Proteasome assembly chaperone 2 (PSMG2)

Proteasome assembly chaperone 2 (PSMG2), also known as PAC2, is a dedicated chaperone protein essential for the assembly of the 20S core proteasome in eukaryotic cells[1][4][6][8]. PSMG2 forms a heterodimer with PSMG1 (PAC1), and this complex transiently binds to immature proteasome α-subunit rings. The PAC1/PAC2 heterodimer acts as a molecular scaffold, promoting the correct spatial orientation of α-subunits, preventing off-pathway assembly, and ensuring the formation of the heteroheptameric α-ring, which is critical for subsequent proteasome maturation[1][4][7][8]. After successful assembly, PSMG2 is removed and degraded, and the mature 20S proteasome is formed. Loss-of-function mutations in PSMG2 lead to defective proteasome assembly, reduced proteolytic function, and are implicated in proteasome-associated autoinflammatory syndromes such as PRAAS4/CANDLE[7]. PSMG2 is not considered a direct therapeutic target (such as a receptor, enzyme, or transporter), and there are currently no known drugs or inhibitors specifically targeting this assembly chaperone[4][7][8].

Other names

HCCA3PAC2TNFSF5IP1MDS003MGC15092CLAST3HsT1707PAC-2Hepatocellular carcinoma-susceptibility protein 3Tumor necrosis factor superfamily member 5-induced protein 1hepatocellular carcinoma susceptibility proteinCD40 ligand-activated specific transcript 3PRAAS4HDCMC29PHSPC260x 003 protein