Proteasome

Supporting information

The proteasome complex is a broad spectrum protease present in all eukaryotes, which functions to carry out selective, efficient and progressive hydrolysis of intracellular target proteins. The proteasome plays a prominent role in the control of a diverse array of basic cellular processes by rapidly catalyzing numerous biological reactions.

The proteasome complex is composed of a 20S catalytic core and one or two terminal 19S regulatory units. The 20S catalytic domain is barrel-shaped and consists of seven structurally similar α- and β-subunits. In the inactive state, the external α-subunits act as a physical barrier to prevent peptide substrates accessing the active site on the β-subunits. The 19S regulatory units recognize proteins marked by polyubiquitin chains, remove the chain, entrap the protein moiety and open the 20S α-subunits allowing the β-subunits to degrade the protein. Assembly of the 20S domain is very complex and requires extrinsic (eg PAC1) and intrinsic (eg C-tail of β-subunits) chaperones. The assembly mechanism of the 19S domain is poorly understood, but Hsp90 is thought to play a role.

Regulation of the proteasome complex is mediated by proteasome interacting proteins (PIPs). There are two classes of PIPs; protein factors related to the ubiquitylation system such as the deubiquitylating enzyme, Usp14 and auxillary factors that regulate proteasome functions via direct binding, for example Ecm29.

View all products for Proteasome »

Gene	Species	Gene Symbol	Gene Accession No.	Protein Accession No.

α1	Human	PSMA1	NM_002786	P25786
	Mouse	Psma1	NM_011965	Q9R1P4
	Rat	Psma1	NM_017278	P18420
α2	Human	PSMA2	NM_002787	P25787
	Mouse	Psma2	NM_008944	P49722
	Rat	Psma2	NM_017279	Q6P9V5
View all Proteasome Gene Data »