Apolipoprotein J Proteins

Protein Information

Isoform 1 functions as extracellular chaperone that prevents aggregation of nonnative proteins. Prevents stress-induced aggregation of blood plasma proteins. Inhibits formation of amyloid fibrils by APP, APOC2, B2M, CALCA, CSN3, SNCA and aggregation-prone LYZ variants (in vitro). Does not require ATP. Maintains partially unfolded proteins in a state appropriate for subsequent refolding by other chaperones, such as HSPA8/HSC70. Does not refold proteins by itself. Binding to cell surface receptors triggers internalization of the chaperone-client complex and subsequent lysosomal or proteasomal degradation. Secreted isoform 1 protects cells against apoptosis and against cytolysis by complement. Intracellular isoforms interact with ubiquitin and SCF (SKP1-CUL1-F-box protein) E3 ubiquitin-protein ligase complexes and promote the ubiquitination and subsequent proteasomal degradation of target proteins. Promotes proteasomal degradation of COMMD1 and IKBKB. Modulates NF-kappa-B transcriptional activity. Nuclear isoforms promote apoptosis. Mitochondrial isoforms suppress BAX-dependent release of cytochrome c into the cytoplasm and inhibit apoptosis. Plays a role in the regulation of cell proliferation.

Synonyms

AAG4; Aging associated protein 4; Aging-associated gene 4 protein; aging-associated protein 4; AI893575; apo j; Apo J a; Apo J alpha; Apo J b; Apo J beta; Apo J α; Apo J β; Apo Ja; Apo Jb; APOJ; APO-J; ApoJ a; ApoJ alpha; ApoJ b; ApoJ beta; ApoJ α; ApoJ β; ApoJa; ApoJalpha; ApoJb; ApoJbeta; Apolipoprotein J; CLI; CLU; CLU1; CLU2; Clusterin; Clusterin alpha / beta chain; Clusterin alpha chain; Clusterin beta chain; Clustrin; Complement associated protein SP40; complement cytolysis inhibitor; Complement cytolysis inhibitor a chain; Complement cytolysis inhibitor b chain; complement lysis inhibitor; complement-associated protein SP-40,40; D14Ucla3; DAG; Dimeric acid glycoprotein; GP80; HGNC:2095; ku70-binding protein 1; Ku70-binding protein 1 (KUB1); KUB1; MGC24903; Msgp-2; NA1/NA2; RATTRPM2B; SGP2; SGP-2; SP40; SP-40; Sugp-2; Sulfated glycoprotein 2; Sulfated glycoprotein 2 (SGP2); testosterone repressed prostate message; Testosterone repressed prostate message 2; Testosterone repressed prostate message 2 (TPRM2B); testosterone repressed prostate message-2; testosterone-repressed prostate message; testosterone-repressed prostate message 2; testostrone-repressed prostate message 2; Trpm2; TRPM-2; TRPM2B; Trpmb