KLK9
KLK9 (kallikrein related peptidase 9, also known as kallikrein 9 or KLK-L3) is a secreted serine protease of the kallikrein subfamily. It belongs to the peptidase S1 family and is studied as a hormone-responsive marker in cancer research. Browse Assay Genie's current range of KLK9 research reagents below, or read on for the biology behind the target.
KLK9 is a kallikrein-related serine protease. It belongs to the peptidase S1 family and the kallikrein subfamily, and carries the enzyme classification EC 3.4.21.-, which covers serine endopeptidases that have not been assigned a more specific number. UniProt lists the mature protein as secreted, although the NCBI Gene summary notes that the encoded protein is found primarily in the cytoplasm. Researchers working with the KLK9 protein should therefore consider both compartments when designing experiments.
The KLK9 gene is the ninth member of the kallikrein group in the HGNC classification, where it is named kallikrein related peptidase 9 and was previously called kallikrein 9. The alias KLK-L3 also appears in the literature. The human gene is located at 19q13.41 and encodes Kallikrein-9, a 250-amino-acid protein. Orthologues are recorded in the mouse as Klk1b9 and in the rat as Klk9.
A notable feature reported in the NCBI Gene summary is that the gene is activated by steroid hormones in a human breast cancer cell line. This hormone responsiveness has led to KLK9 being described as a good marker for cancer detection. The source annotation does not give a detailed substrate profile or physiological role, so much of the current interest in KLK9 centres on its regulation and its relationship to other members of the kallikrein family, such as KLK1, KLK2 and KLK4. Studies commonly use a KLK9 antibody or a KLK9 ELISA kit format to examine expression and abundance in tissue and biological fluids.
KLK9 is activated by steroid hormones in a breast cancer cell line and has been described as a good marker for cancer detection.
Hormone-dependent activation of the KLK9 gene makes it a useful model for studying steroid-responsive transcription in breast cancer cells.
As a member of the kallikrein subfamily of peptidase S1 serine proteases, KLK9 is studied alongside related kallikrein-related peptidases.
KLK9 is annotated as secreted yet reported primarily in the cytoplasm, making its subcellular distribution a question for cell biology research.
KLK9 is a kallikrein-related serine protease of the peptidase S1 family. The available annotation does not define its substrates or physiological role. It is best known as a gene activated by steroid hormones in a human breast cancer cell line, which has made it a candidate marker for cancer detection.
The HGNC approved name is kallikrein related peptidase 9, with the previous name kallikrein 9 and the alias KLK-L3. UniProt names the protein Kallikrein-9. Literature and catalogues may use any of these terms, so searching under each is helpful.
Yes. The mouse ortholog is Klk1b9 and the rat ortholog is Klk9. Note the different mouse nomenclature when searching databases. For any product, check the datasheet for its validated reactivity before using it with a given species.
Other kallikrein-related peptidases and plasma kallikrein with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q9UKQ9; product specifications from Assay Genie datasheets.