PSA
PSA (prostate-specific antigen), encoded by the KLK3 gene and also known as kallikrein-3 or APS, is a secreted serine protease of the kallikrein family. It hydrolyses semenogelin-1, which leads to liquefaction of the seminal coagulum, and its serum level is a widely used clinical marker in prostate disease. Browse Assay Genie's current range of PSA research reagents below, or read on for the biology behind the target.
PSA is a protease that hydrolyses semenogelin-1, the high molecular mass seminal vesicle protein, and in doing so brings about the liquefaction of the seminal coagulum. It belongs to the peptidase S1 family and the kallikrein subfamily, and is classified as EC 3.4.21.77. Kallikreins are a subgroup of serine proteases with diverse physiological functions, and PSA is one of the best-known members of the group.
The KLK3 gene encodes a single-chain glycoprotein that is synthesised in the epithelial cells of the prostate gland and is present in seminal plasma. The mature protein is secreted. KLK3 is one of fifteen kallikrein subfamily genes found together in a cluster on chromosome 19, at 19q13.33. Alternate splicing of the gene generates several transcript variants that encode different isoforms, which is worth bearing in mind when choosing reagents for a particular form of the protein.
The gene has carried several names. HGNC records the previous names kallikrein 3 and (prostate specific antigen), with PSA and APS as aliases, and the current approved name is kallikrein related peptidase 3. In the clinical setting the serum level of the protein is called PSA, and it is useful in the diagnosis and monitoring of prostatic carcinoma. More broadly, growing evidence suggests that many kallikreins are implicated in carcinogenesis, and some have potential as novel cancer and other disease biomarkers. This makes PSA a reference point for work on the wider kallikrein family as well as on the prostate itself.
Serum PSA is used clinically in the diagnosis and monitoring of prostatic carcinoma, making it a standard reference marker in prostate cancer studies.
PSA is present in seminal plasma and hydrolyses semenogelin-1, so it is central to studies of seminal coagulum liquefaction.
As one of fifteen kallikrein genes clustered on chromosome 19, KLK3 is a natural comparator in work on kallikrein function and carcinogenesis.
PSA is a secreted glycoprotein protease of the peptidase S1 family, relevant to studies of substrate specificity and proteolytic activity.
PSA is a serine protease that hydrolyses semenogelin-1, leading to liquefaction of the seminal coagulum. It is made by prostate epithelial cells and is present in seminal plasma. In clinical use, its serum level helps in the diagnosis and monitoring of prostatic carcinoma.
The approved name is kallikrein related peptidase 3. Aliases are PSA and APS, and earlier names include kallikrein 3 and (prostate specific antigen). Alternate splicing of the KLK3 gene produces several transcript variants that encode different isoforms.
The rat ortholog is listed as Klk3 and the mouse ortholog as Klkb1 in the data used here. PSA is linked to prostatic carcinoma through its clinical use as a serum marker; check the datasheet of any product for its validated reactivity.
Other kallikrein family proteases, including KLK2 and plasma kallikrein, that are often studied alongside PSA in prostate and cancer research.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P07288; product specifications from Assay Genie datasheets.