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L-Selectin belongs to a family of divalent cation-dependent carbohydrate-binding glycoproteins or adhesion molecules. The L-Selectin molecule is composed of various domains: one homologous to lectins, one to epidermal growth factor, and two to the consensus repeat units found in C3/C4 binding proteins.
L-selectin is expressed constitutively on lymphocytes, monocytes and granulocytes and interacts specifically with carbohydrate groups on activated endothelial cells. L-Selectin may be shed by proteolytic cleavage and circulating levels in biological fluids may be used as an indicator of various pathological conditions. L-Selectin is cleaved by ADAM17.
L-selectin works as a "homing receptor" for leukocytes to enter secondary lymphoid tissues via the high endothelial venules. Ligands present on endothelial cells will attach to leukocytes expressing L-selectin, which causes the leukocytes to become localized at that juncture. The receptor is also located on the cell surfaces of "naive" T cells, which have not yet encountered their particular antigen. This surface expression is lost following the cells activation.

SELPLG glycoprotein functions as a high affinity counter-receptor for the cell adhesion selectin molecules (P, E and L) located in stimulated T lymphocytes and myeloid cells. SELPLG binds leukocytes to activated platelets or endothelia expressing selectins, a vital role in leukocyte trafficking throughout inflammation. In order to have a high-affinity binding activity SELPLG needs two post-translational modifications, tyrosine sulfation and the addition of the sialyl Lewis x tetrasaccharide (sLex) to its O-linked glycans. Polymorphisms and abnormal expression of SELPLG are linked to defects in the innate and adaptive immune response. Alternate splicing results in multiple transcript variants.

SCG5 also called 7B2 protein is localized in neuroendocrine tissues. SCG5 functions as a chaperone protein for the proprotein convertase PC2 and is essential for the production of an active PC2 enzyme.

S100A8 is a part of the S100 family of proteins containing 2 EF-hand calcium-binding motifs. S100 proteins are localized in the cytoplasm and/or nucleus of a broad range of cells, and participate in the regulation of cellular processes such as cell cycle progression and differentiation. S100A8 plays a role in the inhibition of casein kinase and as a cytokine. S100A8 altered expression is related with cystic fibrosis disease. S100A8 is a calcium-binding protein that has antimicrobial activity against bacteria and fungi.S100A8 is crucial for resistance towards invasion by pathogenic bacteria. S100A8 up-regulates transcription of genes that are under the control of NF-kappa-B. S100A8 plays a role in the development of endotoxic shock in response to bacterial lipopolysaccharide. S100A8 endorses tubulin polymerization and promotes phagocyte migration and infiltration of granulocytes at sites of wounding. S100A8 takes part as a pro-inflammatory mediator in acute and chronic inflammation and up-regulates the release of IL8 and cell-surface expression of ICAM1.

Polcalcin Aln g 4 (Aln G 4.0101) causes an allergic reaction in humans.

SRGN is identified as a hematopoietic cell granule proteoglycan. Proteoglycans stored in the secretory granules of various hematopoietic cells also hold a protease-resistant peptide core, and is vital for neutralizing hydrolytic enzymes. SRGN is related to the macromolecular complex of granzymes and perforin that acts as a intermediary of granule-mediated apoptosis.

EDN3 interacts with endothelin receptor B, on the surface of cells. Throughout embryonic development, EDN3 takes part in neural crest cells that migrate from the developing spinal cord to specific regions in the embryo, where they give rise to many different types of cells. EDN3 and EDN3R are necessary for the formation of nerves in the large intestine (enteric nerves) and melanocytes (produce melanin). Mutations in the EDN3 gene is linked with Waardenburg syndrome, type IV that is characterized by changes in skin, hair, and eye coloring. Mutations in the EDN3 gene is linked with Hirschsprung disease that causes severe constipation or intestinal blockage.

Vitronectin (VTN) which is a part of the pexin family is a cell adhesion and spreading factor found in serum and tissues. VTN interacts with glycosaminoglycans and proteoglycans. VTN inhibits the membrane-damaging effect of the terminal cytolytic complement pathway and binds to numerous serpin serine protease inhibitors. Scientists have been noticed an over expression of VTN, integrins and plasminogen in migrating cells during wound healing.

TARC cDNA encodes a 94 amino acid precursor protein with a 23 amino acid residue signal peptide that is cleaved off to generate the 71 amino acid residue mature secreted protein. Along with CC chemokine family members, CCL-17 has approximately 24-29% amino acid sequence identity with RANTES, MIP-1a, MIP-1b, MCP-1, MCP-2, MCP-3 and I-309. TARC is expressed in thymus, and at a lower level in the lung, colon, and small intestine. TARC is in addition transiently expressed in stimulated peripheral blood mononuclear cells. Recombinant TARC has been shown to be chemotactic for T cell lines but not monocytes or neutrophils. CCL-17 was recently identified to be a specific functional ligand for CCR4, a receptor that is selectively expressed on T cells. CCL17 is one of quite a few Cys-Cys (CC) cytokine genes clustered on the q arm of chromosome 16. CCL17 shows chemotactic activity for T lymphocytes, but not monocytes or granulocytes. CCL17 binds to chemokine receptors CCR4 and CCR8. This chemokine plays important roles in T cell development in thymus as well as in trafficking and activation of mature T cells.

SKP is a 17kDa trimeric periplasmic chaperone that supports outer membrane proteins in their folding and insertion into membranes. SKP protein is necessary for the normal release of ompA from the inner membrane, the maintenance of its solubility in the periplasm, and, in association with lipopolysaccharide (LPS), for the efficient folding and insertion of ompA into the outer membrane.

Native human C3 is a naturally glycosylated polypeptide containing two disulfide-linked chains. 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.

RANKL binds to tnfrsf11b/opg and to tnfrsf11a/rank. Osteoclast differentiation and activation factor. Augments the ability of dendritic cells to stimulate naive t-cell proliferation. May be an important regulator of interactions between t-cells and dendritic cells and may play a role in the regulation of the t-cell-dependent immune response. sRANKL may also play an important role in enhanced bone-resorption in humoral hypercalcemia of malignancy.

Native human C4 is aglycosylated polypeptide containing 3 disulfide-linked chains. C4 is essential to the activation of both thelectin and the classical pathways of complement activation.Initiation of each pathway generates proteolytic enzyme complexes which are bound to the target surface. These enzymes cleave a peptide bond in C4 releasing the anaphylatoxin C4a and activating C4b. Like C3, the thioester of metastable C4b is highly reactive and is capable of reacting and covalently coupling C4b to amino or hydroxyl groups on the target surface. C4A and C4B are 2 variants of C4 that are common in manwhereas, in animals who have only 1 type usually have C4B.

C1QTNF3 also called Cartducin is a novel angiogenic factor in the formation of neointima following angioplasty. C1QTNF3 a paralog of Acrp30 (adiponectin). C1QTNF3 is a secretory protein produced by chondrogenic precursors & proliferating chondrocytes, and belongs to a novel C1q family of proteins. Cartducin promotes the growth of mesenchymal chondroprogenitor cells & chondrosarcoma-derived chondrocytic cells in vitro. Cartducin stimulates mesenchymal chondroprogenitor cell proliferation through extracellular signal-regulated kinase and phosphatidylinositol 3-kinase/Akt pathways. C1QTNF3 promotes proliferation & the migration of endothelial cells.

Matrix metalloproteinase-2 (MMP-2) is involved in endometrial menstrual breakdown, regulation of vascularization and the inflammatory response. MMP-2 contains a number of distinct domains: a prodomain that is cleaved upon activation; a catalytic domain containing the zinc binding site; a fibronectin like domain believed to have a role in substrate targeting; and a carboxyl terminal (hemopexin like) domain containing 2 N-linked glycosylation. The MMP-2 can degrade an extensive array of substrates including type IV, V, VII and X collagens as well as gelatin type I. In addition, MMP-2 interacts with THBS2, TIMP2, Thrombospondin 1, CCL7 and TIMP4. MMP-2 autocatalytic cleavage in the C-terminal generates the anti-angiogenic peptide, PEX. This process seems to be made possible by binding integrinv/beta3. Defects in the MMP-2 are the cause of Torg-Winchester syndrome (TWS), aka multicentric osteolysis nodulosis and arthropathy (MONA).

Fractalkine soluble form is chemotactic for t-cells and monocytes, but not for neutrophils. Fractalkine membrane-bound form promotes adhesion of those leukocytes to endothelial cells. Fractalkine regulates leukocyte adhesion and migration processes at the endothelium and binds to CX3CR1. Fractalkine gene is located on human chromosome 16 along with some CC chemokines known as CCL17 and CCL22.

CRNN is part of the "fused gene" family of proteins, which enclose N-terminus EF-hand domains and multiple tandem peptide repeats. CRNN contains two EF-hand Ca2+ binding domains in its N-terminus and two glutamine- and threonine-rich 60 amino acid repeats in its C-terminus. CRNN, also known as SEP53, which participates in the mucosal/epithelial immune response and epidermal differentiation. CRNN is a survival factor that participates in the clonogenicity of squamous esophageal epithelium cell lines, attenuates deoxycholic acid (DCA)-induced apoptotic cell death and discharge of calcium. When CRNN is over expressed in oral squamous carcinoma cell lines, it regulates negatively cell proliferation by the induction of G1 arrest.

Integrins are heterodimeric proteins consist of alpha and beta subunits. There are more than 18 alpha and 8 beta subunits discovered in mammals. Integrin family members are membrane receptors that participates in cell adhesion and recognition in a variety of processes including embryogenesis, hemostasis, tissue repair, immune response and metastatic diffusion of tumor cells. ITGB1 encodes a beta subunit.

CCL3L1 is a small cytokine that belongs to the CC chemokines. The CCL3L1 gene is one of several cytokine genes clustered on the q-arm of chromosome 17. CCL3L1 is involved in immunoregulatory and inflammatory processes. CCL3L1 binds to several chemokine receptors including CCBP2 and CCR5. CCR5 is a co-receptor for HIV, and binding of the CCL3L1 protein to CCR5 inhibits HIV entry.

The secreted polypeptide noggin, encoded by the NOG gene, binds and inactivates members of the transforming growth factor-beta (TGF-beta) superfamily signaling proteins, such as bone morphogenetic protein-4 (BMP4). By diffusing through extracellular matrices more efficiently than members of the TGF-beta superfamily, noggin may have a principal role in creating morphogenic gradients. Noggin appears to have pleiotropic effect, both early in development as well as in later stages. It was originally isolated from Xenopus based on its ability to restore normal dorsal-ventral body axis in embryos that had been artificially ventralized by UV treatment. The results of the mouse knockout of noggin suggest that it is involved in numerous developmental processes, such as neural tube fusion and joint formation. Recently, several dominant human NOG mutations in unrelated families with proximal symphalangism (SYM1) and multiple synostoses syndrome (SYNS1) were identified; both SYM1 and SYNS1 have multiple joint fusion as their principal feature, and map to the same region (17q22) as NOG. All NOG mutations altered evolutionarily conserved amino acid residues. The amino acid sequence of human noggin is highly homologous to that of Xenopus, rat and mouse.

MMP-1 (interstitial collagenase) can break down a wide range of substrates including types I, II, III, VII, VIII, and X collagens as well as L-Selectin, pro-TNF, IGFBP-3, IGFBP-5, casein, gelatin, myelin basic protein, pro-MMP2 and pro-MMP9. A significant function of MMP-1 is the degradation of fibrillar collagens in extracellular matrix remodeling. MMP-1 is expressed in fibroblasts, keratinocytes, endothelial cells, monocytes and macrophages. MMP1 can be divided into a number of distinct domains: a prodomain which is cleaved on activation, a catalytic domain containing the zinc binding site and a short hinge region with a carboxyl terminal domain. MMP1 is part of a cluster of MMP genes which localize to chromosome 11q22.3.

MGP is vital for the regulation of calcification in the extracellular matrix, particularly in cartilage and arteries. The K-dependent vitamin MGP has five to six residues of Gla, a Ca2+ binding amino acid crucial for vitamin K-dependent gamma carboxylase for its formation. MGP is formed by COOH-terminal processing by carboxypeptidase B-like enzymatic activity and localized in the human bone.

ACTN1 encodes a nonmuscle, cytoskeletal, alpha actinin isoform and maps to the same site as the structurally similar erythroid beta spectrin gene. Alpha actinins belong to the spectrin gene superfamily which represents a diverse group of cytoskeletal proteins, including the alpha and beta spectrins and dystrophins. Alpha actinin is an actin-binding protein with multiple roles in different cell types. In nonmuscle cells, the cytoskeletal isoform is found along microfilament bundles and adherens-type junctions, where it is involved in binding actin to the membrane. In contrast, skeletal, cardiac, and smooth muscle isoforms are localized to the Z-disc and analogous dense bodies, where they help anchor the myofibrillar actin filaments.

UCHL1 (PGP9.5) belongs to a gene family whose products hydrolyze small C-terminal adducts of ubiquitin to produce the ubiquitin monomer. Protein Gene Product (PGP9.5) is a neuron specific protein, structurally and immunologically distinct from neuron specific enolase. Human UCHL1 and UCHL3 have an extremely complicated knot structure for a protein, with five knot crossings. It is considered that the knot structure may increase a protein's resistance to degradation in the proteasome.
The protein, which has a molecular weight of 27 kDa was first defined by high resolution two dimetional PAGE. Standard immunohistochemical techniques have demonstrated the presence of PGP9.5 in neurons and nerve fibers at all levels of the central and peripheral nervous system, in many neurodcrine cells, in segments of the renal tubules, in spermatogonia and leydig cells of the testis, in ova and in some cells of both the pregnant and non pregnant corpus luteum. A point mutation (I93M) in UCHL1 is implicated as the cause of Parkinson's disease in one kindred. On the other hand, a polymorphism (S18Y) in UCHL1 has been found to be associated with a reduced risk for Parkinson's disease. Furthermore, UCHL1 is associated with the Alzheimer's disease, and required for normal synaptic and cognitive function.