PSMA6
Description
The PSMA6 (proteasome 20S subunit alpha 6) is a protein-coding gene located on chromosome 14.
Proteasome subunit alpha type-6 is a protein that in humans is encoded by the PSMA6 gene. This protein is one of the 17 essential subunits (alpha subunits 1–7, constitutive beta subunits 1–7, and inducible subunits including beta1i, beta2i, beta5i) that contributes to the complete assembly of 20S proteasome complex.
== Structure ==
=== Protein expression === The gene PMSA6 encodes a member of the peptidase T1A family, that is a 20S core alpha subunit. A pseudogene has been identified on the Y chromosome. The gene has 8 exons and locates at chromosome band 14q13. The human protein proteasome subunit alpha type-6 is also known as 20S proteasome subunit alpha-1 (based on systematic nomenclature). The protein is 27 kDa in size and composed of 246 amino acids. The calculated theoretical pI (isoelectric point) of this protein is 6.35.
=== Complex assembly === The proteasome is a multicatalytic proteinase complex with a highly ordered 20S core structure. This barrel-shaped core structure is composed of 4 axially stacked rings of 28 non-identical subunits: the two end rings are each formed by 7 alpha subunits, and the two central rings are each formed by 7 beta subunits.
PSMA6, also known as proteasome subunit alpha type-6, is a component of the 20S core proteasome complex, which is involved in the breakdown of most proteins within cells. This complex performs crucial functions by associating with various regulatory particles. When bound to two 19S regulatory particles, it forms the 26S proteasome, which participates in the ATP-dependent degradation of ubiquitinated proteins. The 26S proteasome is essential for maintaining protein homeostasis by eliminating misfolded or damaged proteins that could harm cellular functions, as well as proteins whose functions are no longer needed. The 20S proteasome can also associate with PA200 or PA28, mediating ubiquitin-independent protein degradation. This type of proteolysis is critical in pathways like spermatogenesis (20S-PA200 complex) and the generation of a subset of MHC class I-presented antigenic peptides (20S-PA28 complex).
PSMA6 is also known as IOTA, PROS27, p27K.
