Cloning and chromosomal assignment of a human cDNA encoding a T cell- and natural killer cell-specific trypsin-like serine protease.

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Abstract
A cDNA clone encoding a human T cell- and natural killer cell-specific serine protease was obtained by screening a phage .gamma.gt10 cDNA library from phytohemagglutinin-stimulated human peripheral blood lymphocytes with the mouse Hanukah factor cDNA clone. In an RNA blothybridization analysis, this human hanukah factor cDNA hybridized with a 1.3-kilobase band in allogeneic-stimulated cyctotoxic T cells and the Jurkat cell line, but this transcript was not detectable in normal muscle, liver, tonsil, or thymus. By dot-blot hybridization, this cDNA hybridized with RNA from three cytolytic T-cell clones and three moncytolytic T-cell clones grown in vitro as well as with purified CD16+ natural killer cells and CD3+, CD16- T-cell large granular lymphocytes from peripheral blood lymphocytes (CD = clusterdesignation). the nucleotide sequence of this cDNA clone encodes a predicted serine protease of 262 amino acids. The predicted protein has a 22-amino acid presegment, a 6-amino acid prosegment,and an active enzyme of 234 amino acids with a calculated unglycosylated molecular weight of 25,820. The active enzyme is 71% and 77% similar to the mouse sequence at the amino acid and DNA levels, respectively. The human and mouse sequences conserve the active site residues of serine proteases- the trypsin-spcific Asp-189 and all 10 cysteine residues. The gene for the human Hanukah factor serine protease is located on human chromosome 5. We propose that this trypsin-like serine protease may function as a common component necessary for lysis of target cells by cytotoxic T lymphocytes and natural killer cells.