CLU
Description
The CLU (clusterin) is a protein-coding gene located on chromosome 8.
The term CLU can refer to:
CLU isoform 1 functions as an extracellular chaperone that prevents aggregation of non-native proteins. It prevents stress-induced aggregation of blood plasma proteins and inhibits the formation of amyloid fibrils by various proteins, including APP, APOC2, B2M, CALCA, CSN3, SNCA, and aggregation-prone LYZ variants. It does not require ATP and maintains partially unfolded proteins in a state suitable for subsequent refolding by other chaperones, such as HSPA8/HSC70. CLU does not refold proteins by itself. Binding to cell surface receptors triggers internalization of the chaperone-client complex and subsequent lysosomal or proteasomal degradation. It protects cells against apoptosis and complement-mediated cytolysis. Intracellular forms interact with ubiquitin and SCF (SKP1-CUL1-F-box protein) E3 ubiquitin-protein ligase complexes and promote ubiquitination and subsequent proteasomal degradation of target proteins. This isoform promotes proteasomal degradation of COMMD1 and IKBKB and modulates NF-kappa-B transcriptional activity. A mitochondrial form suppresses BAX-dependent release of cytochrome c into the cytoplasm, inhibiting apoptosis. CLU plays a role in regulating cell proliferation. An intracellular form suppresses stress-induced apoptosis by stabilizing mitochondrial membrane integrity through interaction with HSPA5. The secreted form does not affect caspase or BAX-mediated intrinsic apoptosis or TNF-induced NF-kappa-B activity. Secreted forms act as important modulators during neuronal differentiation through interaction with STMN3. CLU also plays a role in the clearance of immune complexes that arise during cell injury.
CLU is also known as AAG4, APO-J, APOJ, CLI, CLU1, CLU2, KUB1, NA1/NA2, SGP-2, SGP2, SP-40, TRPM-2, TRPM2.
