Natural Science, Hanyang University, Seoul 04763, Korea
| | - Sung-Hak Kim
- Laboratory of Molecular Biochemistry, Chonnam National University, Gwangju 61186, Korea
| | - Bingwei Lu
- Department of Pathology, Stanford University School of Medicine, Stanford, California 94305
| | - Mihye Lee
- Soonchunhyang Institute of Medi-Bio Science, Soonchunhyang University, Cheonan 31151, Korea
| | - Seongsoo Lee
- Gwangju Center, Korea Basic Science Institute, Gwangju 61751, Korea
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Oba T, Saito T, Asada A, Shimizu S, Iijima KM, Ando K. Microtubule affinity-regulating kinase 4 with an Alzheimer's disease-related mutation promotes tau accumulation and exacerbates neurodegeneration. J Biol Chem 2020; 295:17138-17147. [PMID: 33020179 PMCID: PMC7863894 DOI: 10.1074/jbc.ra120.014420] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 09/19/2020] [Indexed: 12/21/2022] Open
Abstract
Accumulation of the microtubule-associated protein tau is associated with Alzheimer's disease (AD). In AD brain, tau is abnormally phosphorylated at many sites, and phosphorylation at Ser-262 and Ser-356 plays critical roles in tau accumulation and toxicity. Microtubule affinity-regulating kinase 4 (MARK4) phosphorylates tau at those sites, and a double de novo mutation in the linker region of MARK4, ΔG316E317D, is associated with an elevated risk of AD. However, it remains unclear how this mutation affects phosphorylation, aggregation, and accumulation of tau and tau-induced neurodegeneration. Here, we report that MARK4ΔG316E317D increases the abundance of highly phosphorylated, insoluble tau species and exacerbates neurodegeneration via Ser-262/356-dependent and -independent mechanisms. Using transgenic Drosophila expressing human MARK4 (MARK4wt) or a mutant version of MARK4 (MARK4ΔG316E317D), we found that coexpression of MARK4wt and MARK4ΔG316E317D increased total tau levels and enhanced tau-induced neurodegeneration and that MARK4ΔG316E317D had more potent effects than MARK4wt Interestingly, the in vitro kinase activities of MARK4wt and MARK4ΔG316E317D were similar. When tau phosphorylation at Ser-262 and Ser-356 was blocked by alanine substitutions, MARK4wt did not promote tau accumulation or exacerbate neurodegeneration, whereas coexpression of MARK4ΔG316E317D did. Both MARK4wt and MARK4ΔG316E317D increased the levels of oligomeric forms of tau; however, only MARK4ΔG316E317D further increased the detergent insolubility of tau in vivo Together, these findings suggest that MARK4ΔG316E317D increases tau levels and exacerbates tau toxicity via a novel gain-of-function mechanism and that modification in this region of MARK4 may affect disease pathogenesis.
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Affiliation(s)
- Toshiya Oba
- Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan
| | - Taro Saito
- Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan; Department of Biological Sciences, School of Science, Tokyo Metropolitan University, Tokyo, Japan
| | - Akiko Asada
- Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan; Department of Biological Sciences, School of Science, Tokyo Metropolitan University, Tokyo, Japan
| | - Sawako Shimizu
- Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan
| | - Koichi M Iijima
- Department of Alzheimer's Disease Research, National Center for Geriatrics and Gerontology, Obu, Japan; Department of Experimental Gerontology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Kanae Ando
- Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan; Department of Biological Sciences, School of Science, Tokyo Metropolitan University, Tokyo, Japan.
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