Biology:TPSB2

Short description: Protein-coding gene in the species Homo sapiens

Generic protein structure example

Tryptase beta-2, also known as tryptase II, is a proteolytic enzyme that in humans is encoded by the TPSB2 gene.

Formerly, the enzyme was known as Tryptase Clara.

Function

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. These 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. The alleles of this gene exhibit an unusual amount of sequence variation, such that the alleles were once thought to represent two separate genes, beta II and beta III.

Beta tryptases appear to be the main isoenzymes expressed in mast cells and club cells, whereas in basophils, alpha-tryptases predominate.

Tryptases have been implicated as mediators in the pathogenesis of asthma and other allergic and inflammatory disorders. In particular, influenza A virus is activated by TPSB2-mediated proteolytic cleavage in the upper respiratory tract.

Further reading

• "Cloning and characterization of a second complementary DNA for human tryptase". The Journal of Clinical Investigation 86 (3): 864–870. September 1990. doi:10.1172/JCI114786. PMID 2203827. 
• "Structural requirements and mechanism for heparin-dependent activation and tetramerization of human betaI- and betaII-tryptase". Journal of Molecular Biology 345 (1): 129–139. January 2005. doi:10.1016/j.jmb.2004.10.029. PMID 15567416. 
• "The human mast cell tryptase tetramer: a fascinating riddle solved by structure". Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology 1477 (1–2): 75–89. March 2000. doi:10.1016/s0167-4838(99)00265-4. PMID 10708850. 
• "Human tryptases alpha and beta/II are functionally distinct due, in part, to a single amino acid difference in one of the surface loops that forms the substrate-binding cleft". The Journal of Biological Chemistry 274 (28): 19670–19676. July 1999. doi:10.1074/jbc.274.28.19670. PMID 10391906. 
• "Characterization of human gamma-tryptases, novel members of the chromosome 16p mast cell tryptase and prostasin gene families". Journal of Immunology 164 (12): 6566–6575. June 2000. doi:10.4049/jimmunol.164.12.6566. PMID 10843716. 
• "Human mast cell tryptase: multiple cDNAs and genes reveal a multigene serine protease family". Proceedings of the National Academy of Sciences of the United States of America 87 (10): 3811–3815. May 1990. doi:10.1073/pnas.87.10.3811. PMID 2187193. Bibcode: 1990PNAS...87.3811V. 
• "Characterization of two highly polymorphic human tryptase loci and comparison with a newly discovered monkey tryptase ortholog". Pharmacogenetics 10 (5): 389–396. July 2000. doi:10.1097/00008571-200007000-00002. PMID 10898108. 
• "Characterization of a tryptase mRNA expressed in the human basophil cell line KU812". Scandinavian Journal of Immunology 37 (2): 203–208. February 1993. doi:10.1111/j.1365-3083.1993.tb01757.x. PMID 8434231. 
• "Characterization of genes encoding known and novel human mast cell tryptases on chromosome 16p13.3". The Journal of Biological Chemistry 274 (6): 3355–3362. February 1999. doi:10.1074/jbc.274.6.3355. PMID 9920877. 
• "New developments in the genetics and activation of mast cell proteases". Molecular Immunology 38 (16–18): 1353–1357. September 2002. doi:10.1016/S0161-5890(02)00087-1. PMID 12217407. 
• "Tryptase haplotype in mastocytosis: relationship to disease variant and diagnostic utility of total tryptase levels". Clinical Immunology 123 (3): 268–271. June 2007. doi:10.1016/j.clim.2007.02.007. PMID 17449330. 
• "The structure of the human betaII-tryptase tetramer: fo(u)r better or worse". Proceedings of the National Academy of Sciences of the United States of America 96 (20): 10984–10991. September 1999. doi:10.1073/pnas.96.20.10984. PMID 10500112. Bibcode: 1999PNAS...9610984S. 
• "Sequence, structure and pathology of the fully annotated terminal 2 Mb of the short arm of human chromosome 16". Human Molecular Genetics 10 (4): 339–352. February 2001. doi:10.1093/hmg/10.4.339. PMID 11157797. 
• "Human subjects are protected from mast cell tryptase deficiency despite frequent inheritance of loss-of-function mutations". The Journal of Allergy and Clinical Immunology 124 (5): 1099–1105.e4. November 2009. doi:10.1016/j.jaci.2009.07.026. PMID 19748655. 
• "Human beta-tryptase is a ring-like tetramer with active sites facing a central pore". Nature 392 (6673): 306–311. March 1998. doi:10.1038/32703. PMID 9521329. Bibcode: 1998Natur.392..306P. 
• "Systematic identification of SH3 domain-mediated human protein-protein interactions by peptide array target screening". Proteomics 7 (11): 1775–1785. June 2007. doi:10.1002/pmic.200601006. PMID 17474147. 

This article incorporates text from the United States National Library of Medicine, which is in the public domain.