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Agrin or AGRN is a large protein (proteoglycan) that has a crucial part in the development of neuromuscular junction amid embryogenesis. The protein has an involvement in the collection and aggregation of acetylcholine receptors through synaptogenesis. The agrin gene can be found and expressed in rat embryonic nervous system andmuscle tissue. This Agrin protein is aggregated in the synapses, there it can take part in regeneration & development. The protein binds to receptors on the surface of skeletal muscle.

Hematological and neurological expressed 1 protein (HN1) is a small protein which is extremely preserved among species. HN1 expression is upregulated in regenerating neural tissues, including the axotomized adult rodent facial motor nerve and dedifferentiating retinal pigment epithelial cells of the Japanese newt. HN1 is also expressed in several tissues during embryonic development as well as in regions of the adult brain which display high plasticity.

EFNA1 belongs to the ephrin (EPH) family. The EPH subfamily is the biggest group of receptor protein kinases and they take part in vital nervous system function and development.

Secreted Protein Acidic & Rich in Cysteine (SPARC) protein is coded by the SPARC gene in humans. SPARC is a glycoprotein located in bones that binds to calcium. SPARC is produced by fibroblasts, capillary endothelial cells, platelets and macrophages, mainly in areas of tissue morphogenesis and remodelling. Asides from calcium, SPARC can also bind to collagen.

Opticin also known as OPTC is a member of the class III of the small leucine-rich repeat protein (SLRP) family. Members of this family are usually linked with the extracellular matrix. OPTC is attended in significant quantities in the vitreous of the eye and also localizes to the cornea, iris, ciliary body, optic nerve, choroid, retina, and fetal liver. OPTC might noncovalently bind collagen fibrils and regulate fibril morphology, spacing and organization. OPTC is mapped to a an area of chromosome 1 which is linked with the inherited eye diseases age-related macular degeneration (AMD) and posterior column ataxia with retinosa pigmentosa (AXPC1).

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.

Peptidase Inhibitor 16 (PI16) which a member of the CRISP family, is a putative serine protease inhibitor. PI16 interacts with PSP94/MSMB. PI16 is expressed in the prostate, testis, ovary and intestine. It also concentrates in prostate cancer patient's sera. PI16 may serve as a marker following prostatectomy for prostate cancer.

Furin is a member of the peptidase S8 family. Furin signifies the ubiquitous endoprotease activity within constitutive secretory pathwaysas well as capable of cleavage at the RX (K/R) R consensus motif.Furin is considered to be one of the proteases responsible for the activation of HIV envelope glycoproteins gp160 as well as gp140 and might take part in tumor progression. Among the diseases associated with FURIN are dementia, familial british and plague.

CTK-19 is a member of the keratin family. The keratins are intermediate filament proteins responsible for the structural integrity of epithelial cells and are subdivided into cytokeratins and hair keratins. The type I cytokeratins consist of acidic proteins which are arranged in pairs of heterotypic keratin chains. Unlike its related family members, this smallest known acidic cytokeratin is not paired with a basic cytokeratin in epithelial cells. It is specifically expressed in the periderm, the transiently superficial layer that envelopes the developing epidermis. The type I cytokeratins are clustered in a region of chromosome 17q12-q21.

Ubiquitin-like domain-containing CTD phosphatase 1 (UBLCP1) dephosphorylates 26S nuclear proteasomes, thereby decreasing their proteolytic activity. The dephosphorylation averts assembly of the core and regulatory particles (CP and RP) into mature 26S proteasome.

RELM-beta (Resistin-Like Molecule-beta) is a member of a recently identified family of secreted proteins containing a conserved cystein-rich C-terminus. The RELM family consists of resistin (also called FIZZ3), RELM-alfa (FIZZ1), RELM-beta (FIZZ2) and RELM-gamma. Only resisistin and RELM-beta were found in humans whereas all four RELM family members were identified in rodents.
RELM-beta appears to be produced as a homodimer exclusively by intestinal goblet cells and can be found in high quantities in stool. Remarkably, stool of germ-free mice displaying sterile intestinal tract does not contain RELM-beta until bacterial colonization takes place after pathogen-free mice entered natural environment. Some, but not all, colon carcinoma cell lines secrete RELM-beta into the cell culture supernatant.
The physiological function of RELM-beta is not known. High doses of recombinant RELM-beta showed hyperglycemic effects including lowered glucose disposal and increased hepatic glucose production in mice.

Keratin 8 and 18 (K8/18) are the major components of intermediate filament (IF) proteins of simple or single-layered epithelia.

Angiopoietin-related protein 7 (ANGPTL7), belongs to the angiopoietin-like family of molecules. ANGPTL7 is expressed in the corneal stroma, trabecular meshwork, and sclera. ANGPTL7 production is up-regulated in trabecular meshwork cells by glucocorticoids and TGF-Beta and in cartilage by TNF-alpha.

Dickkopf-related protein 3 (DKK3) belongs to the DKK protein family including Dkk-1, 2, 3 and -4. DKK3 is a 350 amino acid secreted glycoprotein which is comprised of an N-terminal signal peptide and 2 conserved cysteine-rich domains that are separated by a 12 amino acid linker region. DKK3 is involved in embryonic development through its inhibition of the WNT signaling pathway. DKK3 gene expression is decreased in a variety of cancer cell lines and it may act as a tumor suppressor gene.

Vimentin expression in human malignant glioma cells depends on cellular density, algorithms of drug delivery and chemo/radio treatment. Vimentin and detyrosinated microtubules provide structural support for the extensive microtentacles observed in detached tumor cells and a mechanism to promote successful metastatic spread. Primary colorectal carcinomas display aberrant expression of vimentin, and have activated Notch and TGFbeta signaling pathways. Vimentin is a strong arterial substrate for transglutaminases. Transglutaminase-mediated vimentin dimerization results in a novel unifying pathway by which vasodilatory and remodeling responses may be regulated. Ablation of vimentin expression inhibits migration and invasion of colon and breast cancer cell lines. Vimentin is the main intermediate filament protein in mesenchymal cells and is therefore of value in the differential diagnosis of undifferentiated neoplasms.

LAYN, also known as Layilin, contains 1 c-type lectin domain. This protein is receptor for hyaluronate and Interacts with NF2, RDX and TLN1. The C-terminal domain interacts with the N-terminal domain of RDX.

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.

Transferrin is the iron-transport protein of vertebrate serum and donates iron to cells through interaction with a specific membrane receptor, CD71. Transferrin appears to be indispensable for most cells growing in tissue culture.
It is referred to frequently as a growth factor because, in analogy to other growth factor-receptor interactions, proliferating cells express high numbers of transferrin receptors, and the binding of transferrin to their receptors is needed for cells to initiate and maintain their DNA synthesis. Apart from its role as an iron transport protein transferrin acts as a cytokine and has functions that may not be related to its iron-carrying capacity.

Natriuretic Peptide A (NPPA) is a part of the natriuretic peptide family and is involved in cardiovascular homeostasis through regulation of natriuresis, diuresis, and vasodilation. NPPA is synthesized as a great precursor which releases a peptide from the N-terminus with similarity to vasoactive peptide, cardiodilatin, and another peptide from the C-terminus with natriuretic-diuretic activity. In female pregnancy, NPPA is promoting trophoblast invasion and spiral artery remodeling in uterus.

APIP catalyzes the dehydration of methylthioribulose-1-phosphate (MTRu-1-P) into 2,3-diketo-5-methylthiopentyl-1-phosphate (DK-MTP-1-P). APIP has an anti-apoptotic function and inhibits muscle ischemic impairment. APIP inhibits the cytochrome c-dependent and APAF1-mediated cell death.

Defensins form a family of microbicidal and cytotoxic peptides made by neutrophils. Members of the defensin family are highly similar in protein sequence. This gene encodes defensin, beta 103A, which has broad spectrum antimicrobial activity and may play an important role in innate epithelial defense.

Natriuretic Peptide Precursor B acts as a cardiac hormone with a variety of biological actions including natriuresis,vasorelaxation,diuresis and inhibition of renin and aldosterone secretion. BNP plays a key role in cardiovascular homeostasis. BNP also helps restore the body's salt and water balance andimproves heart function.

Oncostatin M is a member of a cytokine family that includes leukemia-inhibitory factor, granulocyte colony-stimulating factor, and interleukin 6. This gene encodes a growth regulator which inhibits the proliferation of a number of tumor cell lines. It regulates cytokine production, including IL-6, G-CSF and GM-CSF from endothelial cells.

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, 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.