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Sánchez-Martín P, Olmos PM, Perez-Cruz F. Enhancing Diversity In GANs Via Non-Uniform Sampling. Inf Sci (N Y) 2023. [DOI: 10.1016/j.ins.2023.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
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2
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Sánchez-Martín P, Kriegenburg F, Alves L, Adam J, Elsaesser J, Babic R, Mancilla H, Licheva M, Tascher G, Münch C, Eimer S, Kraft C. ULK1-mediated phosphorylation regulates the conserved role of YKT6 in autophagy. J Cell Sci 2023; 136:jcs260546. [PMID: 36644903 PMCID: PMC10022743 DOI: 10.1242/jcs.260546] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 01/06/2023] [Indexed: 01/17/2023] Open
Abstract
Autophagy is a catabolic process during which cytosolic material is enwrapped in a newly formed double-membrane structure called the autophagosome, and subsequently targeted for degradation in the lytic compartment of the cell. The fusion of autophagosomes with the lytic compartment is a tightly regulated step and involves membrane-bound SNARE proteins. These play a crucial role as they promote lipid mixing and fusion of the opposing membranes. Among the SNARE proteins implicated in autophagy, the essential SNARE protein YKT6 is the only SNARE protein that is evolutionarily conserved from yeast to humans. Here, we show that alterations in YKT6 function, in both mammalian cells and nematodes, produce early and late autophagy defects that result in reduced survival. Moreover, mammalian autophagosomal YKT6 is phospho-regulated by the ULK1 kinase, preventing premature bundling with the lysosomal SNARE proteins and thereby inhibiting autophagosome-lysosome fusion. Together, our findings reveal that timely regulation of the YKT6 phosphorylation status is crucial throughout autophagy progression and cell survival.
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Affiliation(s)
- Pablo Sánchez-Martín
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Franziska Kriegenburg
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
- CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Ludovico Alves
- Department of Structural Cell Biology, Institute for Cell Biology and Neuroscience, Goethe University Frankfurt, 60438 Frankfurt, Germany
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, 60590 Frankfurt, Germany
| | - Julius Adam
- Department of Structural Cell Biology, Institute for Cell Biology and Neuroscience, Goethe University Frankfurt, 60438 Frankfurt, Germany
| | - Jana Elsaesser
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Riccardo Babic
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Hector Mancilla
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Mariya Licheva
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Georg Tascher
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, 60590 Frankfurt, Germany
| | - Christian Münch
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, 60590 Frankfurt, Germany
| | - Stefan Eimer
- Department of Structural Cell Biology, Institute for Cell Biology and Neuroscience, Goethe University Frankfurt, 60438 Frankfurt, Germany
| | - Claudine Kraft
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
- CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
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3
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Walter C, Marada A, Suhm T, Ernsberger R, Muders V, Kücükköse C, Sánchez-Martín P, Hu Z, Aich A, Loroch S, Solari FA, Poveda-Huertes D, Schwierzok A, Pommerening H, Matic S, Brix J, Sickmann A, Kraft C, Dengjel J, Dennerlein S, Brummer T, Vögtle FN, Meisinger C. Global kinome profiling reveals DYRK1A as critical activator of the human mitochondrial import machinery. Nat Commun 2021; 12:4284. [PMID: 34257281 PMCID: PMC8277783 DOI: 10.1038/s41467-021-24426-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 06/15/2021] [Indexed: 11/21/2022] Open
Abstract
The translocase of the outer mitochondrial membrane TOM constitutes the organellar entry gate for nearly all precursor proteins synthesized on cytosolic ribosomes. Thus, TOM presents the ideal target to adjust the mitochondrial proteome upon changing cellular demands. Here, we identify that the import receptor TOM70 is targeted by the kinase DYRK1A and that this modification plays a critical role in the activation of the carrier import pathway. Phosphorylation of TOM70Ser91 by DYRK1A stimulates interaction of TOM70 with the core TOM translocase. This enables transfer of receptor-bound precursors to the translocation pore and initiates their import. Consequently, loss of TOM70Ser91 phosphorylation results in a strong decrease in import capacity of metabolite carriers. Inhibition of DYRK1A impairs mitochondrial structure and function and elicits a protective transcriptional response to maintain a functional import machinery. The DYRK1A-TOM70 axis will enable insights into disease mechanisms caused by dysfunctional DYRK1A, including autism spectrum disorder, microcephaly and Down syndrome.
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Affiliation(s)
- Corvin Walter
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Adinarayana Marada
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Tamara Suhm
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ralf Ernsberger
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Vera Muders
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Cansu Kücükköse
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Pablo Sánchez-Martín
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Zehan Hu
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Abhishek Aich
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany
| | - Stefan Loroch
- Leibniz Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany
| | | | - Daniel Poveda-Huertes
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Alexandra Schwierzok
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Henrike Pommerening
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Stanka Matic
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jan Brix
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Albert Sickmann
- Leibniz Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany
| | - Claudine Kraft
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Jörn Dengjel
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Sven Dennerlein
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Tilman Brummer
- Institute of Molecular Medicine, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- German Cancer Consortium DKTK Partner Site Freiburg, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - F-Nora Vögtle
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
- CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany.
| | - Chris Meisinger
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
- CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
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4
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Barz S, Kriegenburg F, Sánchez-Martín P, Kraft C. Small but mighty: Atg8s and Rabs in membrane dynamics during autophagy. Biochim Biophys Acta Mol Cell Res 2021; 1868:119064. [PMID: 34048862 PMCID: PMC8261831 DOI: 10.1016/j.bbamcr.2021.119064] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 05/04/2021] [Accepted: 05/21/2021] [Indexed: 11/17/2022]
Abstract
Autophagy is a degradative pathway during which autophagosomes are formed that enwrap cytosolic material destined for turnover within the lytic compartment. Autophagosome biogenesis requires controlled lipid and membrane rearrangements to allow the formation of an autophagosomal seed and its subsequent elongation into a fully closed and fusion-competent double membrane vesicle. Different membrane remodeling events are required, which are orchestrated by the distinct autophagy machinery. An important player among these autophagy proteins is the small lipid-modifier Atg8. Atg8 proteins facilitate various aspects of autophagosome formation and serve as a binding platform for autophagy factors. Also Rab GTPases have been implicated in autophagosome biogenesis. As Atg8 proteins interact with several Rab GTPase regulators, they provide a possible link between autophagy progression and Rab GTPase activity. Here, we review central aspects in membrane dynamics during autophagosome biogenesis with a focus on Atg8 proteins and selected Rab GTPases.
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Affiliation(s)
- Saskia Barz
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany; Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, 79104 Freiburg, Germany
| | - Franziska Kriegenburg
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Pablo Sánchez-Martín
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Claudine Kraft
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.
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5
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Barz S, Kriegenburg F, Henning A, Bhattacharya A, Mancilla H, Sánchez-Martín P, Kraft C. Atg1 kinase regulates autophagosome-vacuole fusion by controlling SNARE bundling. EMBO Rep 2020; 21:e51869. [PMID: 33274589 PMCID: PMC7726815 DOI: 10.15252/embr.202051869] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 11/10/2020] [Accepted: 11/11/2020] [Indexed: 12/26/2022] Open
Abstract
Autophagy mediates the degradation of cytoplasmic material. Upon autophagy induction, autophagosomes form a sealed membrane around the cargo and fuse with the lytic compartment to release the cargo for degradation. In order to avoid premature fusion of immature autophagosomal membranes with the lytic compartment, this process needs to be tightly regulated. Several factors mediating autophagosome–vacuole fusion have recently been identified. In budding yeast, autophagosome–vacuole fusion requires the R‐SNARE Ykt6 on the autophagosome, together with the three Q‐SNAREs Vam3, Vam7, and Vti1 on the vacuole. However, how these SNAREs are regulated during the fusion process is poorly understood. In this study, we investigate the regulation of Ykt6. We found that Ykt6 is directly phosphorylated by Atg1 kinase, which keeps this SNARE in an inactive state. Ykt6 phosphorylation prevents SNARE bundling by disrupting its interaction with the vacuolar SNAREs Vam3 and Vti1, thereby preventing premature autophagosome–vacuole fusion. These findings shed new light on the regulation of autophagosome–vacuole fusion and reveal a further step in autophagy controlled by the Atg1 kinase.
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Affiliation(s)
- Saskia Barz
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany.,Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, Germany
| | - Franziska Kriegenburg
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Anna Henning
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Anuradha Bhattacharya
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany.,Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, Germany
| | - Hector Mancilla
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Pablo Sánchez-Martín
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Claudine Kraft
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,CIBSS-Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
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6
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Abstract
The mechanisms of quality control for extracellular proteins are still poorly understood. In this issue, Itakura et al. (2020. J. Cell. Biol.https://doi.org/10.1083/jcb.201911126) show that upon binding to misfolded proteins, the extracellular chaperone clusterin is internalized via the heparan sulfate receptor to undergo lysosomal degradation.
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Affiliation(s)
- Pablo Sánchez-Martín
- Department of Physiology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Masaaki Komatsu
- Department of Physiology, Juntendo University Graduate School of Medicine, Tokyo, Japan
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7
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Sánchez-Martín P, Sou YS, Kageyama S, Koike M, Waguri S, Komatsu M. NBR1-mediated p62-liquid droplets enhance the Keap1-Nrf2 system. EMBO Rep 2020; 21:e48902. [PMID: 31916398 DOI: 10.15252/embr.201948902] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 12/09/2019] [Accepted: 12/10/2019] [Indexed: 01/25/2023] Open
Abstract
p62/SQSTM1 is a multivalent protein that has the ability to cause liquid-liquid phase separation and serves as a receptor protein that participates in cargo isolation during selective autophagy. This protein is also involved in the non-canonical activation of the Keap1-Nrf2 system, a major oxidative stress response pathway. Here, we show a role of neighbor of BRCA1 gene 1 (NBR1), an autophagy receptor structurally similar to p62/SQSTM1, in p62-liquid droplet formation and Keap1-Nrf2 pathway activation. Overexpression of NBR1 blocks selective degradation of p62/SQSTM1 through autophagy and promotes the accumulation and phosphorylation of p62/SQSTM1 in liquid-like bodies, which is required for the activation of Nrf2. NBR1 is induced in response to oxidative stress, which triggers p62-mediated Nrf2 activation. Conversely, loss of Nbr1 suppresses not only the formation of p62/SQSTM1-liquid droplets, but also of p62-dependent Nrf2 activation during oxidative stress. Taken together, our results show that NBR1 mediates p62/SQSTM1-liquid droplet formation to activate the Keap1-Nrf2 pathway.
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Affiliation(s)
- Pablo Sánchez-Martín
- Department of Physiology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Japan
| | - Yu-Shin Sou
- Department of Cell Biology and Neuroscience, Juntendo University Graduate School of Medicine, Bunkyo-ku, Japan
| | - Shun Kageyama
- Department of Physiology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Japan
| | - Masato Koike
- Department of Cell Biology and Neuroscience, Juntendo University Graduate School of Medicine, Bunkyo-ku, Japan
| | - Satoshi Waguri
- Department of Anatomy and Histology, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Masaaki Komatsu
- Department of Physiology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Japan
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8
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Sánchez-Martín P, Komatsu M. Physiological Stress Response by Selective Autophagy. J Mol Biol 2020; 432:53-62. [DOI: 10.1016/j.jmb.2019.06.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 06/05/2019] [Accepted: 06/09/2019] [Indexed: 01/06/2023]
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9
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Abstract
p62 is a stress‐inducible protein able to change among binding partners, cellular localizations and form liquid droplet structures in a context‐dependent manner. This protein is mainly defined as a cargo receptor for selective autophagy, a process that allows the degradation of detrimental and unnecessary components through the lysosome. Besides this role, its ability to interact with multiple binding partners allows p62 to act as a main regulator of the activation of the Nrf2, mTORC1, and NF‐κB signaling pathways, linking p62 to the oxidative defense system, nutrient sensing, and inflammation, respectively. In the present review, we will present the molecular mechanisms behind the control p62 exerts over these pathways, their interconnection and how their deregulation contributes to cancer progression.
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Affiliation(s)
- Pablo Sánchez-Martín
- Department of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Japan
| | - Tetsuya Saito
- Department of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Japan
| | - Masaaki Komatsu
- Department of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Japan.,Department of Physiology, Juntendo University Graduate School of Medicine, Tokyo, Japan
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10
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Abstract
SQSTM1 (also known as p62) is a multifunctional stress-inducible scaffold protein involved in diverse cellular processes. Its functions are tightly regulated through an extensive pattern of post-translational modifications, and include the isolation of cargos degraded by autophagy, induction of the antioxidant response by the Keap1-Nrf2 system, as well as the regulation of endosomal trafficking, apoptosis and inflammation. Accordingly, malfunction of SQSTM1 is associated with a wide range of diseases, including bone and muscle disorders, neurodegenerative and metabolic diseases, and multiple forms of cancer. In this Review, we summarize current knowledge regarding regulation, post-translational modifications and functions of SQSTM1, as well as how they are dysregulated in various pathogenic contexts.
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Affiliation(s)
- Pablo Sánchez-Martín
- Department of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata 951-8510, Japan
| | - Masaaki Komatsu
- Department of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata 951-8510, Japan .,Department of Physiology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
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11
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Lahuerta M, Aguado C, Sánchez-Martín P, Sanz P, Knecht E. Degradation of altered mitochondria by autophagy is impaired in Lafora disease. FEBS J 2018; 285:2071-2090. [PMID: 29645350 DOI: 10.1111/febs.14468] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 03/23/2018] [Accepted: 04/04/2018] [Indexed: 11/27/2022]
Abstract
Lafora disease (LD) is a fatal neurodegenerative disorder caused mostly by mutations in either of two genes encoding laforin and malin. LD is characterized by accumulation of a poorly branched form of glycogen in the cytoplasm of neurons and other cells. We previously reported dysfunctional mitochondria in different LD models. Now, using mitochondrial uncouplers and respiratory chain inhibitors, we have investigated with human fibroblasts a possible alteration in the selective degradation of damaged mitochondria (mitophagy) in LD. By flow cytometry of MitoTracker-labelled cells and measuring the levels of various mitochondrial proteins by western blot, we found in LD fibroblasts a partial impairment in the increased mitochondrial degradation produced by these treatments. In addition, colocalization of mitochondrial and lysosomal markers decreased in LD fibroblasts. All these results are consistent with a partial impairment in the induced autophagic degradation of dysfunctional mitochondria in LD fibroblasts. However, canonical recruitment of Parkin to mitochondria under these conditions remained unaffected in LD fibroblasts, and also in SH-SY5Y cells after malin and laforin overexpression. Neither mitochondrial localization nor protein levels of Bcl-2-like protein 13, another component of the mitophagic machinery that operates under these conditions, were affected in LD fibroblasts. In contrast, although these treatments raised autophagy in both control and LD fibroblasts, this enhanced autophagy was clearly lower in the latter cells. Therefore, the autophagic degradation of altered mitochondria is impaired in LD, which is due to a partial defect in the autophagic response and not in the canonical mitophagy signalling pathways.
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Affiliation(s)
| | - Carmen Aguado
- Centro de Investigación Príncipe Felipe, Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain
| | - Pablo Sánchez-Martín
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain.,Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Pascual Sanz
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain.,Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Erwin Knecht
- Centro de Investigación Príncipe Felipe, Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain
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12
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Tvrdá E, López-Fernández C, Sánchez-Martín P, Gosálvez J. Sperm DNA fragmentation in donors and normozoospermic patients attending for a first spermiogram: Static and dynamic assessment. Andrologia 2018; 50:e12986. [PMID: 29392785 DOI: 10.1111/and.12986] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/09/2018] [Indexed: 12/19/2022] Open
Abstract
Static assessment of sperm DNA Fragmentation (SDF at the time of ejaculation or sperm thawing when cryopreserved) and the dynamic assessment of SDF (SDF assessed after T2 hr, T6 hr and T24 hr of sperm thawing) were used to establish cut-off values associated with sperm donors when compared with closely related normozoospermic patients. Cryopreserved samples from donors revealed SDF levels two times lower in comparison with the patients. Donor sperm DNA exhibited a 2.5 times higher longevity when compared with the patients. Static values of SDF after thawing of approximately 11% identify the donors with a 71% of sensitivity and 84% specificity. With respect to the dynamic assessment, SDF increases of 2.3 per hr during the first 2 hr of incubation identify the donors with 70% of sensitivity and 66% of specificity. Creating the Rate of Combined Damage (RCD) defined as the product of SDF-T0 by the increase in the damage registered during the first 2 hr of incubation (r-SDF-T0-2 ), an index of RCD = 22.2 units has an identification capacity of donors with a 78% sensitivity and 77% specificity. Such cut-off values could be used to characterise donors with high chromatin resistance to damage when meeting the above-established criteria.
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Affiliation(s)
- E Tvrdá
- Department of Animal Physiology, Faculty of Biotechnology and Food Sciences, Slovak University of Agriculture in Nitra, Nitra, Slovakia
| | - C López-Fernández
- Unit of Genetics, Department of Biology, Universidad Autónoma de Madrid, Madrid, Spain
| | - P Sánchez-Martín
- Clinica Ginemed, C/Farmacéutico Murillo Herrera 3, Sevilla, Spain
| | - J Gosálvez
- Unit of Genetics, Department of Biology, Universidad Autónoma de Madrid, Madrid, Spain
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13
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de la Torre J, Sánchez-Martín P, Gosálvez J, Crespo F. Equivalent seminal characteristics in human and stallion at first and second ejaculated fractions. Andrologia 2016; 49. [PMID: 27660115 DOI: 10.1111/and.12708] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/25/2016] [Indexed: 11/28/2022] Open
Abstract
Sperm quality was assessed in normozoospermic human (n = 10) and Spanish breed stallion (n = 10) after sperm fractionation during ejaculation. The first ejaculated fraction was separated from the second. A third sample was reconstituted using equivalent proportion of both fractions (RAW). Fraction 1, Fraction 2 and RAW semen were incubated for 30 min at 37°C to homogenise the impact of iatrogenic damage between both species. Sperm concentration, motility and sperm DNA damage were assessed in each fraction and RAW semen. The results showed two important facts: (i) spermatozoa confined at Fraction 1 exhibit superior parameters than those included at Fraction 2 in both species, and (ii) there is a certain level of concordance between species in the proportion of benefit observed when Fraction 1 is compared to RAW semen. Altogether, these results call into question whether the standard practice of whole ejaculate collection can be considered the best strategy when using male gametes for artificial insemination. In fact, the reconstituted RAW semen exhibits poorer semen characteristics than those found in Fraction 1.
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Affiliation(s)
- J de la Torre
- Departamento de Biología, Universidad Autónoma de Madrid, Madrid, Spain
| | | | - J Gosálvez
- Departamento de Biología, Universidad Autónoma de Madrid, Madrid, Spain
| | - F Crespo
- Departamento de Reproducción, Centro Militar de Cría Caballar (FESCCR, Ministerio de Defensa), Ávila, Spain
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Sánchez-Martín P, Romá-Mateo C, Viana R, Sanz P. Ubiquitin conjugating enzyme E2-N and sequestosome-1 (p62) are components of the ubiquitination process mediated by the malin–laforin E3-ubiquitin ligase complex. Int J Biochem Cell Biol 2015; 69:204-14. [DOI: 10.1016/j.biocel.2015.10.030] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 10/28/2015] [Accepted: 10/30/2015] [Indexed: 11/26/2022]
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