tryptase delta 1(TPSD1) Homo sapiens Tryptases comprise a family of trypsin-like serine proteases, the peptidase family S1. Tryptases are enzymatically active only as heparin-stabilized tetramers, and they are resistant to all known endogenous proteinase inhibitors. Several tryptase genes are clustered on chromosome 16p13.3. These genes are characterized by several distinct features. They have a highly conserved 3 UTR and contain tandem repeat sequences at the 5 flank and 3 UTR which are thought to play a role in regulation of the mRNA stability. Although this gene may be an exception, most of the tryptase genes have an intron immediately upstream of the initiator Met codon, which separates the site of transcription initiation from protein coding sequence. This feature is characteristic of tryptases but is unusual in other genes. Tryptases have been implicated as mediators in the pathogenesis of asthma and other allergic andcatalytic activity:Preferential cleavage: Arg-|-Xaa, Lys-|-Xaa, but with more restricted specificity than trypsin.,caution:Although PubMed:11174199 reported this as a pseudogene, PubMed:12391231 showed it is expressed and has proteolytic activity when expressed in bacterial cells.,function:Tryptase is the major neutral protease present in mast cells and is secreted upon the coupled activation-degranulation response of this cell type.,similarity:Belongs to the peptidase S1 family. Tryptase subfamily.,similarity:Contains 1 peptidase S1 domain.,subcellular location:Released from the secretory granules upon mast cell activation.,subunit:Homotetramer.,tissue specificity:Expressed in colon, lung, heart and synovial tissue. May be specific to mast cells.,
