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PSME1 is an interferon gamma (IFNG) inducible proteasome activator essential for presentation of certain major histocompatibility (MHC) class I antigens. The PSME1 complex is an alternate proteasome activator which operates with no use of ubiquitin. The PSME1 complex is made out of two homologous subunits, alpha and beta, that functions in similar catalytic properties and is connected to a hexameric ring.

Von Hippel-Lindau disease is a dominant inherited syndrome characterized by the predisposition to develop various kinds of benign and malignant tumors, including clear cell renal carcinomas, pheochromocytomas and hemangioblastomas of the central nervous system and retina. VHL syndrome is caused by germline mutation in the VHL tumor suppressor, and VHL tumors are associated with loss or mutation of the remaining wild-type allele. VHL has two domains: a roughly 100-residue NH2-terminal domain rich in  sheet (-domain) and a smaller -helical domain (-domain), held together by two linkers and a polar interface. VHL protein is also involved in the degradation of hypoxia-inducible factor (HIF).

Neisseria gonorrhoeae, also known as Gonococci is a Gram-negativebacteriahighly fastidiouscocci, requiring nutrient supplementation to survive. The cocci are facultatively intracellular and typically appear in pairs (diplococci).
Neisserial LPS is distinguished from enteric LPS by its highly-branched basal oligosaccharide structure and the absence of repeating O-antigen subunits. For these reasons, neisserial LPS is referred to as lipooligosaccharide (LOS). The bacterium characteristically releases outer membrane fragments called "blebs" during growth. These blebs contain LOS and probably have a role in pathogenesis if they are disseminated during the course of an infection.
Neisseria gonorrhoeae is a relatively fragile organism, susceptible to temperature changes, drying, uv light, and other environmental conditions. Strains of N. gonorrhoeae are variable in their cultural requirements so that media containing hemoglobin, NAD, yeast extract and other supplements are needed for isolation and growth of the organism.

Cystatin-A is the intracellular inhibitor of cysteine proteinase cathepsin B (CatB) and belongs to family 1 of the cystatin superfamily of inhibitor proteins. CSTA is a stefin that functions as a cysteine protease inhibitor, forming tight complexes with papain and the cathepsins B, H, and L. It has been proposed that extracellular CatB together with other classes of proteinases are all subjected to a cascade-like manner of activation. CatB and its inhibitor Cystatin-A are involved in degradation of extracellular matrix proteins during tissue remodeling. CSTA is one of the precursor proteins of cornified cell envelope in keratinocytes and plays a role in epidermal development and maintenance. Cystatin-A has been reported to be found in high concentrations in epithelial cells, polymorphonuclear leukocytes and lymphoid tissue. Stefins may be used as prognostic and diagnostic tools for cancer.

KLF4 (aka the gut-enriched Kruppel-like factor-GKLF), is a zinc finger-containing transcription factor which is a member of the Kruppel-like family of transcription factors. KLF4 plays key roles during the proliferation and differentiation of epithelial cells. Particularly, it is found mainly in the gut and has been shown to be expressed during growth arrest. KLF4 is also involved in cell cycle control since expression of KLF4 inhibits DNA synthesis by blocking the G1/S phase of the cell cycle.

Troponin I, (TNNI1) is a member of the troponin I family. Troponin complex has 3 subunits, TNNI1 known as the inhibitory Subunit which prevents the actin-myosin interactions and thus mediating striated muscle relaxation. TNNI1 combines with tropomyosin and regulates calcium sensitivity of striated muscles by structural modifications in actin-myosin complexes.

CD14 (also known lipopolysaccharide (LPS) receptor) is expressed strongly on monocytes and macrophage and weakly on the surface of neutrophils. CD14 is anchored to cells by linkage to glycosylphosphatidylinositol (GPI) and functions as a high affinity receptor for complexes of LPS and LPS binding protein (LBP). Soluble CD14, also binding to LPS, acts at physiological concentration as an LPS agonist and has, at higher concentrations, an LPS antagonizing effect in cell activation. CD14 has been shown to bind apoptotic cells.

CTK-19 is a member of the keratin family. The keratins are intermediate filament proteins responsible for the structural integrity of epithelial cells and are subdivided into cytokeratins and hair keratins. The type I cytokeratins consist of acidic proteins which are arranged in pairs of heterotypic keratin chains. Unlike its related family members, this smallest known acidic cytokeratin is not paired with a basic cytokeratin in epithelial cells. It is specifically expressed in the periderm, the transiently superficial layer that envelopes the developing epidermis. The type I cytokeratins are clustered in a region of chromosome 17q12-q21.

The T1/Leu1/CD5 molecule, a human T-cell surface glycoprotein of relative molecular mass (Mr) 67,000, has been implicated in the proliferative response of activated T cells and in T-cell helper function. Ly1 is the murine homolog. (In the mouse, lymphocyte surface antigens that are markers for function have been identified. Allelic forms are known and chromosomal assignment of the loci has been achieved. Ly1 is on mouse chromosome 19. Ly2 and Ly3 are on mouse chromosome 6. Ly5 is on mouse chromosome 1. Ly6 is on mouse chromosome 15.

Type 1 cystatins are also called stefins which function as intracellular thiol protease inhibitors. Cystatin-B protein is able to form a dimer stabilized by noncovalent forces, inhibiting papain and cathepsins l, h and b. CSTB protein protects proteases leakage from lysosomes. Mutations in Stefin-B gene cause primary defects in patients with progressive myoclonic epilepsy (EPM1), a degenerative disease of the central nervous system. CSTB is overexpressed & elevated in the serum of HCC patients. Cystatin-B in vivo has a polymeric structure which is sensitive to the redox environment. Cystatin-B inhibits bone resorption by down-regulating intracellular cathepsin K activity despite increased osteoclast survival. Protein and mRNA levels of stefin B are significantly lower in atypical benign meningiomas. Stefins-A & Stefin-B which belong to the type-1 Cystatins, are up-regulated in lung tumours and thus able to counteract harmful tumour-associated proteolytic activity. Human stefin-A & Stef

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.

Cellular nucleic acid-binding protein (CNBP) is a nucleic-acid binding protein with seven zinc-finger domains, which has a preference for binding single stranded DNA and RNA. CNBP serves in cap-independent translation of ornithine decarboxylase mRNA, and also in sterol-mediated transcriptional regulation. The expansion of A CCTG in CNBP protein’s first intron results in myotonic dystrophy type 2.

CASQ2 belongs to the calsequestrin family and is localized to the sarcoplasmic reticulum in cardiac and slow skeletal muscle cells. CASQ2 is a calcium binding protein that stores calcium for muscle function. The discharge of calcium bound to CASQ2 through a calcium release channel activates muscle contraction. CASQ2 binds 40 to 50 moles of calcium. CASQ2 mutations result in stress-induced polymorphic ventricular tachycardia, also called catecholaminergic polymorphic ventricular tachycardia 2 which is known fir its bidirectional ventricular tachycardia that causes cardiac arrest.

RAC2 is a small signaling G protein/GTPase which is part of the RAS superfamily of small GTP-binding proteins which regulate cell growth, actin cytoskeletal organization, cell proliferation, survival, cell cycle progression, gene transcription rgulation and the activation of protein kinases. RAC2 cycles between an active gtp-bound and inactive gdp-bound state. In active state, RAC2 binds to a variety of effector proteins to regulate cellular responses, such as secretory processes, phagocytose of apoptotic cells and epithelial cell polarization. RAC2 is involved in the regulation of the nadph oxidase.

Calpain, Small Subunit 1 (CAPNS1) belongs to the calpain small subunit family. Calpains are a ubiquitous, well-conserved family of calcium-dependent, cysteine proteases, widely distributed in mammalian cells. Calpain families are implicated in neurodegenerative processes, considering that their activation can be triggered by calcium influx and oxidative stress. Calpains function as heterodimers, comprising a specific large catalytic subunit (calpain 1 subunit in Calpain I, and calpain 2 subunit in Calpain II), and a common small regulatory subunit encoded by the CAPNS1 gene. The CAPNS1 protein is vital for the stability and function of both calpain heterodimers, whose proteolytic activities influence numerous cellular functions including apoptosis, proliferation, migration, adhesion, and autophagy.

TUBG1 belongs to the tubulin superfamily. TUBG1 is localizes to the centrosome and binds to microtubules to create the gamma-tubulin ring complex. TUBG1 facilitates the microtubule nucleation and is essential for microtubule formation and progression of the cell cycle.

PCNA is located in the nucleus and is a cofactor of DNA polymerase delta. PCNA acts as a homotrimer and helps elevate the processivity of leading strand synthesis during DNA replication. In reaction to DNA damage, PCNA is ubiquitinated and takes part in the RAD6-dependent DNA repair pathway. 2 transcript variants encoding the same protein have been found for PCNA gene. Pseudogenes of this PCNA gene have been described on chromosome 4 and on the X chromosome. PCNA is expressed during late G1- phase, S-phase of mitosis and persists until the end of the M-phase because of its long biological half-life. PCNA is induced by UV irradiation.

Frataxin is a mitochondrial iron binding protein that is part of the FRATAXIN family. Frataxin functions in regulating mitochondrial iron transport and respiration. The expansion of intronic trinucleotide repeat GAA results in Friedreich ataxia. Frataxin plays a role in iron homeostasis. Frataxin is an anti-apoptotic protein which prevents mitochondrial damage and reactive oxygen species (ROS) production.

Otubain 1 (OTUB1) belongs to the ovarian tumor (OUT) superfamily of predicted cysteine proteases and inhibits cytokine gene transcription in the immune system through its interaction with a ubiquitin protease and E3 ubiquitin ligase. OTUB1 is a highly specific ubiquitin iso-peptidase, it cleaves ubiquitin from branched poly-ubiquitin chains but not from ubiquitinated substrates. OTUB1 is believed to work in specific ubiquitin-dependent pathways, possibly by providing an editing function of polyubiquitin chain growth. OTUB1 is a hydrolase that removes conjugated ubiquitin from proteins in vitro and may therefore have a significant regulatory role in the level of protein turnover by preventing degradation. Additionally, OTUB1 is a regulator of T-cell anergy, a phenomenon that occurs when T-cells are rendered impassive to antigen re-challenge and no longer respond to their cognate antigen. OTUB1 acts via its interaction with RNF128/GRAIL, which is an essential inductor of CD4 T-cell anergy.

Actin Beta (ACTB) is one of 6 different actin isoforms which have been identified in humans. ACTB is one of the 2 nonmuscle cytoskeletal actins. Actins are highly conserved proteins which are involved in cell motility, structure and integrity. Alpha actins are a key component of the contractile apparatus.

Inhibitor of Growth Family, Member 2 (ING2) belongs to the inhibitor of growth (ING) family. ING family members associate with and modulate the activity of histone acetyltransferase (HAT) and histone deacetylase (HDAC) complexes and serve in DNA repair and apoptosis. ING2 appears to be involved in p53/TP53 activation and p53/TP53-dependent apoptotic pathways, most likely by enhancing acetylation of p53/TP53. ING2 is a component of an mSin3A-like corepressor complex, which is probably involved in deacetylation of nucleosomal histones. ING2 activity is modulated by binding to phosphoinositides (PtdInsPs).

Calnexin (CANX) belongs to the calnexin family of molecular chaperones. Calnexin is a calcium-binding, ER-associated protein that interacts briefly with newly synthesized N-linked glycoproteins, facilitating protein folding and assembly. Calnexin may also have a key role in the quality control of protein folding by retaining incorrectly folded protein subunits within the ER for degradation. Calnexin grants long-term protection of wild-type Shaker protein from ER-associated degradation. Polypeptide substrate recognition by Calnexin requires specific conformations of the Calnexin protein. Calnexin dwindles with aging and might contribute to a cytoprotection in an array of human age-related diseases.

Tumor necrosis factor is a cytokine involved in systemic inflammation and is a member of a group of cytokines that all stimulate the acute phase reaction. TNF is mainly secreted by macrophages.
TNF causes apoptotic cell death, cellular proliferation, differentiation, inflammation, tumorigenesisand viral replication, TNF is also involved in lipid metabolism, and coagulation. TNF's primary role is in the regulation of immune cells.
Dysregulation and, in particular, overproduction of TNF have been implicated in a variety of human diseases- autoimmune diseases, insulin resistance, and cancer.