Identification and sequencing of cDNA clones encoding the granule-associated serine proteases granzymes D, E, and F of cytolytic T lymphocytes.
Cytoplasmic granules of cytolytic T lymphocytes contain at least six related serine esterases (granzymes) that are released together with perforin, a pore-forming protein related to complement component C9, during target-cell lysis. Polyclonal antibodies were used to isolate a large number of cDNA clones from an expression library derived from cytolytic-T-cell mRNA. Three distinct full-length cDNA clones coding for granzymes D, E, and F were identified by restriction site mapping and nucleotide sequencing. The three deduced amino acid sequences are highly similar to one another (between 72% and 90% amino acid identities) and to the sequences of granzymes B and C, cathepsin G, and rat mast-cell proteases I and II (between 43% and 57% amino acid identities). Cysteine residues capable of forming intramolecular disulfide bonds are conserved, as are the catalytic-site residues characteristic of serine proteases. Comparison of the cDNA-derived protein sequences with the amino termini of the isolated granzymes provides evidence that they are stored in a fully processed, activated form after removal of the signal peptide and two additional residues (propeptide) at the amino terminus. Immunoelectron microscopic studies demonstrated that granzymes D, E, and F are present in the same morphologically distinct cytoplasmic granules in which perforin has been found previously.
Jenne
D
D
Institut de Biochimie, Université de Lausanne, Epalinges, Switzerland.
Rey
C
C
Haefliger
J A
JA
Qiao
B Y
BY
Groscurth
P
P
Tschopp
J
J
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003594:Cytoplasmic Granules / Q000201:enzymology; D004247:DNA / Q000235:genetics; D053804:Granzymes; D051379:Mice; D008810:Mice, Inbred C57BL / Q000235:genetics; D008969:Molecular Sequence Data; D012689:Sequence Homology, Nucleic Acid; D012697:Serine Endopeptidases / Q000235:genetics*; D013602:T-Lymphocytes, Cytotoxic / Q000201:enzymology* / Q000648:ultrastructure
D004247:DNA; D053804:Granzymes; C056483:Gzmd protein, mouse; C056484:Gzme protein, mouse; C056485:Gzmf protein, mouse; D012697:Serine Endopeptidases