Michelle Shuling Ong, Vinay Tergaonkar; When alpha meets beta, mast cells get hyper. J Exp Med 7 October 2019; 216 (10): 2229–2230. doi: https://doi.org/10.1084/jem.20191169
Abstract:
Tryptase is one of the key secretions of activated mast cells as well as basophils upon antigen challenge. It is a serine protease that is synthesized within secretory granules of these immune cells and is released during degranulation. The ubiquitous presence of tryptase in all mast cells makes it an excellent biomarker for the assessment of allergic responses in patients. Tryptase release promotes the inflammatory response and can lead to tumor angiogenesis (de Souza Junior et al., 2015), mastocytosis, and atopic, fibrotic, and autoimmune disorders (Jogie-Brahim et al., 2004; Cairns, 2005). X-ray crystallography revealed that tryptase exists as a homotetrameric ring-like complex with a central inward-facing catalytic site (Pereira et al., 1998). The buried active site of tryptase limits the accessibility of substrates, thereby conferring protection against the action of biological inhibitors. The tryptase genes are grouped into those producing membrane-bound (γ-tryptase produced from TPSG1) or soluble proteins (α- and βI-tryptases from TPSAB1, βII- and βIII-tryptases from TPSB2, and δ-tryptase from TPSD1; Trivedi et al., 2007).