TPSAB1
Encyclopedia
Tryptase alpha-1 and tryptase beta-1 are enzyme
s that in humans are encoded by the same TPSAB1 gene
. Beta tryptases appear to be the main isoenzymes expressed in mast cell
s; whereas in basophils, alpha tryptases predominate.
s 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, alpha and beta 1.Tryptases have been implicated as mediators in the pathogenesis of asthma and other allergic and inflammatory disorders.
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
s that in humans are encoded by the same TPSAB1 gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
. Beta tryptases appear to be the main isoenzymes expressed in mast cell
Mast cell
A mast cell is a resident cell of several types of tissues and contains many granules rich in histamine and heparin...
s; whereas in basophils, alpha tryptases predominate.
Function
TryptaseTryptase
Tryptase is the most abundant secretory granule-derived serine proteinase contained in mast cells that has been used as a marker for mast cell activation. It is involved with allergenic response and is suspected to act as a mitogen for fibroblast lines...
s 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, alpha and beta 1.Tryptases have been implicated as mediators in the pathogenesis of asthma and other allergic and inflammatory disorders.