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Apoptosis-Inducing Factor, Mitochondrion-Associated, 1 (AIFM1) is a mitochondrial protein which translocates to the nucleus once apoptosis has been initiated. AIFM1 causes DNA fragmentation and chromatin condensation and also triggers the release of cytochrome c and caspase-9 from mitochondria. Bcl-2 overexpression prevents the release of AIFM1 from mitochondria, but doesn’t block its apoptogenic activity.

Transcription Factor 4 (TCF4) acts as a transcription factor and takes part in the initiation of neuronal differentiation. TCF4 recognizes an Ephrussi-box ('E-box') binding site ('CANNTG') - a motif primary identified in immunoglobulin enhancers. TCF4 is mainly expressed in pre-B-cells, even though it is present in other tissues as well.

Insulin-like growth factor-binding protein 4 (IGFBP-4) is a part of the insulin-like growth factor binding protein (IGFBP) family. IGFBP4 includes an IGFBP domain and a thyroglobulin type-I domain. IGFBP4 binds both insulin-like growth factors (IGFs) I and II. IGFBP-4 circulates in the plasma in both glycosylated and non-glycosylated forms. IGFBPs can either inhibit or enhance the biological activities of IGF, or act in an IGF independent manner. IGFBP-4 is consistently inhibits several cancer cells in vivo and in vitro, suggesting that it may function as an apoptotic factor. IGFBP4 is produced by all colon cancer cells. Binding of IGFBP-4 prolongs the half-life of the IGFs and changes their interaction with cell surface receptors.

Vacuolar protein sorting-associated protein 26A (VPS26A) is a vital element of the retromer complex, which is required to recover lysosomal enzyme receptors (IGF2R and M6PR) from endosomes to the trans-Golgi network. Furthermore, VPS26A is essential in the regulation of transcytosis of the polymeric immunoglobulin receptor (pIgR-pIgA). Expression analysis in yeast and mammalian cells reveal that VPS26A interacts directly with VPS35 that functions as the core of the retromer complex.

Complement factor H (CFH) is an important regulatory component of the alternative pathway of complement. CFH is prevents complement activation on host cells and tissues, mainly the kidney. CFH controls the formation and decay of the alternative pathway C3/C5 convertase and acts as a cofactor for factor I which proteolytically inactivates C3b when C3b is bound to factor H. The N-terminal 5 domains of CFH bind to C3b and inhibit binding of factor B thus reducing the formation of C3/C5 convertase. CFH also binds to preformed C3/C5 convertases and causes quick release of the catalytic subunit Bb. These activities are necessary for controlling the spontaneous activation of the alternative pathway amplification process in plasma. In addition, CFH controls the formation and decay of these enzymes when C3b is attached to the surface of particles.

APOA1 (Apolipoprotein A-1) is a human protein with a specific role in lipid metabolism being the main protein component of HDL in the plasma. APOA1 promotes cholesterol efflux from tissues to the liver for excretion. Furthermore, APOA1 is a cofactor for LCAT, which is responsible for the formation of most plasma cholesteryl esters. In addition, APOA1 activates spermatozoa motility as part of the SPAP complex. The APOA1 gene is strongly linked with two other apolipoprotein genes on chromosome 11. Defects in the APOA1 gene are linked to HDL deficiency including Tangier disease, and with systemic non-neuropathic amyloidosis. High levels of APOA1 are linked to the manifestation of asthma and atopy.

EFNB1 is a member of the Eph family. The cell-surface proteins Ephrins split into two groups, ephrin-A and ephrin-B, based on their structure and function and perform as ligands for Eph receptors. The transmembrane EFNB1 proteins have conserved cytoplasmic tyrosine residues that are phosphorylated upon interaction with an EphB receptor. In addition, EFNB1 transduces outside-in signals by C-terminal protein interfaces which influence integrin-mediated cell attachment and migration.

Leptin takes an important part in the regulation of energy balance and body weight control.After entering the circulation, Leptin binds LEPRwhich results in the activation of several major signalling pathways. In the hypothalamus Leptin acts as an appetite-regulating factor that induces a decrease in food intake and an increase in energy consumption and also regulates bone mass and secretion of hypothalamo-pituitary-adrenal hormones. In the periphery, increases basal metabolism, regulates pancreatic beta-cell function and insulin secretion and affects innate and adaptive immunity.

Signal recognition particle 19kDa protein (SRP19) is a member of the SRP19 family. SRP19 binds directly to 7S RNA and mediates binding of the 54 kDa subunit of the SRP.

VPS28 is a subunit of the ESCRT-I complex (endosomal complexes required for transport) involved in the sorting of ubiquitinated proteins. VPS28 is involved in endosomal sorting of cell surface receptors using a multivesicular body/late endosome pathway. VSP28 binding with the TSG101 may have significant roles in budding of Retroviruses, such as HIV-1 and Ebola virus.
VSP28 interacts with TSG101, VPS37B, VPS37C, FAM125A and FAM125B, and also with VPS36, this interaction mediates the association with the ESCRT-II complex. Furthermore it interacts with SNF8 and VPS25 and CEP55.

Platelet factor-4 is a 70-amino acid protein that is released from the alpha-granules of activated platelets. Its major physiologic role appears to be neutralization of molecules on the endothelial surface of blood vessels, thereby inhibiting local 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 chemocinfamily.

The protein kinase A holoenzyme is a heterotetramer composed of two types of subunits: Catalytic and Regulatory. The Catalyticsubunit contains the enzyme's active site. It also contains a domain that binds ATP and a domain that binds the regulatory subunit. The Regulatory subunit consists oftwo molecules which bind one another in an anti-parallel orientation to form a homodimer; for type I subunits- this binding is covalent via disulfide bonds. This subunit also has has two domains that bind cyclic AMP, a domain that interacts with a catalytic subunit, and an "auto-inhibitory" domain that serves as a substrate or pseudosubstrate for the catalytic subunit. Regulatory subunits may also have biologic activity distinct from their role in modulating catalytic subunit activity. Regulatory subunits exist in two major forms, RI and RII, with each form having two subtypes designated alpha and beta. Each of the four isotypes of the regulatory subunit is encoded by a different gene. In addition, three isotypes of the catalytic subunit have been identified (alpha, beta and gamma). The different isotypes tend to have different distributions within cells and among tissues. Type I enzymes inhabit cytoplasmic, soluble fractions of the cell, whereas type II enzymes tend to associate with cellular membranes.

KLRB1 has an inhibitory role on natural killer (NK) cells cytotoxicity which are lymphocytes who facilitate cytotoxicity and secrete cytokines subsequent to immune stimulation. Some genes of the C-type lectin superfamily, like the rodent NKRP1 family of glycoproteins, are expressed by NK cells and take part in NK cell function regulation. KLRB1 holds an extracellular domain with a few characteristic motifs of C-type lectins, a transmembrane domain, and a cytoplasmic domain. Due to its external C terminus KLRB1 is considered to be a type II membrane protein.

GTPase, IMAP Family Member 5 (GIMAP5) is a part of the GTP-binding superfamily and the immuno-associated nucleotide subfamily of nucleotide-binding proteins. GIMAP5 is an antiapoptotic protein which is required for mitochondrial integrity and T-cell survival. Polymorphisms in GIMAP5 are related with systemic lupus erythematosus. Read-through transcription can be found between GIMAP5 and the neighboring upstream GIMAP1 (GTPase, IMAP family member 1) gene. GIMAP5 also contributes to T-cell quiescence.

Fructose-1,6-bisphosphatase isozyme 2 (FBP2) is a part of the FBPase class 1 family. FBP2 is a gluconeogenesis regulatory enzyme Which catalyzes the hydrolysis of fructose 1,6-bisphosphate to fructose 6-phosphate and inorganic phosphate.

Serpin Peptidase Inhibitor, Clade C Member 1 (SERPINC1), which is a part of the serpin superfamily, is a plasma protease inhibitor. SERPINC1 inhibits thrombin and other activated serine proteases of the coagulation system, and regulates the blood coagulation cascade. SERPINC1 also inhibits Thrombin and Factors IXa, Xa and XIa. Deficiencies in SERPINC1 can cause ATIII deficiency, an autosomal dominant disease which might lead to a hereditary thrombophilia.

Mature T-Cell Proliferation 1, also known as MTCP1 was recognized by involvement in some t(X;14) translocations linked with mature T-cellproliferations. This region has a complex gene structure, with a common promoter and 5' exon spliced to two dissimilar sets of 3' exons which encode two different proteins. It represents the upstream 13 kDa protein which belongs to the TCL1 family. In addition, MTCP1 enhances the phosphorylation and activation of AKT1 and AKT2. MTCP1 is involved in leukemogenesis.Among the diseases associated with MTCP1 are queensland tick typhus, and african tick-bite fever.

A 16-kDa peptide hormone secreted from white adipocytes and implicated in the regulation of food intake and energy balance. Leptin provides the key afferent signal from fat cells in the feedback system that controls body fat stores.

Phl p 7.0101 is a secondary allergen of timothy grass pollen, which is non-glycosylated protein. Grass pollen-sensitized individuals show IgE antibodies in their blood system. Phl p 7.0101 is a calcium binding protein with similar sequence to pollen antigens that exist in different plants, hence, cross-reactions are possible.

CAPG is part of the gelsolin/villin family of actin-regulatory proteins. CAPG reversibly blocks the barbed ends of F-actin filaments in a Ca2+ and phosphoinositide-regulated method, though it does not separate preformed actin filaments. By capping the barbed ends of actin filaments, CAPG contributes to the control of actin-based motility in non-muscle cells. CAPG is involved in macrophage function. CAPG is involved in regulating cytoplasmic and/or nuclear structures via possible interactions with actin. CAPG binds DNA. CAPG lacks a nuclear export sequence present in structurally related proteins. CAPG is a tumor suppressor protein that plays a role in the tumorigenic progression of certain cancers. Dysregulated expression of CAPG was found in premalignant and malignant oral carcinogenesis.

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.

Transcription elongation factor A protein-like 8 (TCEAL8) is a member of the TFS-II family and TFA subfamily. TCEAL8 is involved in transcriptional regulation and localized in nucleus. TFS-II family members contain TFA domains and act as nuclear phosphoproteins which control transcription in a promoter context-dependent mode. Numerous family members are found on the X chromosome.

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.

C1q is the first component of the classical pathway of complement activation. C1q along with the enzymatically active components C1r and C1s forms the C1 complex. When C1 binds to immunoglobulins in the form of immune complexes, it leads to activation of C1r and C1s proteases and a further activates the classical pathway of complement. C1q is a glycoprotein that belongs to the collectin family, having a molecular weight of about 410-462 kDa. C1q is a hexamer composed of globular heads attached to collagen-like triple-helix tails. The globular heads of C1q exclusively bind to the CH2 domain of IgG molecules or the CH3 domain of IgM. Each heavy chain of the immunoglobulin molecule contains a single binding site for C1q. Given that C1q must bind to no less than two heavy chains in order to alter its conformation and activate C1r and C1s, its activation follows only after binding to immunoglobulins in the form of immune complexes bound to multivalent antigens. C1q’s main physiological role is in the clearance of immune complexes and apoptotic bodies from the organism. Interruption of this process may lead to development of autoimmunity. Individuals with genetic deficiencies of C1q or other components of the classical pathway are at risk to develop SLE. C1q specifically binds to apoptotic bodies of human keratinocytes, vascular endothelial cells and lymphocytes. Complement components C1q and bound C3 mediate the clearance of apoptotic bodies. Hence, C1q may advance the clearance of autoantigens, avoiding stimulation of the immune system. Nonetheless, an extended exposition of the immune system to the neoepitope exposed on C1q molecules bound to immune complexes or apoptotic bodies could ultimately lead to an autoimmune response against C1q itself and to an altered complement function. C1q deficiency may also lead to disruption of the negative selection of autoreactive B cells. C1q along with other specific recognition proteins bind to the highly conserved lupus antigens (dsDNA and nuclear proteins) and activate the complement system. Autoantibodies against C1q (anti-C1q) are found in a number of autoimmune and infectious diseases like glomerulonephritis (GN) and lupus erythematosus (SLE), these antibodies are significant in clinical practice due to their negative predictive value.