Characterization of murine cathepsin W and its role in cell-mediated cytotoxicity.
Cathepsin W is a member of the papain-like family of cysteine proteases. In this report, we have isolated the cDNA for murine CtsW (mCtsW) from a splenocyte library. The deduced 371-amino-acid sequence shares 68% identity with human CtsW and includes the conserved catalytic triad cysteine, histidine, and asparagine found in all members of this family. In addition to the fulllength form of mCtsW, we have isolated an alternatively spliced form of the mRNA that lacks a complete catalytic triad. An S1 nuclease protection assay and a Western blot analysis showed that mCtsW is mainly restricted to the CD8(+) T cell and natural killer cell compartments. In addition, we confirmed that, like its human homologue, mCtsW is localized mainly to the endoplasmic reticulum and its expression is up-regulated upon activation. We also characterized the mCtsW locus using bacterial artificial chromosome clones. The gene consists of 10 coding exons and 9 introns spanning 3.2 kb. To elucidate the physiologic role of this protease, we generated mice deficient in mCtsW. Our data establish that mCtsW is not required for cytotoxic lymphocyte-induced target cell death in vitro. In addition, mCtsW deficiency does not alter the susceptibility of cytotoxic lymphocytes to suicide or fratricide after degranulation. Thus, mCtsW does not have a unique role in target cell apoptosis or cytotoxic cell survival in vitro.
Ondr
Jennifer K
JK
Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Pham
Christine T N
CT
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D019556:COS Cells; D056664:Cathepsin W; D002403:Cathepsins / Q000172:deficiency / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D016923:Cell Death / Q000276:immunology; D002522:Chlorocebus aethiops; D003208:Concanavalin A / Q000276:immunology; D003546:Cysteine Endopeptidases / Q000172:deficiency / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D003602:Cytotoxicity, Immunologic / Q000502:physiology*; D015870:Gene Expression; D007376:Interleukin-2 / Q000276:immunology; D015979:Killer Cells, Lymphokine-Activated / Q000166:cytology / Q000201:enzymology / Q000276:immunology; D007694:Killer Cells, Natural / Q000166:cytology / Q000201:enzymology / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013154:Spleen / Q000166:cytology / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology / Q000201:enzymology / Q000378:metabolism
D007376:Interleukin-2; D011994:Recombinant Proteins; D003208:Concanavalin A; D002403:Cathepsins; C534187:CTSW protein, human; D056664:Cathepsin W; C534188:Ctsw protein, mouse; D003546:Cysteine Endopeptidases