Internalization of Exogenous Cystatin F Supresses Cysteine Proteases and Induces the Accumulation of Single-chain Cathepsin L by Multiple Mechanisms

Jeff D. Colbert, Stephen P. Matthews, Janko Kos, Colin Watts

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    19 Citations (Scopus)

    Abstract

    Cystatin F is an unusual member of the cystatin family of protease inhibitors, which is made as an inactive dimer and becomes activated by proteolysis in the endo/lysosome pathway of the immune cells that produce it. However a proportion is secreted and can be taken up and activated by other cells. We show here that cystatin F acquired in this way induces a dramatic accumulation of the single-chain form of cathepsin L (CatL). Cystatin F was observed in the same cellular compartments as CatL and was tightly complexed with CatL as determined by co-precipitation studies. The observed accumulation of single-chain CatL was partly due to cystatin F-mediated inhibition of the putative single-chain to two-chain CatL convertase AEP/legumain and partly to general suppression of cathepsin activity. Thus, cystatin F stabilizes CatL leading to the dramatic accumulation of an inactive complex composed either of the single-chain or two-chain form depending on the capacity of cystatin F to inhibit AEP. Cross-transfer of cystatin F from one cell to another may therefore attenuate potentially harmful effects of excessive CatL activity while paradoxically, inducing accumulation of CatL protein. Finally, we confirmed earlier data (Beers, C., Honey, K., Fink, S., Forbush, K., and Rudensky, A. (2003) J. Exp. Med. 197, 169-179) showing a loss of CatL activity, but not of CatL protein, in macrophages activated with IFN gamma. However, we found equivalent loss of CatL activity in wild type and cystatin F-null macrophages suggesting that an inhibitory activity other than cystatin F quenches CatL activity in activated macrophages.

    Original languageEnglish
    Pages (from-to)42082-42090
    Number of pages9
    JournalJournal of Biological Chemistry
    Volume286
    Issue number49
    DOIs
    Publication statusPublished - 9 Dec 2011

    Keywords

    • ASPARAGINYL ENDOPEPTIDASE
    • PROTEINASE-INHIBITOR
    • LYSOSOMAL PROTEASES
    • MAMMALIAN LEGUMAIN
    • INVARIANT CHAIN
    • MACROPHAGES
    • EXPRESSION
    • DISEASE
    • CANCER
    • ROLES

    Cite this

    @article{6eb72d8788144a4996cb7bcc858220de,
    title = "Internalization of Exogenous Cystatin F Supresses Cysteine Proteases and Induces the Accumulation of Single-chain Cathepsin L by Multiple Mechanisms",
    abstract = "Cystatin F is an unusual member of the cystatin family of protease inhibitors, which is made as an inactive dimer and becomes activated by proteolysis in the endo/lysosome pathway of the immune cells that produce it. However a proportion is secreted and can be taken up and activated by other cells. We show here that cystatin F acquired in this way induces a dramatic accumulation of the single-chain form of cathepsin L (CatL). Cystatin F was observed in the same cellular compartments as CatL and was tightly complexed with CatL as determined by co-precipitation studies. The observed accumulation of single-chain CatL was partly due to cystatin F-mediated inhibition of the putative single-chain to two-chain CatL convertase AEP/legumain and partly to general suppression of cathepsin activity. Thus, cystatin F stabilizes CatL leading to the dramatic accumulation of an inactive complex composed either of the single-chain or two-chain form depending on the capacity of cystatin F to inhibit AEP. Cross-transfer of cystatin F from one cell to another may therefore attenuate potentially harmful effects of excessive CatL activity while paradoxically, inducing accumulation of CatL protein. Finally, we confirmed earlier data (Beers, C., Honey, K., Fink, S., Forbush, K., and Rudensky, A. (2003) J. Exp. Med. 197, 169-179) showing a loss of CatL activity, but not of CatL protein, in macrophages activated with IFN gamma. However, we found equivalent loss of CatL activity in wild type and cystatin F-null macrophages suggesting that an inhibitory activity other than cystatin F quenches CatL activity in activated macrophages.",
    keywords = "ASPARAGINYL ENDOPEPTIDASE, PROTEINASE-INHIBITOR, LYSOSOMAL PROTEASES, MAMMALIAN LEGUMAIN, INVARIANT CHAIN, MACROPHAGES, EXPRESSION, DISEASE, CANCER, ROLES",
    author = "Colbert, {Jeff D.} and Matthews, {Stephen P.} and Janko Kos and Colin Watts",
    year = "2011",
    month = "12",
    day = "9",
    doi = "10.1074/jbc.M111.253914",
    language = "English",
    volume = "286",
    pages = "42082--42090",
    journal = "Journal of Biological Chemistry",
    issn = "0021-9258",
    publisher = "American Society for Biochemistry and Molecular Biology",
    number = "49",

    }

    TY - JOUR

    T1 - Internalization of Exogenous Cystatin F Supresses Cysteine Proteases and Induces the Accumulation of Single-chain Cathepsin L by Multiple Mechanisms

    AU - Colbert, Jeff D.

    AU - Matthews, Stephen P.

    AU - Kos, Janko

    AU - Watts, Colin

    PY - 2011/12/9

    Y1 - 2011/12/9

    N2 - Cystatin F is an unusual member of the cystatin family of protease inhibitors, which is made as an inactive dimer and becomes activated by proteolysis in the endo/lysosome pathway of the immune cells that produce it. However a proportion is secreted and can be taken up and activated by other cells. We show here that cystatin F acquired in this way induces a dramatic accumulation of the single-chain form of cathepsin L (CatL). Cystatin F was observed in the same cellular compartments as CatL and was tightly complexed with CatL as determined by co-precipitation studies. The observed accumulation of single-chain CatL was partly due to cystatin F-mediated inhibition of the putative single-chain to two-chain CatL convertase AEP/legumain and partly to general suppression of cathepsin activity. Thus, cystatin F stabilizes CatL leading to the dramatic accumulation of an inactive complex composed either of the single-chain or two-chain form depending on the capacity of cystatin F to inhibit AEP. Cross-transfer of cystatin F from one cell to another may therefore attenuate potentially harmful effects of excessive CatL activity while paradoxically, inducing accumulation of CatL protein. Finally, we confirmed earlier data (Beers, C., Honey, K., Fink, S., Forbush, K., and Rudensky, A. (2003) J. Exp. Med. 197, 169-179) showing a loss of CatL activity, but not of CatL protein, in macrophages activated with IFN gamma. However, we found equivalent loss of CatL activity in wild type and cystatin F-null macrophages suggesting that an inhibitory activity other than cystatin F quenches CatL activity in activated macrophages.

    AB - Cystatin F is an unusual member of the cystatin family of protease inhibitors, which is made as an inactive dimer and becomes activated by proteolysis in the endo/lysosome pathway of the immune cells that produce it. However a proportion is secreted and can be taken up and activated by other cells. We show here that cystatin F acquired in this way induces a dramatic accumulation of the single-chain form of cathepsin L (CatL). Cystatin F was observed in the same cellular compartments as CatL and was tightly complexed with CatL as determined by co-precipitation studies. The observed accumulation of single-chain CatL was partly due to cystatin F-mediated inhibition of the putative single-chain to two-chain CatL convertase AEP/legumain and partly to general suppression of cathepsin activity. Thus, cystatin F stabilizes CatL leading to the dramatic accumulation of an inactive complex composed either of the single-chain or two-chain form depending on the capacity of cystatin F to inhibit AEP. Cross-transfer of cystatin F from one cell to another may therefore attenuate potentially harmful effects of excessive CatL activity while paradoxically, inducing accumulation of CatL protein. Finally, we confirmed earlier data (Beers, C., Honey, K., Fink, S., Forbush, K., and Rudensky, A. (2003) J. Exp. Med. 197, 169-179) showing a loss of CatL activity, but not of CatL protein, in macrophages activated with IFN gamma. However, we found equivalent loss of CatL activity in wild type and cystatin F-null macrophages suggesting that an inhibitory activity other than cystatin F quenches CatL activity in activated macrophages.

    KW - ASPARAGINYL ENDOPEPTIDASE

    KW - PROTEINASE-INHIBITOR

    KW - LYSOSOMAL PROTEASES

    KW - MAMMALIAN LEGUMAIN

    KW - INVARIANT CHAIN

    KW - MACROPHAGES

    KW - EXPRESSION

    KW - DISEASE

    KW - CANCER

    KW - ROLES

    U2 - 10.1074/jbc.M111.253914

    DO - 10.1074/jbc.M111.253914

    M3 - Article

    VL - 286

    SP - 42082

    EP - 42090

    JO - Journal of Biological Chemistry

    JF - Journal of Biological Chemistry

    SN - 0021-9258

    IS - 49

    ER -