Search results

Clusterin also known as 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 5 disulfide bridges and are flanked by 2 predicted coiled-coil a-helices and 3 predicted amphipathic a-helices.
Across a broad range of species clusterin shows a high degree of sequence homology ranging from 70% -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.
Clusterin is up/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.

Crystallin, Mu (CRYM) is a taxon-specific crystallin protein which binds NADPH and has sequence similarity to bacterial ornithine cyclodeaminases. CRYM doesn’t perform a structural role in lens tissue; instead CRYM binds thyroid hormone for possible regulatory or developmental roles. CRYM gene mutations are linked with autosomal dominant non-syndromic deafness. CRYM specifically catalyzes the reduction of imine bonds in brain substrates which may include cystathionine ketamine and lanthionine ketamine.

Cathepsin-E also known as CTSE is a gastric aspartyl protease which functions as a disulfide-linked homodimer. CTSE belongs to the peptidase C1 family; furthermore it has specificity similar to pepsin A and cathepsin D. CTSE is an intracellular proteinase which does not seem to be involved in the digestion of dietary protein and is found in the uppermost concentration in the surface of epithelial mucus-producing cells of the stomach. CTSE is the first aspartic proteinaseexpressed in the fetal stomach and is discovered in more than half of gastric cancers. For that reason CTSE is anoncofetal antigen. In addition, transcript variants utilizing alternative polyadenylation signals and two transcript variantsencoding different isoforms exist for this gene.

Chemokine (C-X-C motif) ligand (CXCL7) is a small cytokine belonging to the CXC chemokine family. It is a protein that is released in large amounts from platelets following their activation. It stimulates various processes including mitogenesis, synthesis of extracellular matrix, glucose metabolism and synthesis of plasminogen activator.

The cytokine Macrophage migration inhibitory factor (MIF) has been identified to be secreted by the pituitary gland and the monocyte/macrophage and to play an important role in endotoxic shock. MIF has the unique property of being released from macrophages and T cells in response to physiological concentrations of glucocorticoids. The secretion of MIF is tightly regulated and decreases at high, anti-inflammatory steroid concentration.

CAMP belongs to the antimicrobial peptide family, contains highly conserved N-terminal signal peptide, a cathelin domain and a structurally variable cationic antimicrobial peptide that produced by extracellular proteolysis from the C-terminus. CAMP has numerous functions besides the antimicrobial activity such as: cell chemotaxis, immune mediator induction and inflammatory response regulation.

Glycinin Ara h 3 is a seed storage protein, 11 S globulin and trypsin inhibitor from peanut. Each subunit of the hexamer is composed of an acidic and a basic chain derived from a single precursor and linked by a disulfide bond. Ara h 3 and Ara h 4 are isoforms. Glycinin is the source of sulfur-containing amino acids in seed meals and it exists in the seeds of many leguminous and non-leguminous plants.

CTLA-4 is a member of the immunoglobulin superfamily and encodes a protein which transmits an inhibitory signal to T cells. The protein contains a V domain, a transmembrane domain, and a cytoplasmic tail. Alternate transcriptional splice variants, encoding different isoforms, have been characterized. The membrane-bound isoform functions as a homodimer interconnected by a disulfide bond, while the soluble isoform functions as a monomer. Mutations in this gene have been associated with insulin-dependent diabetes mellitus, Graves disease, Hashimoto thyroiditis, celiac disease, systemic lupus erythematosus, thyroid-associated orbitopathy, and other autoimmune diseases.

PPIF is a part of the peptidyl-prolyl cis-trans isomerase (PPIase) family. PPIF accelerates the folding of proteins. It catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides. PPIF is key component of the mitochondrial permeability transition pore in the inner mitochondrial membrane. Activation of this pore is thought to be involved in the induction of apoptotic and necrotic cell death.

Chemokine (C-C motif) ligand 19 (CCL19) is a small cytokine belonging to the CC chemokine family that is also known as EBI1 ligand chemokine (ELC) and macrophage inflammatory protein-3-beta (MIP-3-beta). CCL19 is expressed abundantly in thymus and lymph nodes, with moderate levels in trachea and colon and low levels in stomach, small intestine, lung, kidney and spleen. The gene for CCL19 is located on human chromosome 9. This chemokine elicits its effects on its target cells by binding to the chemokine receptor chemokine receptor CCR7. It attracts certain cells of the immune system, including dendritic cells and antigen-engaged B cells.

SLAMF7 belongs to the CS2 family of cell surface receptors. SLAMF7 is a single-pass type 1 membrane protein, SLAMF7 Isoform 1 mediates NK cell activation via aSH2D1A-independent extracellular signal-regulated ERK-mediated pathway. SLAMF7 functions in lymphocyteadhesion. Furthermore, SLAMF7 can exert activating of inhibitory influences on cells of the immune system depending on cellular context as well as the availability of effector proteins.

Listeriolysin O (aka LLO) is a hemolysin produced by Listeria monocytogenes bacteria, the pathogen responsible for causing listeriosis. The toxin may be regarded as a virulence factor, since it is crucial for the virulence of L. monocytogenes. LLO is a single polypeptide protein encoded by the hlyA gene and composed of 529 residues. LLO is a thiol-activated cholesterol-dependent pore forming toxin protein; therefore, it is activated by reducing agents and inhibited by oxidizing agents. Still, LLO differs from other thiol-activated toxins, as its cytolytic activity is maximized at a pH of 5.5. Inside the acidic phagosomes (average pH ~ 5.9) of cells that have phagocytosed L. monocytogenes, LLO is selectively activated by maximizing activity at a pH of 5.5. Following the phagosome lysis by LLO, the bacterium breaks out into the cytosol, where it is able to grow intracellularly, and the toxin has reduced activity in the more basic cytosol. Thus, LLO permits L. monocytogenes to break out from the phagosomes into the cytosol without harming the plasma membrane of the infected cell, which allows the bacteria to live intracellularly, where they are sheltered from extracellular immune system factors such as the complement system and antibodies. LLO also brings about dephosphorylation of histone H3 and deacetylation of histone H4 in the early phases of infection, before entry of L. monocytogenes into the host cell. The pore-forming activity is not implicated in causing the histone modifications. The modifications of the histones affect the down regulation of genes encoding proteins involved in the inflammatory response. Therefore, LLO may be significant in subverting the host immune response to L. monocytogenes. At its NH2-terminus it possesses a 25 residues long typical signal sequence excited during the secretion process. Moreover, in its NH2-terminus there is also a 19 amino acids PEST- like sequence that may target this toxin for degradation. The PEST-like sequence found in LLO and is considered crucial for virulence, given that mutants lacking the sequence lysed the host cell. Nevertheless, contrary to PEST's supposed role in protein degradation, evidence implies that the PEST-like sequence may control LLO production in the cytosol rather than increase degradation of LLO.

Matrix metalloproteinases are a family of zinc and calcium-dependent endopeptidases that break down extracellular matrix proteins. The MMP9 is secreted as a 92kDa zymogen. Cleavage of ProMMP-9 results in the active enzyme, having a molecular weight of approximately 82kDa. MMP9 is composed of the following domains: a gelatin-binding domain consisting of three fibronectin type II units, a catalytic domain containing the zinc-binding site, a proline-rich type V collagen-homologous domain and a hemopexin-like domain. MMP9 is produced by the several cell types: monocytes, macrophages, neutrophils, keratinocytes, fibroblasts, osteoclasts and endothelial cells. MMP9 is involved in inflammatory responses, tissue remodeling, wound healing, tumor growth and metastasis. MMP9 may also play an important part in local proteolysis of the extracellular matrix and in leukocyte migration, as well as in bone osteoclastic resorption. MMP9 cleaves type IV and type V collagens into large C-terminal three quarter fragments and shorter N-terminal one quarter fragments. MMP9 can also degrade fibronectin but not laminin or Pz-peptide.
MMP9 defects may be a cause of susceptibility to intervertebral disc disease (IDD), also known as lumbar disk herniation (LDH).

Tri a 14.0101 is a non-specific lipid transfer protein and a major wheat allergen. Those who are sensitive to this allergen may have baker’s asthma, a frequent occupational allergic disease caused mainly by inhalation of cereal flour, especially wheat flour. Tri a 14.0101 consists of 4 helical fragments and irregular C-terminal regions which are highly stable to heat treatment and proteolytic attack.

Cystatins are a superfamily of cysteine proteinase inhibitors found in both plants and animals. They comprise a group of proteinase inhibitors, widely distributed in tissues and body fluids, and form tight complexes with cysteine proteases such as cathepsin B, H, L and S. Cystatin C, a secreted molecule of this family, is of interest from biochemical, medicine and evolutionary points of view. Cystatin C, with molecular weight of 13260 Da, is composed of 120 amino acids, lacks carbohydrate and has two disulfide bridges located near the carboxyl terminus. Cystatin C is increased in patients with malignant diseases, and is related to the insufficiency of renal function and appears to be a better marker than creatinine. On the other hand, low levels of cystatin C involve cause the breakdown of the elastic laminae and, subsequently, the atherosclerosis and abdominal aortic aneurysm.

Cathepsin-A (CTSA) is a protective protein which is crucial for both the activity of beta-galactosidase and neuraminidase, CTSA associates with these enzymes and exerts a protective function required for their stability and activity. The CTSA protein is also a carboxypeptidase and can deamidate tachykinins. CTSA is a component of the lysosomal multienzyme complex along with beta-galactosidase and sialidase Neu1. CTSA is a multicatalytic enzyme with deamidase and esterase in addition to carboxypeptidase activities.

Decorin (DCN) is a small cellular or pericellular matrix proteoglycan which is closely related in structure to biglycan protein. Decorin is a secreted protein which binds to collagen and fibronectin in extracellular matrix. Decorin appears in different glycoforms, substituted with chondroitin sulfate or dermatan sulfate consistent with the original tissue. DCN contains one attached glycosaminoglycan chain. Decorin influences the rate of fibril formation. Decorin is capable of suppressing the growth of various tumor cell lines. DCN gene defects cause corneal dystrophy. The DCN gene is a candidate gene for Marfan syndrome.

CD47, functions in cell adhesions by performing as an adhesion receptor for THBS1 on platelets, furthermore CD47 plays a role in the modulation of integrins. In addition, CD47 takes a vital part in memory formation as well as synaptic plasticity in the hippocampus. Receptor for SIRPA avoids maturation of immature dendritic cells and inhibits cytokine production by mature dendritic cells. CD47 prevents premature elimination of red blood cells, and it is also implicated in membrane permeability changes induced following virus infection.

Crystallin Zeta, also known as CRYZ, Binds NADP and participates in a one-electron transfer process. CRYZ takes part in the detoxification of xenobiotics and Interacts with (AU)-rich elements (ARE) in the 3'-UTR of target mRNA species. CRYZ improves the mRNA coding for BCL2.

E-selectin which is also called Endothelial leukocyte adhesion molecule 1, ELAM1, ELAM belongs to a family of divalent cation-dependent carbohydrate-binding glycoproteins or adhesion molecules. Eselectin is expressed on the surface of endothelial cells and mediates the interaction of leukocytes and platelets with endothelial cells during an inflammatory response. E-selectin is present in single copy in the human genome and contains 14 exons spanning about 13 kb of DNA.

NCR2 is a member of the natural cytotoxicity receptor (NCR) family and holds 1 immunoglobulin-like (Ig-like) domain. NCR2 cooperates with TYROBP/DAP12 and is specifically expressed by activated NK cells and by in vitro cultured TCRg/d lymphoid cells. NCR2 is a cytotoxicity-activating receptor which induces the amplified efficiency of activated natural killer (NK) cells to mediate tumor cell lysis.

Chemokine (C-X-C motif) ligand 5 (CXCL5) is a small cytokine belonging to the CXC chemokine family that is also known as epithelial-derived neutrophil-activating peptide 78 (ENA-78). It is produced following stimulation of cells with the inflammatory cytokines interleukin-1 or tumor necrosis factor-alpha. Expression of CXCL5 has also been observed in eosinophils, and can be inhibited with the type II IFN. This chemokine stimulates the chemotaxis of neutrophils possesses angiogenic properties. It elicits these effects by interacting with the cell surface chemokine receptor CXCR2. The gene for CXCL5 is encoded on four exons and is located on human chromosome 4 amongst several other CXC chemokine genes. CXCL5 has been implicated in connective tissue remodelling.

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.