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HIV-1 Nef is anessential factor for efficient viral replication and pathogenesis and therefore is produced shortly after virus infection. HIV-1 Nef is also facilitates virus replication and enhances virions infectivity. Nef exerts pleiotropic effects: decreases cell surface CD4 antigen by interacting with the Src family kinase LCK, down-modulates surface MHC-I molecules and protects the infected cell from apoptosis in order to keep it alive until the next virus generation is mature. Nef protein bypasses host T-cell signaling byinducing a trascriptional program almost identical to that of anti-CD3 cell activation.

RASSF1A is a protein similar to the RAS effector proteins. Loss or altered expression of the RASSF1A gene has been linked to the pathogenesis of a variety of cancers, which suggests the tumor suppressor function of the RASSF1A gene. The inactivation of the RASSF1A gene was found to be interconnected with the hypermethylation of its CpG-island promoter region. The RASSF1A protein was found to interact with DNA repair protein XPA. RASSF1A was also shown to inhibit the accumulation of cyclin D1, and thus induce cell cycle arrest.

IGFBP6 plays a role in lipoprotein assembly and dietary cholesterol absorption. in addition to its acyltransferase activity, it may act as a ligase. may provide cholesteryl esters for lipoprotein secretion from hepatocytes and intestinal mucosa.

NAT6 is an enzyme that catalyzes the transfer of acetyl groups from acetyl-CoA to acrylamines. NAT6 is located mainly in the cytoplasm and its activity has been recognized by its feasibility to acetylate the N-terminus of proteins using a ping-pong-like mechanism and by its substrate specificity. Given that the NAT6 gene maps to the chromosomal region 3p21.3, which includes at least one tumor suppressor gene, the function of NAT6 plays an important role in cancer.

MAPK11 belongs to the MAP kinase family and is most associated with p38 MAP kinases (MAPKs). MAPKs are activated mainly as a reaction to cellular stress and inflammatory cytokines, and inhibitors that target the MAPK14 and MAPK11 have demonstrated ability to cure inflammatory disease. MAPK11 cooperates with HDAC3 and Promyelocytic leukemia protein and takes part in a signal transduction pathway which is activated by alterations in the osmolarity of the extracellular environment, by environmental stress, or by cytokines.

Akt1, also known as Akt or else protein kinase B (PKB) is an important molecule in mammaliancellular signaling. In humans, there are three genes in the "Akt family": Akt1, Akt2, and Akt3. Moreover, these enzymes are members of the serine/threonine-specific protein kinase family (EC2.7.11.1). Akt1 is involved in cellular survival pathways, by inhibiting apoptoticprocesses. Akt1 is also able to induce protein synthesis pathways, and is therefore a key signaling protein in the cellular pathways which lead to skeletal muscle hypertrophy, and general tissue growth. Since it can block apoptosis, and thereby promote cell survival, Akt1 has been implicated as a most important factor in numerous types of cancer. Akt (now also called Akt1) was at first identified as the oncogenein the transforming retrovirus, AKT8.

Serine/arginine-rich splicing factor 1 (SFRS1) belongs to the arginine/serine-rich splicing factor protein family, and functions in both constitutive and alternative pre-mRNA splicing. SFRS1 binds to pre-mRNA transcripts and components of the spliceosome, and can either initiate or inhibit splicing depending on the position of the pre-mRNA binding site. The ability of SFRS1 to activate splicing is controlled by phosphorylation and interactions with other splicing factor associated proteins.

GABARAPL2 takes part in intra Golgi traffic and modulates intra Golgi transport by coupling between NSF activity and SNAREs activation. GABARAPL2 first stimulates the ATPase activity of NSF which in turn stimulates the association with GOSR1.

Human thyrostimulin ranks among the glycoprotein hormone family. These hormones consist of two subunits, the common alpha- and specific beta-subunits, which associate noncovalently to form a heterodimer. The alpha-subunit combines with four distinct beta-subunits giving rise to four biologically active hormones in human: FSH, LH, TSH, and CG. FSH, LH, and TSH, mainly expressed in the anterior pituitary, are essential for coordinated endocrine regulation in the hypothalamus- pituitary axis and show to activate specific G protein–coupled receptors in the thyroid (TSH receptor) and gonads (LH and FSH receptors), respectively.
The heterodimeric glycoprotein hormones have only been identified in vertebrates and are highly conserved in organisms from primitive rayfin fish (Chondrostei) to human in both primary sequences and functional characteristics.
Corticotroph-derived glycoprotein hormone (CGH), also referred to as thyrostimulin, is a noncovalent heterodimer of glycoprotein hormone alpha 2 (GPHA2) and glycoprotein hormone beta 5 (GPHB5).
Recombinant A2/B5 heterodimeric glycoproteins activates human TSH receptors, but not LH and FSH receptors, and shows high affinity to TSH receptors in a radioligand receptor assay. The heterodimer also stimulates cAMP production and thymidine incorporation by cultured thyroid cells and increases serum thyroxine levels in TSH-suppressed rats in vivo. This new heterodimeric glycoprotein hormone was named as thyrostimulin based on its thyroid-stimulating activity. The expression of thyrostimulin in the anterior pituitary known to express TSH receptors suggested a paracrine mechanism.

Transcription factor MafG (MAFG) is a member of the Maf family. Given that they lack a putative transactivation domain, the small Mafs act as transcriptional repressors when they dimerize amongst themselves. Nevertheless, they seem to function as transcriptional activators by dimerizing with other (generally larger) basic-zipper proteins and engaging them to specific DNA-binding sites. Small Maf proteins heterodimerize with Fos and may function as competitive repressors of the NF-E2 transcription factor.

Glycophorins A & B (GYPA &GYPB) are the main sialoglycoproteins of the human erythrocyte membrane which carry the antigenic determinants for the MN and Ss blood groups. Along with the M or N and S or s antigens which normally occur in all populations, approximately 40 related variant phenotypes were identified. These variants comprise all the variants of the Miltenberger complex and some isoforms of Sta, as well as Dantu, Sat, He, Mg, and deletion variants Ena, S-s-U- and Mk. GYPA is significant for the function of SLC4A1 and is necessary for high activity of SLC4A1. GYPA is involved in translocation of SLC4A1 to the plasma membrane. GYPA is also a receptor for: the influenza virus, Plasmodium falciparum erythrocyte-binding antigen 175 (EBA-175); binding of EBA-175 is dependent on sialic acid residues of the O-linked glycans and is also a receptor for Hepatitis A virus (HAV).

IL-1 alpha is produced by activated macrophages.IL-1 alpha stimulates thymocyte proliferation by inducing il-2 release, b-cell maturation and proliferation, and fibroblast growth factor activity. IL1A proteins take part in the inflammatory response, being identified as endogenous pyrogens, and stimulate the release of prostaglandin and collagenase from synovial cells.

SARS Coronavirus is an enveloped virus containing three outer structural proteins, namely the membrane (M), envelope (E), and spike (S) proteins. Spike (S)-glycoprotein of the virus interacts with a cellular receptor and mediates membrane fusion to allow viral entry into susceptible target cells. Accordingly, S-protein plays an important role in virus infection cycle and is the primary target of neutralizing antibodies.It has recently been shown that SARS is caused by a human coronavirus. Human coronaviruses are the major cause of upper respiratory tract illness in humans, such as the common cold. Coronaviruses are positive-stranded RNA viruses, featuring the largest viral RNA genomes known to date (27-31 kb). The first step in coronavirus infection is binding of the viral spike protein, a 139-kDa protein, to certain receptors on host cells. The spike protein is the main surface antigen of the coronavirus. The most prominent protein in the culture supernatants infected with SARS virus is a 46 kDa nucleocapsid protein. This suggests that the nucleocapsid protein is a major immunogen that may be useful for early diagnostics.

ARF6 is a part of the ADP ribosylation factor family of GTP-binding proteins. ARF6 is restricted to the plasma membrane, and controls vesicular trafficking, remodeling of membrane lipids, and signaling pathways which lead to actin remodeling. Furthermore, ARF6 is a key player in conservation of organelle integrity, assembly of coat proteins and activation of phospholipase D.

SLAM family member 6 (SLAMF6) is a member of the SLAM family of immune cell receptors. SLAMF6 is a unique receptor on T cells which, when triggered potentiates T cell expansion in a CD28-independent manner. SLAMF6 has a high expression on NK-, T-, and B cells. SLAMF6 exhibits homotypic interactions and can connect with adaptor molecules such as SAP to alter immune cell function.

SNRPF is a member of the snRNP Sm proteins family. There are at least seven isoforms, E, F, G, D1, D2, D3 and B/B. This type of common proteins have a crucial part in the biogenesis of the snRNPs. Moreover, they represent the major targets for the so-called anti-Sm auto-antibodies that are diagnostic for systemic lupus erythematosus (SLE). SNRPF assist in the cytoplasmic construction of the UsnRNPs by binding to aconserved Sm site on UsnRNA and forming a stable snRNP core complex.

GCSAM is a protein which functions in signal transduction pathways and whose expression raises in germinal cell lymphomas. GCSAM contains a putative PDZ-interacting domain, an immunoreceptor tyrosine-based activation motif (ITAM), and two putative SH2 binding sites. In B cells, GCSAM expression is particularly induced by interleukin-4.

GPN-loop GTPase 1 (GPN1) is a member of the GPN-loop GTPase family. GPN1 is a guanosine triphosphatase enzyme which has a role in DNA repair and may function in activation of transcription. Small GTPases, which share a biochemical mechanism, act as binary molecular switches and function in the cell is nucleocytoplasmic transport of both proteins and RNA. In addition, GPN1 establishs an interface between the RNA polymerase II enzyme and chaperone/scaffolding protein, proposing that it is essential to connect RNA polymerase II to regulators of protein complex formation. GPN1 may also be involved in nuclear localization of XPA.

Drosophila that have mutations in their MAGOH gene produce progeny with defects in germplasm assembly and germline development. MAGOH, the human homolog of Drosophila mago nashi, is necessary for embryo development. In mammals, mRNA expression is not limited to the germ plasm, but is expressed ubiquitously in adult tissues and is induced by serum stimulation of quiescent fibroblast.

PTB domain-containing engulfment adapter protein 1 (GULP1) is an evolutionarily conserved adaptor protein essential for efficient phagocytosis of apoptotic cells by phagocytes. Furthermore, GULP1 helps modulate cellular glycosphingolipid and cholesterol transport. In addition, GULP1 may have a role in the internalization and endosomal trafficking of various LRP1 ligands, such as PSAP. Increased cytoplasmic levels of GULP1 are linked with increases in cellular levels of GTP-bound ARF6.

FGF-23 is a member of the fibroblast growth factor (FGF) family. FGF family members possess broad mitogenic and cell survival activities and are involved in a variety of biological processes including embryonic development, cell growth, morphogenesis, tissue repair, tumor growth and invasion. FGF-23 inhibits renal tubular phosphate transport. The FGF-23 gene was identified by its mutations associated with autosomal dominant hypophosphatemic rickets (ADHR), an inherited phosphate wasting disorder. Abnormally high level expression of FGF-23 was found in oncogenic hypophosphatemic osteomalacia (OHO), a phenotypically similar disease caused by abnormal phosphate metabolism. FGF-23 mutations have also been shown to cause familial tumoral calcinosis with hyperphosphatemia.

Activins are homodimers or heterodimers of the different β subunit isoforms, part of the TGFβ family. Mature Activin A has two 116 amino acids residues βA subunits (βA-βA). Activin displays an extensive variety of biological activities, including mesoderm induction, neural cell differentiation, bone remodelling, haematopoiesis, and reproductive physiology. Activins takes part in the production and regulation of hormones such as FSH, LH, GnRH and ACTH. Cells that are identified to express Activin A include fibroblasts, endothelial cells, hepatocytes, vascular smooth muscle cells, macrophages, keratinocytes, osteoclasts, bone marrow monocytes, prostatic epithelium, neurons, chondrocytes, osteoblasts, Leydig cells, Sertoli cells, and ovarian granulosa cells.

a-Synuclein (amino acids 1-140), an acidic neuronal protein of 140 amino acids, is extremely heat-resistant and is natively unfolded with an extended structure primarily composed of random coils. a-synuclein has been suggested to be implicated in the pathogenesis of Parkinson’s disease and related neurodegenerative disorders, and more recently, to be an important regulatory component of vesicular transport in neuronal cells. Moreover, recent studies have shown that a-synuclein has chaperone activity and that this activity is lost upon removing its C-terminal acidic tail (amino acids 96-140).