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Guanosine-3',5'-bis(diphosphate)-pyrophosphohydrolase MESH1 (HDDC3) contains an active site for ppGpp hydrolysis and a conserved His-Asp-box motif for Mn(2+) binding. In accordance with its structure, HDDC3 effectively catalyzes the hydrolysis of guanosine 3',5'-diphosphate (ppGpp) both in vitro and in vivo. In addition, HDDC3 suppresses SpoT-deficient lethality and RelA-induced delayed cell growth in bacteria.

The 14-3-3 family of proteins plays a key regulatory role in signal transduction, checkpoint control, apoptotic and nutrient-sensing pathways. 14-3-3 proteins are highly conserved and ubiquitously expressed. There are at least seven isoforms that have been identified in mammals. The 14-3-3gamma, a subtype of the 14-3-3 family of proteins, was thought to be brain and neuron-specific. It has been shown to interact with RAF1 and protein kinase C, proteins involved in various signal transduction pathways.

Since April 2012, cases of the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) have been identified in various countries. Coronaviruses are the cause of the common cold, SARS (severe acute respiratory syndrome) and other severe illnesses with high mortality rates, all are classified into coronavirus family. MERS-CoV is a new type of SARS found in the coronavirus family causing severe pneumonia with sudden and serious respiratory illness with high mortality rates as well. Since January 27th 2015, the WHO has reported 956 human cases, including 351 deaths. More cases of the new coronavirus strain are expected. Like in other coronaviruses, large surface spike glycoprotein is a central structural protein of this virus; it is located above the virion surface to bind and enter into the target cell. Spike protein has 2 domains- S1 and S2. The S1 domain is responsible for cellular tropism and interaction with target cell, while the S2 domain is responsible for membrane fusion. The C-terminal of S1 domain contains a receptor binding domain, and is also a potential target for vaccine development and an antigen for diagnosis.

Protein Phosphatase 2, Regulatory Subunit A Alpha, also known as PPP2R1A is part of the PPP family of phosphatases, which regulates a diversity of vital cellular processes. PPP2R1A subunit, PR65, functions as a scaffolding molecule which coordinates the assembly of the catalytic subunit and a variable regulatory B subunit. PPP2R1A is essential for proper chromosome segregation as well as for centromeric localization of SGOL1 in mitosis. Furthermore, PPP2R1A phosphorylation is an in vivo mechanism which regulates the PP2A signaling complex as well as increasing the PP2A activity in heart failure.

PEX19 is vital for peroxisome biogenesis in Saccharomyces cerevisiae. PEX19 is limited to the outer surface of peroxisomes in liver cells and is has a part in the early stage of peroxisome membrane assembly, prior to the import of matrix protein.

Severe acute respiratory syndrome (SARS) has a new causative agent identified as Coronavirus. SARS Associated Coronavirus Spike is one of the main surface antigens of Coronavirus, making it one of the main candidates for vaccines. Diseases caused by Coronaviruses are usually controlled by CD8 T cells.

PCK1 is a central regulating point for the regulation of gluconeogenesis. PCK1 has a vital part in this process by stimulating hepatic glucose production. The expression of PCK1 is controlled by cAMP, glucocorticoids, diet etc. Modulation of the signals controlling PCK1 levels offers a possible therapeutic tactic to the treatment of Diabetes and subsequently obesity.

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.

VPS25 contains the ESCRT-II complex (endosomal sorting complex required for transport II), that is needed for sorting of endosomal cargo proteins into MVBs and multivesicular body (MVB) formation. The MVB pathway facilitates transport of transmembrane proteins into the lumen of the lysosome for degradation. The ESCRT-II complex takes part in the recruitment of the ESCRT-III complex which is involved in transcription regulation, probably through its collaboration with ELL.

Recombinant Human Sonic Hedgehog is part of a small group of secreted proteins that are vital for development in both vertebrates and invertebrates. 3 mammalian hedgehog genes (sonic, desert, Indian) share about 60% homology. The Human Sonic Hedgehog is 99% homologous to the mouse gene. Sonic HedgeHog is a protein that is vital in guding the early embryo. It has been associated as the major inductive signal in patterning of the ventral neural tube, the anterior-posterior limb axis, and the ventral somites. Sonic HedgeHog binds to the patched receptor, which functions in association with smoothened, to activate the transcription of target genes. In the absence of sonic HedgeHog, patched receptor represses the constitutive signaling activity of smoothened. Sonic HedgeHog also regulates another factor, the gli oncogene. Sonic HedgeHog intercellular signal is essential for a various patterning events during development: signal produced by the notochord that induces ventral cell fate in the neural tube and somites, and the polarizing signal for patterning of the anterior-posterior axis of the developing limb bud. Sonic HedgeHog exhibits both floor plate- and motor neuron-inducing activity. Mutations in a long-range Sonic HedgeHog enhancer located in an intron of the limb region 1 gene result in preaxial polydactyly.

Platelet factor-4 is a 70-amino acid protein that is released from the alpha-granules of activated platelets.PF4’s major physiologic role appears to be neutralization of molecules on the endothelial surface of blood vessels, thereby inhibiting local antithrombin III 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 chemokine family. Furthermore, it is used as an inhibitor in the angiogenesis during tumor therapy.

CAMK4 is a member of the serine/threonine protein kinase family, and of the Ca(2+)/calmodulin-dependent protein kinase subfamily. CAMK4 is a multifunctional serine/threonine protein kinase with restricted tissue distribution which is associated to transcriptional regulation in lymphocytes, neurons and male germ cells.

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. By injecting soluble RANKL, novel osteopenia model mice were established in only 50 hours. Degree of bone loss can be controlled by changing doses of sRANKL. RANKL can be used in establishing osteopenia model for in vivo screening of drugs for osteoporosis, determination of effect and mechanism, evaluation of bone anabolic drugs.

Calmodulin Like 5, also known as CALML5 is a part of the calmodulin family of calcium binding proteins. CALML5 undergoes a conformational change as a result of binding calcium. CALML5 is taking part in terminal differentiation of keratinocytes and encodes a calcium binding protein expressed in the epidermis.

PNP is a member of the PNP/MTAP phosphorylase family of proteins. PNP catalyzes the reversible phosphorolysis of ribonucleosides and 2’-deoxyribonucleosides with specificity for guanine, hypoxanthine and their analogs. PNP deficiency is a rare autosomal recessive genetic disease linked to a severe defect in T-lymphocyte function and neurologic disorder in children, comprising four percent of combined immunodeficiency cases.

FABP1 (Fatty acid binding protein1) encodes the fatty acid binding protein found in liver. FABP1 is composed of ten antiparallel beta strands that form a barrel with a bigger binding pocket than the other FABPs allowing it to accommodate two fatty acid. This protein binds free fatty acids and their coenzyme A derivatives, bilirubin, and some other small molecules in the cytoplasm; it may be involved in intracellular lipid transport and metabolism.

KLF4 is a transcription factor that performs as both an activator and repressor. KLF4 is expressed mainly in erythroid tissues and found mostly in gut. KLF4 is takes part in the differentiation of epithelial cells in addition to skeletal and kidney development.

PPCDC is a member of the HFCD (homo oligomeric flavin containing Cys decarboxylase) superfamily which takes a part in the biosynthesis of coenzyme A (CoA) from pantothenate (Vitamin B). The biosynthesis of CoA from pantothenate needs several steps: the phosphorylation of pantothenate, the conversion of 4’-hosphopantothenate to 4''-phosphopantetheine, the adenylation by phosphopantetheine adenylyltransferase to form dephospho-CoA and the phosphorylation by dephospho-CoA kinase to form CoA. PPCDC is a key player in this pathway. PPCDC converts 4''-phosphopantothenate into 4''-phosphopantetheine.

2-Enoyl-Coenzyme A (CoA) Hydratase, Beta (HADHB) is the beta subunit of the mitochondrial trifunctional protein, that catalyzes the last 3 phases of mitochondrial beta-oxidation of long chain fatty acids. HADHB binds RNA and reduces the stability of various mRNAs. Mutations in HADHB cause trifunctional protein deficiency.

FABP6 also called ileal fatty acid binding protein, is part of the small family of highly conserved, cytoplasmic proteins that bind long-chain fatty acids and other hydrophobic ligands. FABP6 cytosolic protein binds bile acid. FABP6 plays a role in fatty acid uptake, transport, and metabolism. FABP6 stimulates gastric acid and pepsinogen secretion. Seems to be able to bind to bile salts and bilirubins. FABP6 expression is restricted in the small intestine to the ileum where it is involved in the enterohepatic circulation of bile acids. Alternate transcription promoters generate 2 transcript variants, encoding a 128 aa and a 177 aa residue protein. Human FABP6 isoform 2 contains 128 amino acid residues and is acetylated on Ala2. FABP6 binds together fatty acids and bile acids and is directly involved in fatty acid transport and metabolism.

SBDS is part of an extremely preserved protein family which exists from archaea to vertebrates and plants. SBDS protein functions in RNA metabolism and has a role in the biogenesis of the 60S ribosomal subunit and translational activation of ribosomes. Shwachman-Diamond syndrome is a rare autosomal recessive disorder produced by mutations in the SBDS gene.

HECT and RLD Domain Containing E3 Ubiquitin Protein Ligase 5 (HERC5) is a member of the HERC family of ubiquitin ligases, found in a cluster of HERC family genes on chromosome 4. HERC5 is a protein with a HECT domain and 5 RCC1 repeats. The HERC5 protein localizes to the cytoplasm and perinuclear region and serves as an INF-induced E3 protein ligase that mediates ISGylation of protein targets. HERC5 exhibits antiviral activity towards HIV-1, influenza A virus and human papillomavirus. HERC5 is a major E3 ligase for ISG15 conjugation. HERC5 also serves as a positive regulator of innate antiviral response in cells induced by INF. Pro-inflammatory cytokines upregulate HERC5 in endothelial cells. HERC5 is physically connected with polyribosomes, broadly modifies recently synthesized proteins in a cotranslational fashion.

SMCP is a protein-coding gene. SMCP localizes to the capsule linked with the mitochondrial outer membranes and assumed to function in the organization and stabilization of the helical structure of the sperm's mitochondrial sheath. Sperm mitochondria vary in morphology and subcellular localization from those of somatic cells. They are elongated, flattened, and arranged circumferentially construct a helical coiled sheath in the midpiece of the sperm flagellum. Diseases associated with SMCP include middle ear disease, and hard palate cancer.