Kallikreins are a subgroup of serine proteases, enzymes capable of cleaving peptide bonds in proteins. In humans, plasma kallikrein has no known paralogue, while tissue kallikrein-related peptidases (KLKs) encode a family of fifteen closely related serine proteases. These genes are localised to chromosome 19q13, forming the largest contiguous cluster of proteases within the human genome. Kallikreins are responsible for the coordination of various physiological functions including blood pressure, semen liquefaction and skin desquamation.
Kallikrein-1 is a protein that in humans is encoded by the KLK1 gene. KLK1 is a member of the peptidase S1 family.
Kallikrein-2 is a protein that in humans is encoded by the KLK2 gene, and is particularly associated with prostatic tissue.
Elafin, also known as peptidase inhibitor 3 or skin-derived antileukoprotease (SKALP), is a protein that in humans is encoded by the PI3 gene.
Suppressor of tumorigenicity 14 protein, also known as matriptase, is a protein that in humans is encoded by the ST14 gene. ST14 orthologs have been identified in most mammals for which complete genome data are available.
Kallikrein-6 is a protein that in humans is encoded by the KLK6 gene. Kallikrein-6 is also referred to as neurosin, protease M, hK6, or zyme. It is a 223 amino acid sequence, derived from its 244 original form, which contains a 16 residue presignal and 5 residue activation peptide.
Kallikrein-10 is a protein that in humans is encoded by the KLK10 gene.
Kallikrein-5, formerly known as stratum corneum tryptic enzyme (SCTE), is a serine protease expressed in the epidermis. In humans it is encoded by the KLK5 gene. This gene is one of the fifteen kallikrein subfamily members located in a cluster on chromosome 19. Its expression is up-regulated by estrogens and progestins. Alternative splicing results in multiple transcript variants encoding the same protein.
Kallikrein-related peptidase 4 is a protein which in humans is encoded by the KLK4 gene.
Kallikrein-11 is a protein that in humans is encoded by the KLK11 gene.
Serpin B6 is a protein that in humans is encoded by the SERPINB6 gene.
Kallikrein-related peptidase 7 (KLK7) is a serine protease that in humans is encoded by the KLK7 gene. KLK7 was initially purified from the epidermis and characterised as stratum corneum chymotryptic enzyme (SCCE). It was later identified as the seventh member of the human kallikrein family, which includes fifteen homologous serine proteases located on chromosome 19 (19q13).
Kallikrein-13 is a protein that in humans is encoded by the KLK13 gene.
Kallikrein-8 is a protein that in humans is encoded by the KLK8 gene.
Kallikrein-14 is a protein that in humans is encoded by the KLK14 gene.
Kallikrein-12 is a protein that in humans is encoded by the KLK12 gene.
Sialic acid-binding Ig-like lectin 9 is a protein that in humans is encoded by the SIGLEC9 gene.
Bcl-2-like protein 12 is a protein that in humans is encoded by the BCL2L12 gene.
Kallikrein-related peptidase 9 also known as KLK9 is an enzyme which in humans is encoded by the KLK9 gene.
Judith Ann Clements is an Australian academic and educator, specializing in Kallikrein proteases in prostate and ovarian cancers. Clements is the scientific director at the Australian Prostate Cancer Research Centre – Queensland and was head of the Cancer Research Program at the Institute of Health and Biomedical Innovation (IHBI) of Queensland University of Technology at the Translational Research Institute (Australia) from 1997–2014. Her biography was published in the Cancer and Metastasis Reviews in 2019
