PSMB9 Human
Description
PSMB9 is fused to a 21 amino acid His-tag at N-terminus & purified by proprietary chromatographic techniques.
Product Specs
The proteasome subunit beta type-9, also known as PSMB9, is a protein that in humans is encoded by the PSMB9 gene. PSMB9 is a member of the proteasome B-type family which is a 20S core beta subunit. It is located within the class II region of the MHC (major histocompatibility complex). Expression of PSMB9 is induced by interferon-gamma (IFN-γ). This induction leads to the replacement of the catalytic subunit 1 (proteasome beta 6 subunit) with PSMB9 in the immunoproteasome.
Product Science Overview
Proteasome Subunit Beta Type 9 (PSMB9), also known as 20S proteasome subunit beta-1i, is a protein encoded by the PSMB9 gene in humans. This protein is a crucial component of the proteasome, a multicatalytic proteinase complex responsible for degrading unneeded or damaged proteins by proteolysis, a chemical reaction that breaks peptide bonds .
The PSMB9 gene is located on chromosome 6 at band 6p21.3. It belongs to the proteasome B-type family, also known as the T1B family. The gene consists of six exons and encodes a protein that is 21 kDa in size and composed of 199 amino acids. The theoretical isoelectric point (pI) of this protein is 4.80 .
PSMB9 is an essential subunit of the 20S core proteasome complex. The proteasome complex has a highly ordered structure composed of four axially stacked rings of 28 non-identical subunits: the two end rings are each formed by seven alpha subunits, and the two central rings are each formed by seven beta subunits . PSMB9, along with other beta subunits, assembles into these rings to form a proteolytic chamber where substrate degradation occurs.
The proteasome has ATP-dependent proteolytic activity and is involved in various cellular processes, including protein quality control, regulation of the cell cycle, and modulation of various signaling pathways . PSMB9 specifically exhibits “trypsin-like” activity, cleaving peptide bonds after basic residues .
Under the influence of interferon-gamma, PSMB9 replaces the constitutive proteasome subunit beta 6 (PSMB6) to form the immunoproteasome. The immunoproteasome plays a critical role in the immune system by processing antigens for presentation on MHC class I molecules, thereby facilitating the immune response .
PSMB9 has been implicated in various diseases, including proteasome-associated autoinflammatory syndromes and certain cancers. For instance, dysregulation of PSMB9 expression has been associated with the development of lower-grade gliomas, a type of brain tumor . Research has shown that PSMB9 can serve as a biomarker for prognosis prediction and as a potential target for immunotherapy in glioma treatment .
