{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,4]],"date-time":"2026-11-04T13:07:57Z","timestamp":1793797677890,"version":"4.6.1"},"reference-count":0,"publisher":"National Academy of Sciences","issue":"21","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[1992,11]]},"abstract":"<jats:p>Proteolytic cleavage of the protective antigen (PA) protein of anthrax toxin at residues 164-167 is necessary for toxic activity. Cleavage by a cellular protease at this sequence, Arg-Lys-Lys-Arg, normally follows binding of PA to a cell surface receptor. We attempted to identify this protease by determining its sequence specificity and catalytic properties. Semi-random cassette mutagenesis was used to generate mutants with replacements of residues 164-167 by Arg, Lys, Ser, or Asn. Analysis of 19 mutant proteins suggested that lethal factor-dependent toxicity required the sequence Arg-Xaa-Xaa-Arg. Based on these data, three additional mutants were constructed with the sequences Ala-Lys-Lys-Arg, Arg-Lys-Lys-Ala, and Arg-Ala-Ala-Arg. Of these mutant proteins, Arg-Ala-Ala-Arg was toxic, confirming that the cellular protease can recognize the sequence Arg-Xaa-Xaa-Arg. The mutant containing the sequence Ala-Lys-Lys-Arg was also toxic but required &gt; 13 times more protein to produce equivalent toxicity. This sequence specificity is similar to that of the ubiquitous subtilisin-like protease furin, which is involved in processing of precursors of certain receptors and growth factors. Therefore we tested whether a recombinant soluble furin would cleave PA. This furin derivative efficiently cleaved native PA and the Arg-Ala-Ala-Arg mutant but not the nontoxic PA mutants. In addition, previously identified inhibitors of furin blocked cleavage of receptor-bound PA. These data imply that furin is the cellular protease that activates PA, and that nearly all cell types contain at least a small amount of furin exposed on their cell surface.<\/jats:p>","DOI":"10.1073\/pnas.89.21.10277","type":"journal-article","created":{"date-parts":[[2006,5,31]],"date-time":"2006-05-31T08:11:21Z","timestamp":1149063081000},"page":"10277-10281","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":382,"title":["Anthrax toxin protective antigen is activated by a cell surface protease with the sequence specificity and catalytic properties of furin."],"prefix":"10.1073","volume":"89","author":[{"given":"K R","family":"Klimpel","sequence":"first","affiliation":[{"name":"Laboratory of Microbial Ecology, National Institute of Dental Research, National Institutes of Health, Bethesda, MD 20892."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S S","family":"Molloy","sequence":"additional","affiliation":[{"name":"Laboratory of Microbial Ecology, National Institute of Dental Research, National Institutes of Health, Bethesda, MD 20892."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"G","family":"Thomas","sequence":"additional","affiliation":[{"name":"Laboratory of Microbial Ecology, National Institute of Dental Research, National Institutes of Health, Bethesda, MD 20892."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S H","family":"Leppla","sequence":"additional","affiliation":[{"name":"Laboratory of Microbial Ecology, National Institute of Dental Research, National Institutes of Health, Bethesda, MD 20892."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[1992,11]]},"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.89.21.10277","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,13]],"date-time":"2022-04-13T13:48:58Z","timestamp":1649857738000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.89.21.10277"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1992,11]]},"references-count":0,"journal-issue":{"issue":"21","published-print":{"date-parts":[[1992,11]]}},"alternative-id":["10.1073\/pnas.89.21.10277"],"URL":"https:\/\/doi.org\/10.1073\/pnas.89.21.10277","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[1992,11]]},"assertion":[{"value":"1992-11-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}