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Protein Kinase CAMP-Dependent Catalytic Beta (PRKACB) belongs to the Ser/Thr protein kinase family and is a catalytic subunit of cAMP-dependent protein kinase. cAMP is a signaling molecule imperative for various cellular functions. cAMP activates the cAMP-dependent protein kinase, which transduces the signal by way of phosphorylation of different target proteins. The inactive kinase holoenzyme is a tetramer composed of 2 regulatory and 2 catalytic subunits. cAMP triggers the dissociation of the inactive holoenzyme into a dimer of regulatory subunits bound to 4 cAMP and 2 free monomeric catalytic subunits. PRKACB mediates cAMP-dependent signaling initiated by receptor binding to GPCRs. PKA activation regulates various cellular processes such as cell proliferation, the cell cycle, differentiation and regulation of microtubule dynamics, chromatin condensation and decondensation, nuclear envelope disassembly and reassembly, in addition to regulation of intracellular transport mechanisms and ion flux. PRKACB regulates the abundance of compartmentalized pools of its regulatory subunits via phosphorylation of PJA2 which binds and ubiquitinates these subunits, leading to their consequent proteolysis.

Tribbles Pseudokinase 3, also known as TRIB3, is a putative protein kinase which is induced by the transcription factor NF-kappaB. In addition, TRIB3 is a negative regulator of NF-kappaB, and can as well sensitize cells to TNF- and TRAIL-induced apoptosis. Furthermore, TRIB3 is able to negatively regulate the cell survival serine-threonine kinase AKT1. One of the diseases which are associated with TRIB3 is anoxia.

NAPA is part of the SNAP (Soluble NSF Attachment Protein) family. SNAPs, acting together with SNAREs (SNAP receptors) and the N-ethylmaleimide-sensitive fusion protein (NSF), are necessary for the fusion of transport vesicles to their objective membranes in synaptic transmission, intra-Golgi transport, endosome-to-endosome fusion and transcytotic vesicles-to-plasma membrane transport. NAPA is in charge of the binding of NSF and therefore the formation of a 20S fusion particle.

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.

Complement C5 is cleaved into C5a and C5b and is activated by all 3 pathways of complement activation. Each pathway of complement activation generates proteolytic enzyme complexes which binds to the target surface. These enzymes cleave a peptide bond in the larger alpha chain of C5 releasing the highly potent anaphylatoxin C5a and activating C5b. C5a has an imperative role in chemotaxis and C5b forms the 1st part of the complement membrane attack complex. Complement C5 is the 5th component of complement, which plays a central role in inflammatory and cell killing processes.

SecB, a significant chaperone that takes part in protein export, binds various ligands rapidly with high affinity and low specificity. SecB plays an important role during protein export through the general secretory pathway by modulating the partitioning of precursors between folding or aggregation and delivery to the membrane-bound translocation apparatus. SecB has the potential to take part in functions outside of export acting as a universal nonspecific chaperone to provide buffering capacity of the nonnative state of proteins in the cytosolic pool.

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.

Carcinoembryonic Antigen-Related Cell Adhesion Molecule 1 (CEACAM1) belongs to the carcinoembryonic antigen (CEA) gene family which is a part of the immunoglobulin superfamily. CEACAM1 is a cell adhesion protein which mediates homophilic cell adhesion in a calcium-independent way. CEACAM1 is a surface glycoprotein expressed on various blood cells, epithelial cells, and vascular cells. CEACAM1 functions as coinhibitory receptor in immune response, and plays a role also as an activator during angiogenesis.

LGALS8 is a prostate-specific antigen that is solely overexpressed in malignant tumors and thus is a supplementary specific identifier of malignancies. LGALS8 is part of the galectin gene family which facilitates both cell-cell and cell matrix interactions in a method parallel to the selectin subgroup of C-type lectins.

PEBP1 (Phosphatidylethanolamine binding protein 1) belongs to the phosphatidylethanolamine-binding protein family and a serine protease inhibitor that inhibits thrombin, neuropsin. PEBP1 plays a key modulatory part in several protein kinase signaling cascades. PKC phosphorylates PEBP1, resulting in the release of Raf-1 and activation of MEK and ERK. PEBP1 is expressed in many tissues and implicated in the regulation of such physiological processes as membrane biosynthesis, spermatogenesis, neural development, and metastasis suppression.
PEBP1 binds ATP, opioids and phosphatidylethanolamine, however it has lower affinity for phosphatidylinositol and phosphatidylcholine. PEBP1 may also be involved in the function of the presynaptic cholinergic neurons of the CNS. PEBP1 increases the production of choline acetyltransferase although not acetylcholinesterase. Furtheremore, PEBP1 functions in potentially sequestering toxic compounds, including locostatin which may have harmful effects on cells.
Loss of PEBP1 expression may have a significant role as prognostic marker in Gastrointestinal stromal tumors. In addition, PEBP1 is found differentially expressed in the Wernicke's Area from schizophrenia patients. PEBP1 is also, an invasion suppressor protein in nasopharyngeal carcinoma.

UCN119B is a member of the PDE6D/unc-119 family. UCN119B has a large number of photoreceptors of the retina. Additionaly, UCN119B has a strong homology with the C. elegans unc119 and is able to functionally complement the C. elegans unc119 mutation gene.

Bone Morphogenetic protein-8b (BMP8B) belongs to a family of secreted signaling molecules which can induce ectopic bone growth. BMP8B is known for having a possible bone inductive activity as it is related to BMP5 and BMP7. BMP8B is the osteoinductive factor accountable for epithelial osteogenesis.

MYC Induced Nuclear Antigen, also known as MINA is an oxygenase which can function both as a histone lysine demethylase and a ribosomal histidine hydroxylase. MINA is involved in the demethylation of trimethylated Lys-9 on histone H3 (H3K9me3), leading to an increase in ribosomal RNA expression. MINA also catalyzes the hydroxylation of 60S ribosomal protein L27a on His-39. In addition, MINA plays a significant role in cell growth and survival. MINA is implicated in ribosome biogenesis, probably in the duration of the assembly process of pre-ribosomal particles.

Ring Finger & CHY Zinc Finger Domain Containing 1 (RCHY1) acts as an ubiquitin ligase. RCHY1 mediates E3-dependent ubiquitination and proteasomal degradation of target proteins which among them are TP53, HDAC1 and CDKN1B, consequently regulating their levels and cell cycle progression. RCHY1 is also increases AR transcription factor activity.

Calretinin is an intracellular calcium-binding protein belonging to the troponin C superfamily characterized by a structural motif described as the EF-hand domain. The immunohistochemical detection of calretinin in developing cerebellum is restricted to the later stages indicated by weak staining from week 21 of gestation, in Purkinje and basket cells and in neurons of the dentate nucleus. The intensity of staining increases as the cerebellum matures. In tumors, calretinin has been detected in mesotheliomas and some pulmonary adenocarcinomas.

Leptin Receptor is a part of the gp130 family of cytokine receptors that stimulate gene transcription by activating cytosolic STAT proteins. Leptin Receptor plays a role in the regulation of fat metabolism and in novel hematopoietic pathway that is obligatory for normal lymphopoiesis. Leptin Receptorparticipates in the regulation of counter-regulatory response to hypoglycemia by inhibiting neurons of the parabrachial nucleus.Leptin Receptoraffectsspecifically on T lymphocyte responses.

MRG-binding protein (MRGBP or C20ORF20) is a 204 amino acid protein which is a part of the NuA4 histone acetyltransferase (HAT) complex that functions to acetylate histone H2A and H4. The HAT complex may be essential for the activation of transcriptional programs linked with oncogene and proto-oncogene mediated growth induction, tumor suppressor mediated growth arrest and replicative senescence, apoptosis, and DNA repair. C20ORF20 also has a potential to interact with MORF4L1/MRG15 and MORF4L2/MRGX.

The PARK7 is a ubiquitously expressed protein involved in various cellular processes including spermatogenesis and fertilization, cancer, RNA-binding, androgen-receptor signaling and oxidative stress. Mutations in the PARK7 are the cause of autosomal recessive early-onset Parkinson’s disease 7 (Park7).

GTP Cyclohydrolase I Feedback Regulator, also known as GCHFR, is a Protein coding gene which includes a homodimer. GCHFR binds and mediates tetrahydrobiopterin inhibition of GTP cyclohydrolase I. GCHFR also regulates phenylalanine metabolism in the liver and in the production of biogenic amine neurotransmitters and nitric oxide.

VCAM1 is a member of the Ig superfamily. It is a cell surface sialoglycoprotein expressed by cytokine activated endothelium. VCAM-1 contains 6 or 7 immunoglobulin domains, and is expressed on both large and small vessels only after the endothelial cells are stimulated by cytokines. The protein has a number of functions including the regulation of leukocyte migration, leukocyte endothelial cell adhesion and signal transduction and may play a role in a number of inflammatory diseases (artherosclerosis and rheumatoid arthritis).

SIL1 is localized to endoplasmic reticulum (ER). SIL1 is an N-linked glycoprotein with an N-terminal ER targeting sequence, 2 putative N-glycosylation sites, and a C-terminal ER retention signal. SIL1 acts as a nucleotide exchange factor for another unfolded protein response protein. Mutations in SIL1 are linked to Marinesco-Sjogren syndrome.

Trafficking protein particle complex 4 (TRAPPC4) is part of the multisubunit TRAPP (transport protein particle) complex and interacts with SDC2. TRAPPC4 has a role in vesicular transport from endoplasmic reticulum to Golgi.

Adipogenesis Associated, Mth938 Domain Containing, also known as AAMDC is a member of the AAMDC family and takes part in preadipocyte differentiation andadipogenesis.

Cystatin 7 (CST7) is a glycosylated cysteine protease inhibitor with a putative role in immune regulation through inhibition of a unique target in the hematopoietic system. Cystatin-7 is comprised of multiple cystatin-like sequences. The superfamily is comprised of 3 inhibitory families: the type 1 cystatins (stefins), type 2 cystatins and the kininogens. Some members are active cysteine protease inhibitors, while others have lost or possibly never had this inhibitory activity. Type 2 cystatin proteins are a class of cysteine proteinase inhibitors found in various human fluids and secretions. CST7 protein expression has been observed in numerous human cancer cell lines established from malignant tumors.