Proteasome

PSMG4 is a chaperone protein that enhances assembly of the 20S proteasome. PSMG4 cooperates with alpha and beta subunits of the 20S proteasome and with PSMG3 but disconnects when the POMP is recruited before the formation of half-proteasomes.

PSMG3 is a chaperone protein that promotes assembly of the 20S proteasome. PSMG3 may cooperate with PSMG1-PSMG2 heterodimers to coordinate the correct assembly of proteasomes. PSMG3 interacts with PSMG4, as well as directly with alpha and beta subunits of the 20S proteasome but dissociates prior to the formation of half-proteasomes, probably upon recruitment of POMP.

Proteasome assembly chaperone 2 (PSMG2) stimulates assembly of the 20S proteasome as part of a heterodimer with PSMG1. The PSMG1-PSMG2 heterodimer binds to the PSMA5 and PSMA7 proteasome subunits and promotes compilation of the proteasome alpha subunits into the heteroheptameric alpha ring and prevents alpha ring dimerization. PSMG2 is widely expressed with highest levels in the lung, brain and colon. It is moderately expressed in the muscle, stomach, spleen and heart, and weakly expressed in the small intestine, pancreas and liver. It is also highly expressed in hepatocellular carcinomas with low levels in surrounding liver tissue.

PSMF1 is a protein which hinders the activation of the proteasome by the 11S and 19S regulators. The 26S proteasome is a multicatalytic proteinase complex with an extremely ordered structure composed of 2 complexes, a 20S core and a 19S regulator. The 20S core is comprised of 4 rings of 28 non-identical subunits; 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits.

PSME3 is a member of the PA28 family. The 26S proteasome is an extremely organized multicatalytic proteinase complex composed of 2 complexes, a 20S core and a 19S regulator. Proteasomes are spread all over the eukaryotic cells in large quantities and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. PSME3 stimulates the trypsin-like catalytic subunit of the proteasome and inhibits the chymotrypsin-like and postglutamyl-preferring (PGPH) subunits. PSEM3 enables the MDM2-p53/TP53 collaboration that encourages ubiquitination- and MDM2-dependent proteasomal degradation of p53/TP53, restricting its growth and causing inhibited apoptosis after DNA damage.

PSME2 is an IFN-gamma inducible proteasome activator essential for production of several key histocompatibility (MHC) class I antigens. Downregulation of PSME2 causes unusual proteasome activation and is connected to the development of intimal hyperplasia (IH) in animal models.

PSME1 is a Proteasome Activator 28 subunit alpha essential for presentation of certain major histocompatibility (MHC) class I antigens. The PSME1 complex is an alternate proteasome activator which operates with no use of ubiquitin. The PSME1 complex is made out of two homologous subunits, alpha and beta, that functions in similar catalytic properties and is connected to a hexameric ring.

PSMD9 is a multicatalytic proteinase complex with a highly ordered structure composed of 2 complexes, a 20S core and a 19S regulator. PSMD9 acts as a chaperone through the assembly of the 26S proteasome, specifically of the base subcomplex of the PA700/19S regulatory complex (RC). During the base subcomplex compilation, PSMD9 is part of an intermediate PSMD9:PSMC6:PSMC3 module, also called modulator trimer complex. PSMD9 is released during the further base assembly process.

Proteasome 26S Subunit, Non-ATPase 5, also known as PSMD5 is a member of the proteasome subunit S5B/HSM3 family. The 26S proteasome is an enzymatic complex which degrades ubiquitinated proteins in eukaryotic cells. Furthermore, PSMD5 acts as a chaperones which is involved in the assembly of the 26s proteasome, particularly of the base subcomplex of the PA700/19S regulatory complex. PSMD5 is full of dileucine repeats, which have been involved in trafficking of various transmembrane proteins.

Proteasome 26S Subunit, Non-ATPase 13 (PSMD13) is a part of the proteasome subunit S11 family and contains one PCI domain. PSMD13 plays a role as a regulatory subunit of the 26S proteasome which takes part in the ATP-dependent degradation of ubiquitinated proteins.

The 26S proteasome is a multicatalytic proteinase complex with a well ordered structure composed of two complexes- a 20S core and a 19S regulator. PSMD11 is a non-ATPase subunit of the 19S regulator. The 20S core is composed of four rings of 28 non-identical subunits; two rings are composed of 7 alpha subunits and two rings are composed of 7 beta subunits. The 19S regulator is composed of a base that contains six ATPase subunits and two non-ATPase subunits, and a lid that contains up to ten non-ATPase subunits. Proteasomes are spread throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. An indispensable function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides.

Gankyrin (proteasome 26S subunit) is a multicatalytic proteinase oncoprotein commonly overexpressed in most hepatocellular carcinomas. Proteasomes are found throughout eukaryotic cells at a high concentrations and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. Gankyrin interacts with S6 ATPase of the 19S regulatory particle of the 26S proteasome. Gankyrin is involved in theregulation of the phosphorylation of the retinoblastoma protein by CDK4, and to enhance the ubiquitinylation of p53 by MDM2. Gankyrin consists of 7 ankyrin repeats and is structurally similar to I kappa Bs. Gankyrin acts as a regulatory subunit of the 26s proteasome which is involved in the atp-dependent degradation of ubiquitinated proteins. Gankyrin is involved in progression of esophageal squamous cell carcinoma. gankyrin plays an oncogenic role especially in early stages of human epatocarcinogenesis. Gankyrin binds to NF-kappaB and suppresses its activity at the transcription level by modulating acetylation through SIRT1. Structural comparison between Gankyrin & p16(INK4A) identified numerous residues of gankyrin that are potentially important for CDK4 binding.

Proteasome subunit beta type-9 (PSMB9) belongs to the proteasome B-type family which is a 20S core beta subunit. PSMB9 is positioned in the class II region of the MHC (major histocompatibility complex). Expression of the PSMB9 protein is induced by INFG and this gene product replaces catalytic subunit 1 (proteasome beta 6 subunit) in the immunoproteasome.

Proteasome Subunit Beta Type 8 (PSMB8) is a member of the peptidase T1B family. The proteasome is a multicatalytic proteinase complex with well-organized ring-shaped 20S core structure. Proteasomes are spread through eukaryotic cells at a high concentration. PSMB8 is mainly expressed in immature dendritic cells. vital function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides.PSMB8 is positioned in the class II region of the MHC (main histocompatibility complex). PSMB8 plays as a significant factor of INFG-induced sensitivity and in apoptosis by degradation of the apoptotic inhibitor MCL1.

Proteasome subunit beta type-7 (PSMB7) belongs to the proteasome B-type family. PSMB7 is a multicatalytic proteinase complex with an extremely ordered ring-shaped 20S core structure. This core structure is comprised of 4 rings of 28 non-identical subunits; 2 rings are comprised of 7 alpha subunits and 2 rings are comprised of 7 beta subunits. Proteasomes are scattered all over eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent manner in a non-lysosomal pathway. The processing of class I MHC peptides is a vital function of the immunoproteasome (which is a modified proteasome).

PSMB6 belongs to the proteasome B-type family (T1B family) which is a 20S core beta subunit in the proteasome. The PSMB6 is not present in the immunoproteasome and is replaced by PSMB9. The proteasome is a multicatalytic proteinase complex with an extremely ordered ring-shaped 20S core structure. The core structure is comprised of 4 rings of 28 non-identical subunits; 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits.

PSMB5 belongs to the proteasome B-type family that has a 20S core beta subunit in the proteasome. This catalytic subunit is not present in the immunoproteasome and is substituted by catalytic subunit 3i (proteasome beta 8 subunit). A fundamental function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides. PSMB5 exhibits an ATP dependent proteolytic activity and is involved in an ATP/ubiquitin dependent non lysosomal proteolytic pathway.

PSMB4 is a member of the peptidase T1B family. The 20S Proteasome chamber holds structural alpha subunits and predominantly catalytic beta subunits. The two external rings in the proteasome contain seven alpha subunits each and the two internal rings contain of seven beta subunits each. PSMB4 is a beta subunit of the 20S Proteasome that is spread all over the eukaryotic cells in large quantities and cleaves peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway.

The proteasome is a multicatalytic proteinase complex with an extremely organized ring-shaped 20S core structure. The core structure consists of 4 rings of 28 non-identical subunits; 2 rings consist of 7 alpha subunits and 2 rings consist of 7 beta subunits. Proteasomes are spread all over the eukaryotic cells in large quantities and cleave peptides in an ATP/ubiquitin-dependent procedure in a non-lysosomal pathway. A vital role of a modified proteasome, the immunoproteasome, is the handling of class I MHC peptides.

Proteasome subunit beta type-2 (PSMB2) belongs to the proteasome T1B family, which is a 20S core beta subunit. The proteasome is a multicatalytic proteinase complex with a highly ordered ring-shaped 20S core structure. Proteasomes are spread throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. A crucial function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides. PSMB2 is up-regulated in ovarian cancer cell lines.

PSMB10 is a member of the proteasome B-type family (T1B family) which is a 20S core beta subunit. The proteasome is a multicatalytic proteinase complex with an extremely ordered ring-shaped 20S core structure. This core structure is comprised of four rings of 28 non-identical subunits; two rings are composed of seven alpha subunits and two rings are composed of seven beta subunits. Proteasomes are circulated in eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. A crucial function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides. PSMB10 gene expression is induced by INFg, and it replaces catalytic subunit 2 (proteasome beta 7 subunit) in the immunoproteasome.

PSMB1 is part of the proteasome B-type family, also identified as the T1B family, that is a 20S core beta subunit. PSMB1 is tightly linked to the TBP (TATA-binding protein) gene in human and in mouse, and is transcribed in the opposite orientation in both species.The main function of PSMB1 is its degradation activity of unnecessary or damaged proteins by proteolysis. PSMB1 is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with arg, phe, tyr, leu, and glu adjacent to the leaving group at neutral or slightly basic ph. the proteasome has an atp-dependent proteolytic activity.

Proteasome subunit alpha type-8 (PSMA8) is a member of the peptidase T1A family. PSMA8 is a multicatalytic proteinase complex which is distinguished by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. The proteasome has an ATP-dependent proteolytic activity. The PSMA8 subunit may be testis-specific.

The proteasome is a multicatalytic proteinase complex with a highly assembled ring-shaped 20S core structure which is composed of 4 rings of 28 non-identical subunits, 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. Proteasomes are found throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. PSMA7 is part of the peptidase T1A family, that is a 20S core alpha subunit. PSMA7 interacts particularly with the hepatitis B virus X protein, a protein critical to viral replication. PSMA7 is involved in regulating hepatitis virus C internal ribosome entry site activity that is crucial for viral replication. PSMA7 is in charge for regulating the hypoxia-inducible factor-1alpha, a transcription factor important for cellular responses to oxygen tension. PSMA7 is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. PSMA7 interacts specifically with two subdomains of HIF-1alpha and inhibited the transactivation function of HIF-1alpha under both normoxic and hypoxia-mimicking conditions.

PSMA6 belongs to the peptidase T1A family, which is a 20S core alpha subunit. The proteasome is a multicatalytic proteinase complex with an extremely organized ring-shaped 20S core structure. The core structure consists of 4 rings of 28 non-identical subunits; 2 rings consist of 7 alpha subunits and 2 rings consist of 7 beta subunits. PSMA6 is spread all over eukaryotic cells in large quantities and cleave peptides in an ATP/ubiquitin-dependent procedure in a non-lysosomal pathway.

Proteasome subunit alpha type-5 (PSMA5) is a member of the peptidase T1A family. The proteasome is a multicatalytic proteinase complex which is distinguished by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. Proteasomes are spread throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. PSMA5 interacts with PLK1. The PSMA5 peptidase has a very wide-ranging specificity for cleavage of peptide bonds.

Proteasome subunit alpha type 4 (PSMA4) belongs to the peptidase T1A family, which is a 20S core alpha subunit. The proteasome is a multicatalytic proteinase complex with an extremely ordered ring-shaped 20S core structure. The core structure is comprised of 4 rings of 28 non-identical subunits; 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. PSMA4 is dispersed throughout eukaryotic cells at a high concentration and cleaves peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway.

The proteasome is a multicatalytic proteinase complex which holds an extremely organized 20S core structure shaped like a ring. The central structure is assembled from 4 rings of 28 non-identical subunits; 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. There is a high concentration of proteasomes all over the eukaryotic cells and their job is to cleave peptides in an ATP/ubiquitin-dependent procedure in a non-lysosomal pathway. PSMA3 encodes several of the peptidase T1A family which is a 20S core alpha subunit. Two alternative transcripts encoding diverse isoforms were recognized.

Proteasome subunit alpha type-2 (PSMA2) is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. PSMA2 is a 20S core alpha subunit of proteasome belonging to the peptidase T1A family. PSMA2 functions as a docking domain for the regulatory particles and exterior gates blocking unregulated access to the inner cavity.

PSMA1 is a prosomal protein who takes part in a nonlysosomal ATP/ubiquitin-dependent proteolytic pathway. PSMA1 is a multicatalytic proteinase complex that is characterized by its capacity to cleave peptides with Arg, Phe, Tyr, Leu, and Glu next to the leaving group at neutral or slightly basic pH. PSMA1 is vastly expressed in prostate epithelium.