SERPINB9
SERPINB9 (serpin family B member 9, also known as PI9 and CAP3) is an intracellular serine protease inhibitor of the ov-serpin subfamily. It inhibits granzyme B, the effector protease released by cytotoxic T-lymphocytes. Browse Assay Genie's current range of SERPINB9 research reagents below, or read on for the biology behind the target.
SERPINB9 functions as a granzyme B inhibitor. Granzyme B is an effector molecule of cytotoxic T-lymphocytes, and by inhibiting its activity SERPINB9 acts as a regulator of this protease. The protein is localised to the cytoplasm, consistent with its place in a subfamily of intracellular serpins, as opposed to the secreted serpins that act in the extracellular space.
The SERPINB9 gene encodes a member of the serine protease inhibitor family, commonly called serpins. UniProt places the protein in the serpin family, ov-serpin subfamily, and HGNC classifies the gene within the serpin peptidase inhibitors group. Researchers working on this protein may use the SERPINB9 gene symbol, the aliases PI9 and CAP3, or the Serpin B9 protein name, so it is worth searching under each. A pseudogene of this gene is found on chromosome 6.
The best-documented disease-related observation concerns tumour immunology. According to the NCBI Gene summary, overexpression of this protein may prevent cytotoxic T-lymphocytes from eliminating certain tumour cells. This makes SERPINB9 a point of interest wherever granzyme B-mediated killing and immune evasion are studied. Earlier HGNC names for the gene, including serine (or cysteine) proteinase inhibitor, clade B (ovalbumin), member 9, reflect its relationship to ovalbumin-type serpins.
Overexpression of SERPINB9 may prevent cytotoxic T-lymphocytes from eliminating certain tumour cells, making it relevant to studies of resistance to T-cell killing.
SERPINB9 inhibits granzyme B, so it is studied as a control point on this effector protease of cytotoxic T-lymphocytes.
As an intracellular ov-serpin, SERPINB9 is a reference point for comparing how serine protease inhibitors act inside cells.
Because it restrains an effector molecule of cytotoxic T-lymphocytes, SERPINB9 is relevant to work on how cytotoxic cells and their targets are regulated.
SERPINB9 is a granzyme B inhibitor. It belongs to the intracellular serpins and inhibits the activity of granzyme B, an effector molecule of cytotoxic T-lymphocytes. UniProt records the protein in the cytoplasm.
SERPINB9 is also called PI9 and CAP3, and UniProt names the protein Serpin B9. Earlier HGNC names were serine (or cysteine) proteinase inhibitor, clade B (ovalbumin), member 9, and serpin peptidase inhibitor, clade B (ovalbumin), member 9.
The NCBI Gene summary states that overexpression of this protein may prevent cytotoxic T-lymphocytes from eliminating certain tumour cells. This reflects its role as a granzyme B inhibitor. Ortholog information is not given in the source data, so check the datasheet of any product for its validated reactivity.
Other ov-serpin family B members and intracellular serine protease inhibitors with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P50453; product specifications from Assay Genie datasheets.