Serine protease with trypsin- and chymotrypsin-like specificity (, ). Also displays antibacterial activity against Gram-negative and Gram-positive bacteria independent of its protease activity (, ). Prefers Phe and Tyr residues in the P1 position of substrates but also cleaves efficiently after Trp and Leu . Shows a preference for negatively charged amino acids in the P2' position and for aliphatic amino acids both upstream and downstream of the cleavage site . Required for recruitment and activation of platelets which is mediated by the F2RL3/PAR4 platelet receptor (, ). Binds reversibly to and stimulates B cells and CD4(+) and CD8(+) T cells (, ). Also binds reversibly to natural killer (NK) cells and enhances NK cell cytotoxicity through its protease activity (, ). Cleaves complement C3 . Cleaves vimentin (By similarity). Cleaves thrombin receptor F2R/PAR1 and acts as either an agonist or an inhibitor, depending on the F2R cleavage site (, ). Cleavage of F2R at '41-Arg-|-Ser-42' results in receptor activation while cleavage at '55-Phe-|-Trp-56' results in inhibition of receptor activation . Cleaves the synovial mucin-type protein PRG4/lubricin . Cleaves and activates IL36G which promotes expression of chemokines CXCL1 and CXLC8 in keratinocytes . Cleaves IL33 into mature forms which have greater activity than the unprocessed form . Cleaves coagulation factor F8 to produce a partially activated form . Also cleaves and activates coagulation factor F10 . Cleaves leukocyte cell surface protein SPN/CD43 to releases its extracellular domain and trigger its intramembrane proteolysis by gamma-secretase, releasing the CD43 cytoplasmic tail chain (CD43-ct) which translocates to the nucleus . Cleaves CCL5/RANTES to produce RANTES(4-68) lacking the N-terminal three amino acids which exhibits reduced chemotactic and antiviral activities . During apoptosis, cleaves SMARCA2/BRM to produce a 160 kDa cleavage product which localizes to the cytosol . Cleaves myelin basic protein MBP in B cell lysosomes at '224-Phe-|-Lys-225' and '248-Phe-|-Ser-249', degrading the major immunogenic MBP epitope and preventing the activation of MBP-specific autoreactive T cells . Cleaves annexin ANXA1 and antimicrobial peptide CAMP to produce peptides which act on neutrophil N-formyl peptide receptors to enhance the release of CXCL2 . Acts as a ligand for the N-formyl peptide receptor FPR1, enhancing phagocyte chemotaxis . Has antibacterial activity against the Gram-negative bacteria N.gonorrhoeae and P.aeruginosa (, ). Likely to act against N.gonorrhoeae by interacting with N.gonorrhoeae penA/PBP2 . Exhibits potent antimicrobial activity against the Gram-positive bacterium L.monocytogenes . Has antibacterial activity against the Gram-positive bacterium S.aureus and degrades S.aureus biofilms, allowing polymorphonuclear leukocytes to penetrate the biofilm and phagocytose bacteria (, ). Has antibacterial activity against M.tuberculosis . Mediates CASP4 activation induced by the Td92 surface protein of the periodontal pathogen T.denticola, causing production and secretion of IL1A and leading to pyroptosis of gingival fibroblasts .
Subcellular locations: Cell membrane, Cytoplasmic granule, Secreted, Cytoplasm, Cytosol, Lysosome, Nucleus
Secreted by activated neutrophils . Detected in synovial fluid . Localizes to lysosomes in B cells where it is not endogenously synthesized but is internalized from the cell membrane . Localizes to the nucleus during apoptosis .
Expressed in neutrophils (at protein level) . Expressed in B cells .