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Clusterin also named Apolipoprotein J (APO-J) is a 75-80 kD disulfide-linked heterodimeric protein containing about 30% of N-linked carbohydrate rich in sialic acid but truncated forms targeted to the nucleus have also been identified.
The precursor polypeptide chain is cleaved proteolytically to remove the 22-mer secretory signal peptide and subsequently between residues 227/228 to generate the a and b chains. These are assembled in anti-parallel to give a heterodimeric molecule in which the cysteine-rich centers are linked by five disulfide bridges and are flanked by two predicted coiled-coil a-helices and three predicted amphipathic a-helices.
Across a broad range of species clusterin shows a high degree of sequence homology ranging from 70% to 80%. It is nearly ubiquitously expressed in most mammalian tissues and can be found in plasma, milk, urine, cerebrospinal fluid and semen.
It is able to bind and form complexes with numerous partners such as immunoglobulins, lipids, heparin, bacteria, complement components, paraoxonase, beta amyloid, leptin and others. Clusterin has been ascribed a plethora of functions such as phagocyte recruitment, aggregation induction, complement attack prevention, apoptosis inhibition, membrane remodeling, lipid transport, hormone transport and/or scavenging, matrix metalloproteinase inhibition.
A genuine function of clusterin has not been defined. One tempting hypothesis says that clusterin is an extracellular chaperone protecting cells from stress induced insults caused by degraded and misfolded protein precipitates.
Clusterin is up- or down regulated on the mRNA or protein level in many pathological and clinically relevant situations including cancer, organ regeneration, infection, Alzheimer disease, retinitis pigmentosa, myocardial infarction, renal tubular damage, autoimmunity and others.

Platelet factor-4 is a 70-amino acid protein that is released from the alpha-granules of activated platelets and binds with high affinity to heparin. Its major physiologic role appears to be neutralization of heparin-like molecules on the endothelial surface of blood vessels, thereby inhibiting local antithrombin III activity and promoting coagulation. As a strong chemoattractant for neutrophils and fibroblasts, PF4 probably has a role in inflammation and wound repair. Oncostatin-A is a member of the CXC chemokine family. Human PF4 is used for the proof of heparin-induced thrombocytopenia. Furthermore it is used as an inhibitor in the angiogenesis during tumor therapy.

FKBP1A is a 12kDa protein initially discovered on an immune cells on the basis of its capability to bind as well as mediate the intracellular effect of the immunosuppressant FK506. FKBP1A is also known to mediate the action of Rapamycin-immunosuppressive agent. FKBP1A is part of the family of immunophilins, which have in common high affinity for immunosuppressant drugs and a peptidyl-prolyl cis-trans isomerase (PPIase). Activity which participates in folding of proline-containing protein. In the absence of immunosuppressive ligands, FKBP1A is involved in intracellular calcium regulation by associating with 3 types of Ca2+ release channel complexes: skeletal ryanodine receptors, cardiac ryanodine receptors and the inositol 1,4,5-triphosphate receptor. FKBP1A also interact with TGF-beta type I receptor exerting an inhibitory effect on the TGF-beta signaling pathway. FKBP12 plays a role in modulation of ryanodine receptor isoform-1 (ryr-1), a component of the calcium release channel of skeletal muscle sarcoplasmic reticulum. FKBP1A increase the folding of proteins and catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides.

Chemokine (C-X-C motif) ligand 10 (CXCL10) is a small cytokine belonging to the CXC chemokine family. CXCL10 is secreted by several cell types in response to IFN-?. These cell types include monocytes, endothelial cells and fibroblasts. CXCL10 has been attributed to several roles, such as chemoattraction for monocytes and T cells, promotion of T cell adhesion to endothelial cells, antitumor activity, and inhibition of bone marrow colony formation and angiogenesis. The gene for CXCL10 is located on human chromosome 4 in a cluster among several other CXC chemokines. This chemokine elicits its effects by binding to the cell surface chemokine receptor CXCR3. The three-dimensional crystal structure of this chemokine has been determined under 3 different conditions to a resolution of up to 1.92A.

Josephin-1 (JOSD1) has minimal protease activity towards poly-ubiquitin chains (in vitro). JOSD1 functions as a deubiquitinating enzyme. Ubiquitin-binding sites in the Josephin domain are a factor in ubiquitin chain binding and cleavage.

ARL4A is related Specifically to ARL6 and ARL7 and belongs to the ARF-like protein (ARL) subfamily of small GTPases. However, unlike ARFs, ARL4 does not activate the cholera toxin ADP-ribosyltranferase. ARL4A takes part in neurogenesis during embryonic development and somitogenesis in the early stages of adult spermatogenesis.

ARL1 is part of the ARL (ADP-ribosylation factor-like) family of proteins, which are structurally associated to ADP-ribosylation factors (ARFs). ARFs, described as activators of cholera toxin (CT) ADP-ribosyltransferase activity, control intracellular vesicular membrane trafficking, and stimulate a phospholipase D (PLD) isoform.
ARL1 is a weak stimulator of PLD and CT in a phospholipid dependent manner.
ARL1 is a GTP-binding protein that has low efficiency as allosteric activator of the cholera toxin catalytic subunit, an ADP-ribosyltransferase. ARL1 is involved in the Golgi apparatus.

a-Synuclein (amino acids 1-140), an acidic neuronal protein of 140 amino acids, is extremely heat-resistant and is natively unfolded with an extended structure primarily composed of random coils. a-synuclein has been suggested to be implicated in the pathogenesis of Parkinson’s disease and related neurodegenerative disorders, and more recently, to be an important regulatory component of vesicular transport in neuronal cells. Moreover, recent studies have shown that a-synuclein has chaperone activity and that this activity is lost upon removing its C-terminal acidic tail (amino acids 96-140).

Lxn also known as Latexin is a member of the protease inhibitor I47 (latexin) family. Lxn's function is hardly reversible, non-competitive, as well as potent inhibitor of CPA1, CPA2 and CPA4. Furthermore, Lxn plays a role in inflammation. Among the diseases associated with LXN are endocervicitis and listeriosis.

Otubain 1 (OTUB1) belongs to the ovarian tumor (OUT) superfamily of predicted cysteine proteases and inhibits cytokine gene transcription in the immune system through its interaction with a ubiquitin protease and E3 ubiquitin ligase. OTUB1 is a highly specific ubiquitin iso-peptidase, it cleaves ubiquitin from branched poly-ubiquitin chains but not from ubiquitinated substrates. OTUB1 is believed to work in specific ubiquitin-dependent pathways, possibly by providing an editing function of polyubiquitin chain growth. OTUB1 is a hydrolase that removes conjugated ubiquitin from proteins in vitro and may therefore have a significant regulatory role in the level of protein turnover by preventing degradation. Additionally, OTUB1 is a regulator of T-cell anergy, a phenomenon that occurs when T-cells are rendered impassive to antigen re-challenge and no longer respond to their cognate antigen. OTUB1 acts via its interaction with RNF128/GRAIL, which is an essential inductor of CD4 T-cell anergy.

E3 ubiquitin ligase RNF4 (RNF4) contains a RING finger motif and functions as a transcription regulator. RNF4 interacts with, and inhibits the activity of, TRPS1, a transcription suppressor of GATA-mediated transcription. Transcription repressor ZNF278/PATZ also interacts with the RNF4 protein thus reducing the enhancement of androgen receptor-dependent transcription mediated by RNF4. RNF4 is broadly expressed at low levels in many tissues and highly expressed in the testis.

Cold shock domain-containing protein C2 (CSDC2) is RNA-binding factor that binds specifically to the very 3'-UTR ends of both histone H1 and H3. 3 mRNAs encompass the polyadenylation signal. The CSDPs (cold shock domain containing proteins) are one group of the evolutionarily conserved nucleic acid-binding proteins extensively distributed in bacteria, plants, animals, and involved in a variety of cellular processes, including adaptation to low temperature, cellular growth, nutrient stress and stationary phase. CSDC2 has a central role in the negative regulation of histone variant synthesis in the developing brain.

Dysbindin domain-containing protein 2 (DBNDD2) is a member of the dysbindin family. DBNDD2 regulates the activity of casein kinase-1 and inhibits CSNK1D autophosphorylation (in vitro). DBNDD2 also interacts with CSNK1D and CSNK1E. DBNDD2 is detected in brain.

HRAS is part of the Ras oncogene family, whose members are related to the transforming genes of mammalian sarcoma retroviruses. The products encoded by these genes participate in signal transduction pathways. These proteins can bind GTP and GDP, and they have intrinsic GTPase activity. HRAS go trough a continuous cycle of de- and re-palmitoylation, which mediates its rapid exchange between the plasma membrane and the Golgi apparatus. Mutations in HRAS result in Costello syndrome, a disease characterized by increased growth at the prenatal stage, growth deficiency at the postnatal stage, predisposition to tumor formation, mental retardation, skin and musculoskeletal abnormalities, distinctive facial appearance and cardiovascular abnormalities. Defects in this HRAS gene are implicated in a range of cancers, including bladder cancer, follicular thyroid cancer, and oral squamous cell carcinoma.

Biglycan (BGN) is a small cellular or pericellular matrix proteoglycan which takes part in assembly of collagen fibrils and muscle regeneration. BGN is closely correlated in structure to two other small proteoglycans, decorin and fibromodulin. BGN interacts with several proteins involved in muscular dystrophy, including alpha-dystroglycan, alpha- and gamma-sarcoglycan and collagen VI. BGN is also critical for the assembly of the dystrophin-associated protein complex.

NTRK1 plays a role in the development and survival of nerve cells (neurons), specifically those that transmit dataregarding senses such as touch, pain and temperatureie. sensory neurons. NTRK1 protein is located on surface cells, mainly such as sensory neurons. NTRK1 acts as a kinase enzyme that alters the activity of different proteins by adding anoxygen cluster and phosphorus atoms at precise positions ie. phosphorylation. NTRK1 activated by nerve growth factor beta which binds to it and signals the NTRK1 protein to phosphorylate itself. Post autophosphorylation, the activated NTRK1 protein phosphorylates other proteins which is required for cell growth and survival.

Mediator Complex Subunit 20 (MED20) is a subunit of the Mediator complex, which is a multiprotein coactivator of RNA transcription that interacts with DNA-bound transcriptional activators, RNA polymerase II, and general initiation factors. The Mediator functions as a link to transmit information from gene-specific regulatory proteins to the basal RNA polymerase II transcription apparatus. Mediator is recruited to promoters by direct interactions with regulatory proteins and functions as a scaffold for the compilation of a functional preinitiation complex with RNA polymerase II and the general transcription factors.

RAB5C is a part of the Ras-related protein family. Members of the Rab protein family are small GTPases of the Ras superfamily guarantee reliability in the process of docking and fusion of vesicles with their right acceptor compartment.

RAB34 protein which regulates a fast endocytic recycling pathway is restricted to the plasma membrane and endocytic compartments. RAB34 takes part in protein transport, specifically the redistribution of lysosomes to the peri-Golgi region. In fibroblasts, RAB34 protein was co-localized with actin to the membrane ruffles and membranes of moderately large vesicles close to the ruffles.

Adipocyte fatty acid binding protein FABP4 is a 15 kDa member of the intracellular fatty acid binding protein (FABP) family, which is known for the ability to bind fatty acids and related compounds (bile acids or retinoids) in an internal cavity. FABP4 is expressed in a differentiation-dependent fashion in adipocytes and is a critical gene in the regulation of the biological function of these cells.
In mice, targeted mutations in FABP4 provide significant protection from hyperinsulinemia and insulin resistance in the context of both dietary and genetic obesity. Adipocytes obtained from FABP4-deficient mice also have reduced efficiency of ipolysis in vitro and in vivo, and these mice exhibited moderately improved systemic dyslipidemia. Recent studies also demonstrated FABP4 expression in macrophages upon differentiation and activation. In these cells, FABP4 modulates inflammatory responses and cholesterol ester accumulation, and total or macrophage-specific FABP4 deficiency confers dramatic protection against atherosclerosis in the apoE-/- mice. These results indicate a central role for FABP4 in the development of major components of the metabolic syndrome through its distinct actions in adipocytes and macrophages.

Regulated upon Activation, Normal T-cell Expressed, and Secreted or RANTES is an 8 kDa protein classified as a chemotactic cytokine or chemokine. It has recently been renamed CCL5. RANTES is chemotactic for T cells, eosinophils and basophils and plays an active role in recruiting leukocytes into inflammatory sites. With the help of particular cytokines (i.e. IL-2 and IFN-?) that are released by T cells, RANTES also induces the proliferation and activation of certain natural killer (NK) cells to form CHAK (CC-Chemokine-activated killer) cells. It is also a HIV-suppressive factor released from CD8+ T cells. This chemokine has been localized to chromosome 17 in humans.

Rab2B is a member of the small GTPase superfamily, whose members are nontransforming monomeric GTP-binding proteins of the Ras superfamily and contain 4 highly conserved regions involved in GTP binding and hydrolysis. Rab proteins are prenylated, membrane-bound proteins engaged in vesicular fusion and trafficking.

Advanced Glycosylation End Product-Specific Receptor or RAGE is an immunoglobulin, part of the immunoglobulin transmembrane proteins family. RAGE moderates interactions between advanced glycosylation end products, also known as AGE. These signaling has a crucial part in the regulation of TNFalpha,oxidative stress, endothelial dysfunction in type 2 diabetesproduction and expression. RAGE helps the translocation of ABPP (amyloid-beta peptide) through the membrane of cells to the intracellular area in the cortical neurons.

SRP54 is a 54-kDa subunit of the signal recognition particle (SRP), a cytoplasmic ribonucleoprotein complex which leads the translocation of newly synthesized secretory proteins from the polysome to the endoplasmic reticulum. SRP is composed of six polypeptides and a tRNA-like molecule known as 7SL RNA. SRP54 is a GTP-binding protein that directly binds the signal sequences of nascent secretory and membrane proteins. Anti-SRP autoantibodies take place in patients with an autoimmune chronic muscle inflammation called polymyositis. These auto-antibodies predominantly recognize the SRP54 subunit and in addition are able to immunoprecipitate several of the SRP subunits and the RNA component. Nearly 5% of myositis patients are positive for anti-SRP autoantibodies, increasing to 18% in the subgroup of Jo-1 autoantibody-negative patients. The classic 'anti-SRP syndrome' is a severe form of polymyositis in which the myositic inflammation is acute and aggressive onset, with common myalgias and cardiac involvement. Normally there is a poor reaction to therapy with a 5-year survival rate of about 25%.