Summary
Basic Information
Immunogen
Human recombinant protein fragment corresponding to amino acids 23-227 of human CLU (NP_976084) produced in E.coli
Application Notes
The COA includes recommended starting dilutions, optimal dilutions should be determined by the end user.
Formulations & Storage [For reference only, actual COA shall prevail!]
Storage
Store at +4°C short term (1-2 weeks). Aliquot and store at -20°C long term. Avoid repeated freeze/thaw cycles.
Target
Alternative Names
Collagen Type I Alpha 1 Chain; Collagen, Type I, Alpha 1; Alpha-1 Type I Collagen; Collagen Of Skin, Tendon And Bone, Alpha-1 Chain; Collagen Alpha-1(I) Chain Preproprotein; Type I Procollagen Alpha 1 Chain; Collagen Alpha 1 Chain Type I; Pro-Alpha-1 Collagen Type 1; Collagen Alpha-1(I) Chain;
Function
Isoform 1:
Functions as extracellular chaperone that prevents aggregation of non native proteins (PubMed:11123922, PubMed:19535339).
Prevents stress-induced aggregation of blood plasma proteins (PubMed:11123922, PubMed:12176985, PubMed:17260971, PubMed:19996109).
Inhibits formation of amyloid fibrils by APP, APOC2, B2M, CALCA, CSN3, SNCA and aggregation-prone LYZ variants (in vitro) (PubMed:12047389, PubMed:17412999, PubMed:17407782).
Does not require ATP (PubMed:11123922).
Maintains partially unfolded proteins in a state appropriate for subsequent refolding by other chaperones, such as HSPA8/HSC70 (PubMed:11123922).
Does not refold proteins by itself (PubMed:11123922).
Binding to cell surface receptors triggers internalization of the chaperone-client complex and subsequent lysosomal or proteasomal degradation (PubMed:21505792).
Protects cells against apoptosis and against cytolysis by complement (PubMed:2780565).
Intracellular forms 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 (PubMed:20068069).
Promotes proteasomal degradation of COMMD1 and IKBKB (PubMed:20068069).
Modulates NF-kappa-B transcriptional activity (PubMed:12882985).
A mitochondrial form suppresses BAX-dependent release of cytochrome c into the cytoplasm and inhibit apoptosis (PubMed:16113678, PubMed:17689225).
Plays a role in the regulation of cell proliferation (PubMed:19137541).
An intracellular form suppresses stress-induced apoptosis by stabilizing mitochondrial membrane integrity through interaction with HSPA5 (PubMed:22689054).
Secreted form does not affect caspase or BAX-mediated intrinsic apoptosis and TNF-induced NF-kappa-B-activity (PubMed:24073260).
Secreted form act as an important modulator during neuronal differentiation through interaction with STMN3 (By similarity).
Plays a role in the clearance of immune complexes that arise during cell injury (By similarity).
Isoform 6:
Does not affect caspase or BAX-mediated intrinsic apoptosis and TNF-induced NF-kappa-B-activity.
Isoform 4:
Does not affect caspase or BAX-mediated intrinsic apoptosis and TNF-induced NF-kappa-B-activity (PubMed:24073260).
Promotes cell death through interaction with BCL2L1 that releases and activates BAX (PubMed:21567405).
Biological Process
Antimicrobial humoral response Source: Reactome
Cell morphogenesis Source: Alzheimers_University_of_Toronto
Central nervous system myelin maintenance Source: Alzheimers_University_of_Toronto
Chaperone-mediated protein complex assembly Source: Alzheimers_University_of_Toronto
Chaperone-mediated protein folding Source: UniProtKB
Chaperone-mediated protein transport involved in chaperone-mediated autophagy Source: ARUK-UCL
Complement activation Source: ProtInc
Complement activation, classical pathway Source: UniProtKB-KW
Immune complex clearance Source: UniProtKB
Innate immune response Source: UniProtKB-KW
Intrinsic apoptotic signaling pathway Source: UniProtKB
Lipid metabolic process Source: ProtInc
Microglial cell activation Source: Alzheimers_University_of_Toronto
Microglial cell proliferation Source: Alzheimers_University_of_Toronto
Negative regulation of amyloid-beta formation Source: Alzheimers_University_of_Toronto
Negative regulation of amyloid fibril formation Source: ARUK-UCL
Negative regulation of cell death Source: ARUK-UCL
Negative regulation of cellular response to thapsigargin Source: ARUK-UCL
Negative regulation of cellular response to tunicamycin Source: ARUK-UCL
Negative regulation of intrinsic apoptotic signaling pathway in response to DNA damage Source: BHF-UCL
Negative regulation of protein-containing complex assembly Source: ARUK-UCL
Negative regulation of release of cytochrome c from mitochondria Source: ARUK-UCL
Negative regulation of response to endoplasmic reticulum stress Source: ARUK-UCL
Platelet degranulation Source: Reactome
Positive regulation of amyloid-beta formation Source: Alzheimers_University_of_Toronto
Positive regulation of amyloid fibril formation Source: ARUK-UCL
Positive regulation of apoptotic process Source: UniProtKB
Positive regulation of gene expression Source: ARUK-UCL
Positive regulation of intrinsic apoptotic signaling pathway Source: UniProtKB
Positive regulation of neurofibrillary tangle assembly Source: Alzheimers_University_of_Toronto
Positive regulation of neuron death Source: Alzheimers_University_of_Toronto
Positive regulation of NF-kappaB transcription factor activity Source: UniProtKB
Positive regulation of nitric oxide biosynthetic process Source: Alzheimers_University_of_Toronto
Positive regulation of proteasomal ubiquitin-dependent protein catabolic process Source: UniProtKB
Positive regulation of protein-containing complex assembly Source: ARUK-UCL
Positive regulation of receptor-mediated endocytosis Source: ARUK-UCL
Positive regulation of tau-protein kinase activity Source: Alzheimers_University_of_Toronto
Positive regulation of tumor necrosis factor production Source: Alzheimers_University_of_Toronto
Positive regulation of ubiquitin-dependent protein catabolic process Source: UniProtKB
Protein import Source: Alzheimers_University_of_Toronto
Protein stabilization Source: UniProtKB
Protein targeting to lysosome involved in chaperone-mediated autophagy Source: ARUK-UCL
Regulation of amyloid-beta clearance Source: Alzheimers_University_of_Toronto
Regulation of apoptotic process Source: GO_Central
Regulation of cell population proliferation Source: UniProtKB
Regulation of complement activation Source: Reactome
Regulation of neuronal signal transduction Source: Alzheimers_University_of_Toronto
Regulation of neuron death Source: Alzheimers_University_of_Toronto
Release of cytochrome c from mitochondria Source: BHF-UCL
Response to misfolded protein Source: BHF-UCL
Response to virus Source: UniProtKB
Reverse cholesterol transport Source: BHF-UCL
Cellular Location
Isoform 1: Secreted. Can retrotranslocate from the secretory compartments to the cytosol upon cellular stress.
Isoform 4: Cytoplasm. Keeps cytoplasmic localization in stressed and unstressed cell.
Isoform 6: Cytoplasm. Keeps cytoplasmic localization in stressed and unstressed cell.
Mitochondrion membrane; Mitochondrion; Nucleus; Cytoplasm; Cytosol; Microsome; Endoplasmic reticulum; Perinuclear region; Chromaffin granule. Secreted isoforms can retrotranslocate from the secretory compartments to the cytosol upon cellular stress (PubMed:17451556). Detected in perinuclear foci that may be aggresomes containing misfolded, ubiquitinated proteins (PubMed:20068069). Detected at the mitochondrion membrane upon induction of apoptosis (PubMed:17689225). Under ER stress, a immaturely glycosylated pre-secreted form retrotranslocates from the endoplasmic reticulum (ER)-Golgi network to the cytoplasm to localize in the mitochondria through HSPA5 interaction (PubMed:22689054). ER stress reduces secretion (PubMed:22689054). Under the stress, minor amounts of non-secreted forms accumulate in cytoplasm (PubMed:24073260, PubMed:22689054, PubMed:17451556). Non-secreted forms emerge mainly from failed translocation, alternative splicing or non-canonical initiation start codon (PubMed:24073260, PubMed:12551933).
PTM
Proteolytically cleaved on its way through the secretory system, probably within the Golgi lumen (PubMed:2387851). Proteolytic cleavage is not necessary for its chaperone activity (PubMed:25402950). All non-secreted forms are not proteolytically cleaved (PubMed:24073260). Chaperone activity of uncleaved forms is dependent on a non-reducing envoronment (PubMed:25402950).
Polyubiquitinated, leading to proteasomal degradation (PubMed:17451556, PubMed:19137541). Under cellular stress, the intracellular level of cleaved form is reduced due to proteasomal degradation (PubMed:17451556).
Extensively glycosylated with sulfated N-linked carbohydrates (PubMed:17260971, PubMed:2387851). About 30% of the protein mass is comprised of complex N-linked carbohydrate (PubMed:2387851). Endoplasmic reticulum (ER) stress induces changes in glycosylation status and increases level of hypoglycosylated forms (PubMed:22689054). Core carbohydrates are essential for chaperone activity (PubMed:25402950). Non-secreted forms are hypoglycosylated or unglycosylated (PubMed:24073260).