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Dolenc I, Štefe I, Turk D, Taler-Verčič A, Turk B, Turk V, Stoka V. Human cathepsin X/Z is a biologically active homodimer. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2020; 1869:140567. [PMID: 33227497 DOI: 10.1016/j.bbapap.2020.140567] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/12/2020] [Accepted: 11/16/2020] [Indexed: 12/15/2022]
Abstract
Human cathepsin X belongs to the cathepsin family of 11 lysosomal cysteine proteases. We expressed recombinant procathepsin X in Pichia pastoris in vitro and cleaved it into its active mature form using aspartic cathepsin E. We found, using size exclusion chromatography, X-ray crystallography, and small-angle X-ray scattering, that cathepsin X is a biologically active homodimer with a molecular weight of ~53 kDa. The novel finding that cathepsin X is a dimeric protein opens new horizons in the understanding of its function and the underlying pathophysiological mechanisms of various diseases including neurodegenerative disorders in humans.
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Affiliation(s)
- Iztok Dolenc
- Department of Biochemistry and Molecular and Structural Biology, J. Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia.
| | - Ivica Štefe
- Department of Biochemistry and Molecular and Structural Biology, J. Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Dušan Turk
- Department of Biochemistry and Molecular and Structural Biology, J. Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia; Centre of Excellence for Integrated Approaches in Chemistry and Biology of Proteins, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Ajda Taler-Verčič
- Department of Biochemistry and Molecular and Structural Biology, J. Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Boris Turk
- Department of Biochemistry and Molecular and Structural Biology, J. Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Vito Turk
- Department of Biochemistry and Molecular and Structural Biology, J. Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Jamova 39, SI-1000 Ljubljana, Slovenia.
| | - Veronika Stoka
- Department of Biochemistry and Molecular and Structural Biology, J. Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia.
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Sachdeva K, Sundaramurthy V. The Interplay of Host Lysosomes and Intracellular Pathogens. Front Cell Infect Microbiol 2020; 10:595502. [PMID: 33330138 PMCID: PMC7714789 DOI: 10.3389/fcimb.2020.595502] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 10/22/2020] [Indexed: 12/20/2022] Open
Abstract
Lysosomes are an integral part of the intracellular defense system against microbes. Lysosomal homeostasis in the host is adaptable and responds to conditions such as infection or nutritional deprivation. Pathogens such as Mycobacterium tuberculosis (Mtb) and Salmonella avoid lysosomal targeting by actively manipulating the host vesicular trafficking and reside in a vacuole altered from the default lysosomal trafficking. In this review, the mechanisms by which the respective pathogen containing vacuoles (PCVs) intersect with lysosomal trafficking pathways and maintain their distinctness are discussed. Despite such active inhibition of lysosomal targeting, emerging literature shows that different pathogens or pathogen derived products exhibit a global influence on the host lysosomal system. Pathogen mediated lysosomal enrichment promotes the trafficking of a sub-set of pathogens to lysosomes, indicating heterogeneity in the host-pathogen encounter. This review integrates recent advancements on the global lysosomal alterations upon infections and the host protective role of the lysosomes against these pathogens. The review also briefly discusses the heterogeneity in the lysosomal targeting of these pathogens and the possible mechanisms and consequences.
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Markmann S, Krambeck S, Hughes CJ, Mirzaian M, Aerts JMFG, Saftig P, Schweizer M, Vissers JPC, Braulke T, Damme M. Quantitative Proteome Analysis of Mouse Liver Lysosomes Provides Evidence for Mannose 6-phosphate-independent Targeting Mechanisms of Acid Hydrolases in Mucolipidosis II. Mol Cell Proteomics 2017; 16:438-450. [PMID: 28062798 DOI: 10.1074/mcp.m116.063636] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 12/24/2016] [Indexed: 01/01/2023] Open
Abstract
The efficient receptor-mediated targeting of soluble lysosomal proteins to lysosomes requires the modification with mannose 6-phosphate (M6P) residues. Although the absence of M6P results in misrouting and hypersecretion of lysosomal enzymes in many cells, normal levels of lysosomal enzymes have been reported in liver of patients lacking the M6P-generating phosphotransferase (PT). The identity of lysosomal proteins depending on M6P has not yet been comprehensively analyzed. In this study we purified lysosomes from liver of PT-defective mice and 67 known soluble lysosomal proteins were identified that illustrated quantitative changes using an ion mobility-assisted data-independent label-free LC-MS approach. After validation of various differentially expressed lysosomal components by Western blotting and enzyme activity assays, the data revealed a small number of lysosomal proteins depending on M6P, including neuraminidase 1, cathepsin F, Npc2, and cathepsin L, whereas the majority reach lysosomes by alternative pathways. These data were compared with findings on cultured hepatocytes and liver sinusoid endothelial cells isolated from the liver of wild-type and PT-defective mice. Our findings show that the relative expression, targeting efficiency and lysosomal localization of lysosomal proteins tested in cultured hepatic cells resemble their proportion in isolated liver lysosomes. Hypersecretion of newly synthesized nonphosphorylated lysosomal proteins suggest that secretion-recapture mechanisms contribute to maintain major lysosomal functions in liver.
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Affiliation(s)
- Sandra Markmann
- From the ‡Department of Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,§Waters Corporation, Wilmslow, SK9 4AX, United Kingdom
| | - Svenja Krambeck
- From the ‡Department of Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,§Waters Corporation, Wilmslow, SK9 4AX, United Kingdom
| | | | - Mina Mirzaian
- ¶Department of Medical Biochemistry, Leiden Institute of Chemistry, Leiden University, Leiden, 2333 CC, The Netherlands
| | - Johannes M F G Aerts
- ¶Department of Medical Biochemistry, Leiden Institute of Chemistry, Leiden University, Leiden, 2333 CC, The Netherlands
| | - Paul Saftig
- ‖Institut für Biochemie, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - Michaela Schweizer
- **Morphology Unit, Center for Molecular Neurobiology ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Thomas Braulke
- From the ‡Department of Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany;
| | - Markus Damme
- ‖Institut für Biochemie, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany;
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Abstract
Pulse-chase methods offer powerful tools for following the evolution of a biological system over time, but are usually limited to ensemble measurements of the average behavior of very large numbers of cells. Here we describe three methods ranging from a true pulse-chase, through selective regional photoactivation, to pharmacological induction of an altered protein state, which can be applied to time-dependent studies at the single-cell level. These methods are exemplified by experimental protocols to follow region-selective nuclear envelope targeting of nascent phospholipids, a nascent nuclear lamin protein (lamin B1), and an immature lamin precursor (prelamin A).
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