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Matrix metalloproteinase-14 (MMP14), is a membrane-anchored zinc-binding endopeptidase which is expressed at the leading edge of different invasive carcinomas and also promotes tumor cell invasion through degradation of the extracellular matrix. MMP14 takes a vital part in extracellular matrix, ECM, remodeling by having the capability to degrade type I collagen, activate pro-MMP-2 and process cell adhesion molecules for instance CD44 and integrin alpha V. MMP14 is a key enzyme in many physiological as well as pathological processes for example angiogenesis & tumor invasion.

AFP is normally synthesized in the liver, intestinal tract, and yolk sac of the fetus. Antibody to AFP has been shown to be useful in detecting hepatocellular carcinomas (HCC) and germ cell neoplasms, especially yolk sac tumors.

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 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.

Sclerostin (SOST) is a secreted glycoprotein with a C-terminal cysteine knot-like (CTCK) domain and sequence similarity to the DAN (differential screening-selected gene aberrative in neuroblastoma) family of bone morphogenetic protein (BMP) antagonists. Sclerostin functions as a negative regulator of bone growth, by inhibiting bone formation. SOST is widely expressed at low levels, with highest levels in the bone, cartilage, kidney, liver, bone marrow and primary osteoblasts differentiated for 21 days. SOST gene defects cause sclerosteosis and bone dysplasia.

C3 is central to the activation of all 3 pathways of complement activation. Initiation of each pathway generates proteolytic enzyme complexes which binds the target surface. These enzymes cleave a peptide bond in C3 releasing the anaphylatoxin C3a and activating C3b. Most of the C3 activated during complement activation never attaches to the surface due to its thioester reaction with water forming fluid phase C3b which is rapidly inactivated by factors H and I forming iC3b. Surface-bound C3b is necessary in all 3 pathways for efficient activation of C5 and formation of C5b-9 complexes that lyse the target cell membrane.

Macrophage Inflammatory Proteins (MIP) belong to the family of chemotactic cytokines known as chemokines. In humans, there are two major forms, MIP-1a and MIP-1b that are now officially named CCL3 and CCL4 respectively. Both are major factors produced by macrophages after they are stimulated with bacterial endotoxins. They activate human granulocytes (neutrophils, eosinophils and basophils) which can lead to acute neutrophilic inflammation. They also induce the synthesis and release of other pro-inflammatory cytokines such as interleukin 1 (IL-1), IL-6 and TNF-a from fibroblasts and macrophages. The genes for CCL3 and CCL4 are both located on human chromosome 17.

AN1-type zinc finger protein 1 isoform a (ZFAND1) is a member of the Zinc-finger proteins. Proteins from this family contain DNA-binding domains and have an extensive variety of functions, most of which encompass some form of transcriptional activation or repression. ZFAND1 is a 268 amino acid protein, which contains two AN1-type zinc fingers that are repeatedly found in proteins which contain an ubiquitin-like domain and for that reason have a role in the ubiquitination pathway ZFAND1 is comprised of 6 conserved cysteines and 2 histidines and have a dimetal (zinc)-bound alpha/beta fold. As a result of alternative splicing events two isoforms of ZFAND1 are produced.

Prolactin inducible protein (PIP) is a 17kDa glycoprotein existing in human seminal plasma. PIP is synthesized as a 146 amino acid long polypeptide exhibiting high sequence similarity with mouse submaxillary gland with a single glycosylation site. The precise biological functions of PIP are still ambiguous but various functions have been assigned to PIP due its existence at high concentration in biological fluids. PIP binds to various proteins such as fibrinogen, actin, keratin, myosin and tropomyosin. PIP is also expressed in pathological conditions of the mammary gland and in some exocrine tissues, such as the lacrimal, salivary and sweat glands. Due to PIP’s association with secretory cell differentiation, it has been used in diagnostic evaluation of tumors of breast, salivary gland, and skin.

Neuropilin 1 (Nrp1) is a transmembrane glycoprotein which functions as a co-receptor for several extracellular ligands including class III/IV semaphorins, some isoforms of vascular endothelial growth factor and transforming growth factor beta. Nrp1 binds vascular endothelial growth factor (VEGF)-A and is believed to serve as a coreceptor for kinase insert domain-containing receptor (KDR) by connecting with KDR and enhancing VEGF signaling. Nrp1 is a marker of regulatory T cells.

PPIases catalyze the cis-trans isomerization of proline imidic peptide bonds in oligopeptides and accelerate the folding of proteins. Cyclophilin-A is a cyclosporin binding-protein and may play a role in cyclosporin A-mediated immunosuppression. Cyclophilin-A can also interact with several HIV proteins, including p55 gag, Vpr, and capsid protein, and has been shown to be necessary for the formation of infectious HIV virions. Multiple pseudogenes that map to different chromosomes have been reported.

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.

Meprin A subunit alpha (MEP1A) is a single-pass type I membrane protein which is a member of the peptidase M12A family. MEP1A is abundantly expressed in the kidney and intestinal epithelial cells, is secreted into the urinary tract and intestinal lumen, and found in leukocytes and cancer cells under certain conditions. MEP1A is capable of proteolytically degrading extracellular matrix proteins, proteolytically processing bioactive proteins, and has a role in inflammatory processes.

Stress-Induced Protein SAM22 (Gly m 4.0101) causes an allergic reaction in humans. Gly m 4 is the main soy allergen for patients allergic to birch pollen with soy allergy.

Calbindin 1 (CALB1) is a calcium binding protein that is a member of the troponin C superfamily. CALB1 plays a vital role in calcium regulation (including calcium transport and uptake, calcification of bone and teeth) and calcium associated signaling in neurons and transiently in embryological development. CALB1 also has a role in protecting neurons from apoptotic cell death. CALB1 buffers cytosolic calcium and may stimulate a membrane Ca2+-ATPase and a 3',5'-cyclic nucleotide phosphodiesterase. The biological function of CALB1 seems to be tied to the redox state of its five cysteine residues.
CALB1 has 4 active calcium-binding domains, and 2 modified domains that seemingly have lost their calcium-binding ability. CALB1 is expressed in neural tissues. In the brain, the CALB1 synthesis is independent of vitamin-D-derived hormones.
Disregulation of the CALB1 is associated with epilepsy, amyotrophic lateral sclerosis, Huntington's disease. The neurons in brains of Huntington disease patients are calbindin-depleted.

Growth arrest and DNA Damage-Inducible Protein (GADD45A) binds both Cdks and PCNA. GADD45A is involved in DNA replication and repair. GADD45A stimulates DNA excision repair in vitro and inhibits entry of cells into S phase. GADD45A may serve as a link between p53-dependent cell cycle checkpoint and DNA repair. The GADD45A gene belongs to a group of genes whose transcript levels are increased following stressful growth arrest conditions and treatment with DNA-damaging agents. GADD45A responds to environmental stresses by mediating activation of the p38/JNK pathway via MTK1/MEKK4 kinase. GADD45A binds to proliferating cell nuclear antigen.

MAGEA5 belongs to the MAGEA gene family which encodes proteins with 50 to 80% sequence identity to each other. The promoters and first exons of the MAGEA genes are variable, which signify that the presence of this gene family enables the same role to be expressed under diverse transcriptional controls. The MAGEA genes are clustered at chromosomal location Xq28. They are associated with several hereditary disorders, like dyskeratosis congenita. MAGEA5 gene encodes a protein which is C-terminally truncated compared to other family members, and can be alternatively interpreted to be a pseudogene.

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).

MYL9 is one of the numerous regulatory myosin light chains. Myosin which is a structural component of the muscle consists of 2 heavy chains and 4 light chains. MYL9 is a myosin light chain regulates muscle contraction by modulating the ATPase activity of myosin heads. MYL9 binds calcium and is activated by myosin light chain kinase. Regulatory myosin light chains regulate contraction in smooth muscle and non-muscle cells via phosphorylation by MLCK (myosin light chain kinase). Phosphorylation of regulatory myosin light chains is catalyzed by MLCK in the presence of calcium and calmodulin and it increases the actin-activated myosin ATPase activity, thus regulates the contractile activity.

XIAP Associated Factor 1 (XAF1) is a protein which binds to and counteracts the inhibitory effect of a member of the IAP (inhibitor of apoptosis) protein family. IAP proteins bind to and inhibit caspases which are activated in the course of apoptosis. The ratio of IAPs and proteins which interfere with their activity, such as the XAF1 protein, influence the progress of the apoptosis signaling pathway. Additionally, XAF1 inhibits anti-caspase activity of BIRC4. XAF1 induces cleavage and inactivation of BIRC4 independent of caspase activation. Furthermore, XAF1 mediates TNF-alpha-induced apoptosis and is involved in apoptosis in trophoblast cells.

WIF1 binds to wnt proteins and inhibits their activities. WIF1 plays a role in mesoderm segmentation. WNT proteins are extracellular signaling molecules that take part in the control of embryonic development & cancer. WIF1 protein contains a WNT inhibitory factor (WIF) domain and 5 epidermal growth factor (EGF)-like domains. WIF1 takes part in mesoderm segmentation. WIF1 protein is found to be present in fish, amphibia and mammals. WIF1 is a recurrent target in human salivary gland oncogenesis. Downregulation of WIF1 takes part in the development and progression of pleomorphic adenomas. WIF1 is a tumor suppressor, specifically in nonfunctioning pituitary tumors.

Matrix Metalloproteinase-13 (MMP-13) is an enzyme that is a member of the MMP extracellular protease family. Extracellular protease enzymes, by virtue of their broad substrate specificities1, play a role in both normal and disease states of tissue proliferation. Among the targets of MMP-13 are collagen, gelatin, entactin, pro-TNF-a, and chemokine SDF-11-4.
MMP-13 is found in its latent form as a 52-56 kDa glycosylated proenzyme. Upon cleavage the 22-46 kDa5 MMP-1 becomes active in extracellular matrix remodeling.
Because of the prominent role that MMP-1 plays in cell migration and metastasis, it is an important target for inhibition screening.

Zinc-alpha-2-glycoprotein (ZAG) is found in body fluids such as serum, sweat, and seminal and breast cyst fluids. It is identical in amino acid sequence to tumor-derived lipid mobilizing factor (LMF), a protein associated with the dramatic loss of adipose body stores in cancer cachexia, and has been shown to stimulate lipolysis by adipocytes in vivo and in vitro. A role for ZAG has been proposed in the regulation of body weight, and age-dependent changes in genetically influenced obesity, and also it regulates melanin production by normal and malignant melanocytes. It has also recently been classified as a novel adipokine in that it is produced by both white and brown fat adipocytes and may act in a local autocrine fashion in the reduction of adiposity in cachexia. Controlling ZAG/LMF's activity could be life-saving in the management of certain cancers and other cachexiainducing conditions, and its possible normal role in body fat store homeostasis is deserving of understanding in its own right. ZAG exhibits a class I major histocompatibility complex (MHC) fold but is a soluble protein rather than being anchored to plasma membranes and does not associate with alpha-2-microglobulin in humans. Like antigen-presenting MHC class I proteins, ZAG has an open apical groove, and X-ray crystallography of human derived ZAG revealed an unidentifiable electron density in a similar position to that occupied by antigenic peptides in classical MHC proteins and glycolipids in isoforms of CD1. This presumptive ligand is not a peptide, and the groove is too small to hold a glycolipid such as is presented by CD1 isoforms. By analogy with all other MHC class I-related proteins that have an open apical groove [some do not ], occupancy by a ligand is probably crucial to ZAG's biological function. Despite all of the structural and biochemical evidence that ZAG binds a ligand, none has so far been found by extraction from protein isolated from biological fluids. This difficulty could be because the ligand is labile, heterogeneous, or readily lost during purification procedures. Knowing more about how ZAG interacts with the compounds it has been found to bind, both natural and artificial, will inform searches for the elusive ligand(s) and its/their role in ZAG's signaling function.

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).

Pleiotrophin (Osteoblast-Specific Factor-1, OSF-1) contains 136 amino acid residues. The sequence is very rich in cationic amino acids (24% of the residues); lysine cluster sequences are found in the N-terminal and C-terminal ends of the structure.
The OSF-1 gene was shown by Northern blotting analysis to be expressed in mouse calvarial osteoblast-enriched cells and in mouse brain tissues, but not in thymus, spleen, kidney, liver, lung, testis or heart. Pleiotrophin has the ability to promote adhesion, migration, expansion, and differentiation of human osteoprogenitor cells. In addition to certain types of cancer, the embryonic growth and differentiation factor pleiotrophin is found also in adults in inflammatory diseases. In osteoarthritis, pleiotrophin is especially expressed in early stages, and its concentrations in the synovial fluid could serve as a marker for the progress of the disease. Pleitrophin might be involved in cartilage repair in osteoarthritis, in particular, in earlier stages.