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Crystallins are the main structural proteins of the vertebrate eye lens, where they maintain the transparency and refractive index of the lens. Crystallins are divided into 3 fprotein families, α, β, & γ families. Because lens central fiber cells lose their nuclei during development, these crystallins are prepared and then retained throughout life, making them extremely stable proteins. CRYBB1 is a beta basic group member and undergoes extensive cleavage at its N-terminal extension during lens maturation.

FABP7 is a brain fatty acid binding protein. Fatty acid binding proteins (FABPs) are a family of small, highly conserved, cytoplasmic proteins that bind long-chain fatty acids and other hydrophobic ligands. FABPs are are inovlved in fatty acid uptake, transport, and metabolism. FABP7 is expressed in radial glia by the activation of Notch receptors and binds DHA with the highest affinity among all of FABPs. FABP7 plays an important role in transport of hydrophobic ligand with potential morphogenic activity during cns development. FABP7 is required for the establishment of the radial glial fiber system in developing brain, a system that is necessary for the migration of immature neurons to establish cortical layers (by similarity).

Mammalian crystallins which are water soluble structural proteins located in the vertebrate eye are classified in three forms, labeled alpha, beta and gamma. Crystallins, the primary components of the lens, raise the refractive index of the eye all through the accommodation by creating high-molecular weight aggregates that maintain transparency. CRYGS is a monomer that does not aggregate. CRYGS encodes the most substantial gamma-crystallin in adult eye lens tissue. Gamma-crystallins has a part in cataract formation due to aging or mutations in specific genes,

Cysteine-Rich Secretory Protein 2 (CRISP2) regulates some ion channels activity and thereby regulates calcium fluxes during sperm capacitation. Amongst its related pathways are p53 signaling. Diseases related with CRISP2 include epididymitis and orchitis.

SCGN is a secreted calcium-binding protein which is found in the cytoplasm. It is related to calbindin D-28K and calretinin. Secretagogin is involved in KCL-stimulated calcium flux and cell proliferation.
Secretagogin plays a role in human non-functional pituitary adenomas.

MAEA is a 396aa widely expressed adhesion protein which has 5 alternatively spliced isoforms. MAEA holds one CTLH domain and one LisH domain. MAEA forms a complex with F-actin, which takes part in regulating actin distribution in erythroblasts and macrophages and is known to assist in cell division and nuclear architecture. MAEA is confined with condensed chromatin at prophase, nuclear spindle poles at metaphase and in the contractile ring throughout cytokinesis phase and telophase.

SCG3 belongs to the chromogranin/secretogranin family of neuroendocrine secretory proteins. Though, the function of SCG3 is unknown, Granins operate as precursors for biologically active peptides. Several granins are known to serve as helper proteins in sorting and proteolytic processing of prohormones.

Growth/differentiation factors (GDF1-GDF15) belong to the BMP family of TGF-beta superfamily proteins. These factors are produced as inactive preproproteins which are subsequently cleaved and assembled into active secreted homodimers. BMP13 is a growth factor which controls proliferation and cellular differentiation in the retina and bone formation. BMP13 has a central role in regulating apoptosis during retinal development. GDF proteins are vital during embryonic development, particularly in the skeletal, nervous, and muscular systems. BMP13 gene mutations result in colobomata, which are congenital abnormalities in ocular development, and in Klippel-Feil syndrome (KFS), which is a congenital disorder of spinal segmentation.

FGFR1, also called fibroblast growth factor receptor 1 protein is encoded by the FGFR1 Gene. There are 4 types of related proteins (fibroblast growth factor receptors), one of them is the FGFR1 protein. The fibroblast growth factor receptors are responsible for many key cell pathways and processes, cell growth regulations, maturation processes, cell division, embryonic development, blood vessels formations etc.

Fibroblast Growth Factors (FGFs) comprise a family of at least eighteen structurally realted proteins that are involved in a multitude of physiological and pathological cellular processes, including cell growth, differentation, angiogenesis, wound healing and tumorgenesis. The biological activities of the FGFs are mediated by a family if type I transmembrane tyrosine kinases which undergo dimerization and autophosphorylation after ligand binding. Four distinct genes encoding closely related FGF receptors, FGFR-1to -4 are known. Multiple forms of FGFR-1 to -3 are generated by alternative splicing of the mRNAs. A frequent splicing event involving FGFR-1 and -2 results in receptors containing all three Ig domains, referred to as the alpha isoform, or only IgII and IgIII, referred to as the ? isoform. Only the alpha isoform has been identified for FGFR-3 and FGFR-4. Additional splicing events for FGFR-1 to -3, involving the C-terminal half of the IgIII domain encoded by two mutually exclusive alternative exons, generate FGF receptors with alternative IgIII domains (IIIb and IIIc). A IIIa isoform which is a secreted FGF binding protein containing only the N-terminal half of the IgIII domain plus some intron sequences has also been reported for FGFR-1. Mutations in FGFR-1 to -3 have been found in patients with birth defects involving craniosynostosis.

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%.

Ras-related GTP binding C (RRAGC) is a monomeric guanine nucleotide-binding protein, or G protein. As a result of binding GTP or GDP, small G proteins act as molecular regulators in various cell processes and signaling pathways. RRAGC regulates the organization of the actin cytoskeleton and has an intrinsic GTPase activity. RRAGC is possibly necessary for the amino acid-induced relocalization of mTORC1 to the lysosomes and its succeeding activation by the GTPase RHEB, which is key step in the activation of the TOR signaling cascade by amino acids.

TYRP1, also known as 5, 6-dihydroxyindole-2-carboxylic acid oxidase, is a melanosomal enzyme which is a member of the tyrosinase family and takes a significant part in the melanin biosynthetic pathway. TYRP1 is a melanocyte-specific gene which is involved in eumelanin synthesis. Furthermore, TYRP1 is implicated in the oxidation of 5,6-dihydroxyindole-2-carboxylic acid-DHICA into indole-5,6-quinone-2-carboxylic acid. TYRP1 is regulated by the microphthalmia-associatedtranscription factor-MITF.

Plasma fibronectin level is elevated in severe coronary artery disease. Increased plasma fibronectin levels are related with venous thromboembolism (VTE) particularly in males, and extend the probable association between biomarkers and risk factors for arterial atherothrombosis and VTE. Fibronectin plays a role in several cellular processes, including tissue repair, embryogenesis, blood clotting, and cell migration/adhesion. Fibronectin consists in two main forms: 1) as an insoluble glycoprotein dimer that serves as a linker in the extracellular matrix and 2) as a soluble disulphide linked dimer found in the plasma. The plasma form is produced by hepatocytes, and the ECM form is synthesized by fibroblasts, chondrocytes, endothelial cells, macrophages, as well as certain epithelial cells. Fibronectin also takes part as a general cell adhesion molecule by anchoring cells to collagen or proteoglycan substrates. Fibronectin organizes cellular interaction with the ECM by binding to different components of the extracellular matrix and to membrane-bound Fibronectin receptors on cell surfaces.

ZMAT3 is a protein with a nuclear localization signal and 3 zinc finger domains. The mRNA and the protein of this gene are upregulated by wildtype p53. When overexpressed, ZMAT3 can produce tumor cell growth, indicating that ZMAT3 takes part in the p53-dependent growth regulatory pathway. Alternative splicing of ZMAT3 produce two transcript variants encoding two isoforms differing in only one amino acid.

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.

Fibrinogen Beta Chain 9 (FGB) is the beta component of fibrinogen, a blood-borne glycoprotein composed of 3 pairs of nonidentical polypeptide chains. When vascular injury accrues, fibrinogen is cleaved by thrombin to form fibrin which is found in abundance in blood clots.

The mammaglobin gene was first identified using a differential screening approach directed at the isolation of novel, human breast cancer-associated genes. Mammaglobin encodes a 10 kDa glycoprotein and is distantly relaetd to a family of epithelial secretory proteins that includes rat estramustine-binding protein/prostatein and human Clara cell 10 kDa protein (CC10)/uteroglobin. Mammaglobin, a mammary-specific member of the uterglobin family, is known to be overexpressed in human breast cancer. Studies suggest that mammaglobin is one of the first relatively mammary-specific and mammary-sensitive markers (85%). Mammaglobin may be valuable used in a panel with BRST-2 (GCDFP-15) and ER in evaluating tumors of unknown primary sites.
SCGB2A2 (the mammaglobin gene) is located on chromosome 11, at locus 11q13. SCGB2A2 is member of the secretoglobin superfamily of which is a group of small dimeric secreted and sometimes glycosylated proteins. Expressed mainly in mucosa, secretoglobins appear to be involved in cell signalling, immune response, chemotaxis, and might also serve as transporters for steroid hormones in humans.

Fibronectin Leucine Rich Transmembrane Protein 3, also known as FLRT3 is a member of the fibronectin leucine rich transmembrane protein (FLRT) family. FLRT3 contains one fibronectin type-III domain as well as 10 LRR (leucine-rich) repeats and is expressed in the kidney, brain, pancreas, skeletal muscle, lung, liver, placenta, and heart. In addition, the members of the FLRT family play a role in cell adhesion as well as receptor signaling. FLRT3 has been implicated in neurite outgrowth after nerve damage, as a positive regulator of FGF signalling and in homotypic cell adhesion. Furthermore, FLRT3 has an essential function in regulating cellular adhesion among the epithelial apical ridge and the underlying mesenchyme and also in the establishment of the dorso-ventral position of the ridge.

RAB27B is a member of the RAB family and is an important regulator of vesicular transport. RAB27B is expressed in pituitary tissue, but is more extensively expressed in brain and spleen. RAB27B may be functionally redundant to Rab27a, as it can salvage Rab27a mutants.

Secretoglobin Family 1D, Member 1 (SCGB1D1) belongs to the lipophilin subfamily, part of the uteroglobin superfamily, and is an ortholog of prostatein (which is the major secretory glycoprotein of the rat ventral prostate gland). SCGB1D1 binds androgens and other steroids. In addition SCGB1D1 binds chemotherapeutic drugs during the prostate cancer treatment. Steroid hormones regulate the SCGB1D1 transcription. SCGB1D1 is secreted into extracellular space. SCGB1D1 gene product represents one component of a heterodimeric molecule found in human tears whose elution profile is consistent with prostatein (which is a tetrameric molecule comprised of 3 peptide components in heterodimers).

Obestatin is a hormone that is produced in the cells lining the stomach and small intestine of several mammals including humans; it drastically reduces appetite in mice and is expected to do the same in humans. Obestatin is a peptide hormone - a relatively small protein. It is encoded by the same gene that also encodes ghrelin, a peptide hormone that increases appetite. The protein produced by that gene breaks into two smaller peptides, ghrelin and obestatin. Ghrelin is an endogenous ligand for the growth hormone secretagogue receptor and is involved in regulating growth hormone release. Ghrelin is derived from a preprohormone called preproghrelin, which also generates a second peptide called obestatin. Ghrelin is an endogenous ligand for the orphan G protein-coupled receptor GPR39 and is involved in satiety and decreased food intake.

FKBP4 is part of the immunophilin protein family, which takes part in immunoregulation and necessary cellular processes concerning protein folding and trafficking. FKBP4 is a cis-trans prolyl isomerase that connects to the immunosuppressants FK506 and rapamycin. FKBP4 has high structural and functional similarity to FKBP1A, though, FKBP4 does not have immunosuppressant activity when complexed with FK506. FKBP4 is known to connect with phytanoyl-CoA alpha-hydroxylase. FKBP4 associates with HSP90 & HSP70 thus takes part in the intracellular trafficking of hetero-oligomeric forms of the steroid hormone receptors. FKBP4 highly associates with adeno-associated virus type 2 vectors (AAV) resulting in a considerable increase in AAV-mediated transgene expression in human cell lines. FKBP4 is involved in the optimal use of AAV vectors in human gene therapy.

SPARC, an acronym for “secreted protein, acidic and rich in cysteine”, is also known as osteonectin or BM-40. It is the founding member of a family of secreted matricellular proteins with similar domain structure. The 303 amino acid, 43 kDa protein contains a 17 aa signal sequence, an N-terminal acidic region that binds calcium, a follistatin domain containing Kazal-like sequences, and a C-terminal extracellular calcium (EC) binding domain with two EF-hand motifs. SPARC is produced by fibroblasts, capillary endothelial cells, platelets and macrophages, especially in areas of tissue morphogenesis and remodeling. SPARC shows context-specific effects, but generally inhibits adhesion, spreading and proliferation, and promotes collagen matrix formation. For endothelial cells, SPARC disrupts focal adhesions and binds and sequesters PDGF and VEGF. SPARC is abundantly expressed in bone, where it promotes osteoblast differentiation and inhibits adipogenesis.