Proteasome 20S C2 Recombinant Rabbit Monoclonal Antibody [JB89-30]

Function

Proteasome subunit alpha type-1 is a protein that in humans is encoded by the PSMA1 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, and beta5i) that contributes to the complete assembly of 20S proteasome complex. Crystal structures of isolated 20S proteasome complex demonstrate that the two rings of beta subunits form a proteolytic chamber and maintain all their active sites of proteolysis within the chamber. Concomitantly, the rings of alpha subunits form the entrance of substrate entering the proteolytic chamber. In an inactivated 20S proteasome complex, the gate into the internal proteolytic chamber are guarded by N-terminal tails of specific alpha-subunit. The proteolytic capacity of 20S core particle (CP) can be activated when CP associates with one or two regulatory particles (RP) on one or both side of alpha rings. These regulatory particles include 19S proteasome complexes, 11S proteasome complex, etc. Following the CP-RP association, the confirmation of certain alpha subunits will change and consequently cause the opening of substrate entrance gate.

Background References

1. Groettrup M et al. A role for the proteasome regulator PA28alpha in antigen presentation. Nature 381:166-168 (1996).

2. Yano M et al. 20S proteasome prevents aggregation of heat-denatured proteins without PA700 regulatory subcomplex like a molecular chaperone. Biomacromolecules 5:1465-1469 (2004).

Sequence Similarity

Belongs to the peptidase T1A family.

Subcellular Location

Cytoplasm. Nucleus.

UNIPROT

SwissProt: P25786 Human

SwissProt: Q9R1P4 Mouse

SwissProt: P18420 Rat

Synonyms