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The La protein is a 47 kDa polypeptide that frequently acts as an autoantigen in systemic lupus erythematosus and Sjogren's syndrome patients. La is involved in various aspects of RNA metabolism, including binding and protecting 3-prime UUU(OH) elements of newly RNA polymerase III - transcribed RNA, processing 5-prime and 3-prime ends of pre-tRNA precursors, acting as an RNA chaperone, and binding viral RNAs linked to hepatitis C virus. It occurs in both the nucleus and the cytoplasm, where it assumes different roles. In the nucleus, La protein facilitates the production of tRNAs, acting as an RNA polymerase III (RNAP III) transcription factor by attaching to the U-rich 3'UTR of nascent transcripts, aiding in their folding and maturation. In the cytoplasm, La protein facilitates the translation of specific mRNAs, acting as a translation factor. As an RNA binding protein (RBP), La protein associates with subsets of mRNAs which contain a 5'-terminal oligopyrimidine (5'TOP) motif known to direct protein synthesis. The binding of La protein to particular classes of RNA molecules regulates their downstream processing, guards them from endonuclease digestion, and organizes their export from the nucleus. La/SS-B appears to be readily disposed to proteolysis, which results in many smaller (42kD, 320, and 270) nevertheless still immunoreactive polypeptides. La/SS-B antigen is strongly conserved across species. Anti-La/SS-B autoantibodies were originally found as precipitating autoantibodies in sera of Sjogren's Syndrome patients and referred to as SjT. Anti-La/SS-B precipitins are most frequently found in Sjogren's Syndrome, Systemic Lupus Erythematosus (SLE) and Subacute Cutaneous Lupus. Also, there seems to be a correlation between anti-La/SS-B and the absence of nephritis in SLE patients.

Inhibitor of DNA Binding 1 (ID1) is a helix-loop-helix protein which can form heterodimers with members of the basic HLH family of transcription factors. ID1 is lacking DNA binding activity and thus can inhibit the DNA binding and transcriptional activation ability of basic HLH proteins with which it interacts. ID1 participates in cell growth, senescence, and differentiation.

SDCBP is a multifunctional intracellular adapter protein. SDCBP protein has tandemly repeated PDZ domains which react with the FYA (phe-tyr-ala) carboxyterminal amino acid sequence of the syndecans. SDCBP is has a role in organization of protein complexes in the plasma membranes, regulation of B-cell development, activation of transcription factors, intracellular trafficking and cell-surface targeting, synaptic transmission, and axonal outgrowth.

CYR61 is a growth factor-inducible, immediate-early gene that has multifaceted activities in various cancers. CYR61 is a secreted, cysteine-rich, binding protein which is encoded by a growth factor-inducible immediate-early gene. Acting as an extracellular, matrix-associated signaling molecule, CYR61 promotes the adhesion of endothelial cells through interaction with integrin and enhances growth factor-induced DNA synthesis in the same cell type.

rGFP, also known as Green Fluorescent Protein, is a protein produced by the jellyfish (Aequorea Victoria) that produces bioluminescence in the green zone of the noticeable spectrum. Green Fluorescent Protein is a useful and ubiquitous instrument for producing chimeric proteins, where it functions as a fluorescent protein tag. rGFP is expressed in most known cell types and is used as a noninvasive fluorescent marker in living cells and organisms. Green Fluorescent Protein permits a broad range of applications where it has functioned as a cell lineage tracer, reporter of gene expression, or as a measure of protein-protein interactions.

NCBP2 is a part of the nuclear cap-binding protein complex (CBC) that binds to the monomethylated 5'' cap of nascent pre-mRNA in the nucleoplasm. NCBP2 protein has an RNP domain usually located in RNA binding proteins, and contains the cap-binding activity. CBC promotes pre-mRNA splicing, 3''-end processing, RNA nuclear export, and nonsense-mediated mRNA decay.

CAB39 protein and STE20-related adaptor-alpha pseudo kinase, form a regulatory complex that is able of stimulating the activity of the LKB1 tumor suppressor protein kinase. CAB39 takes part as a scaffolding component of the STK11/STRAD complex and regulates STK11 activity and cellular localization.

GHBP is a transmembrane receptor for GH. Binding of GH to the receptor leads to receptor dimerization and the activation of an intra- and intercellular signal transduction pathway leading to growth. A common alternate allele of this gene, called GHRd3, lacks exon three and has been well-characterized. Mutations in this gene have been associated with Laron syndrome, also known as the GH insensitivity syndrome (GHIS), a disorder characterized by short stature. Other splice variants, including one encoding a soluble form of the protein (GHRtr), have been observed but have not been thoroughly characterized.

FKBP1A is a 12kDa protein initialy discovered onin immune cells on the basis of its capability to bind and mediate the intracellular effect of the immunosuppressant FK506. FKBP1A is also known to mediate the action of Rapamycin-immunosuppressive agent. FKBP1A is part of the family of immunophilins, which have in common high affinity for immunosuppressant drugs and a peptidyl-prolyl cis-trans isomerase (PPIase). Activity which participates in folding of proline-containing protein. In the absence of immunosuppressive ligands, FKBP1A is involved in intracellular calcium regulation by associating with 3 types of Ca2+ release channel complexes: skeletal ryanodine receptors, cardiac ryanodine receptors and the inositol 1,4,5-triphosphate receptor. FKBP1A also interact with TGF-b type I receptor exerting an inhibitory effect on the TGF-b signaling pathway. FKBP12 plays a role in modulation of ryanodine receptor isoform-1 (ryr-1), a component of the calcium release channel of skeletal muscle sarcoplasmic reticulum. FKBP1A increase the folding of proteins and catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides.

A natural cytotoxicity receptor (NCR) NKp46 has been shown to represent a novel NK cell-specific molecule involved in human NK cell activation. The natural cytotoxicity receptors (NCRs) are a recently characterized family of Ig-like activation receptors that appear to be major triggering receptors in tumor cell recognition. The three known NCRs include NKp46 and NKp30, which are expressed on circulating NKcells, and NKp44, which is expressed only on activating NK cells. NKp46 has been implicated in NK cell-mediated lysis of several autologous tumor cells, pathogen-infected cell lines and mononuclear phagocytes infected with an intracellular bacterium. The Lysis of tumor cells by NK-cells involves recognition by NKp46 of heparan sulfate moieties of membrane heparan sulfate proteoglycans. Furthermore, NKp46 is a surface receptor involved in NK-cell cell death by apoptosis. NKp46 has two extracellular Ig-like domains followed by a ~40 residue stalk region, a type I transmembrane domain, and a short cytoplasmic tail. The extracellular Ig-like domain of NKp46 (22-255aa) is purified by FPLC gel-filtration chromatography, after refolding of the isolated inclusion bodies in a redox buffer. In addition, engagement of the antigen with the monoclonal antibody stimulates intracellular calcium levels and the synthesis of cytokines. CD59 is an NKp46 coreceptor (by physical association) together they activate cytotoxicity of human NK-cells, their engagement results in tyrosine phosphorylation of CD3-zeta chains associated with NKp46. Reduced cell surface expression of NKp46 and other NK-cell receptors is linked to the impaired NK-cell cytolytic function in viremic HIV-1 infection.

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.

MAD2L1-binding protein (MAD2L1BP) is a member of the MAD2L1BP family.MAD2L1BP is a binding protein of the MAD2 mitotic arrest deficient-like 1 (MAD2/MAD2L1). MAD2 is a fundamental factor of the spindle checkpoint which delays the onset of anaphase until all the kinetochores are connected to the spindle. The MAD2L1BP protein acts to curb the spindle checkpoint and allow mitosis to proceed through anaphase by binding MAD2L1 once it dissociated from the MAD2L1-CDC20 complex. For the duration of the cell cycle, MAD2L1BP levels increase and then remain constant until late mitosis after which they drop.

SOS1, also known as Gingival Fibromatosis, is a Ras & Rac guanine nucleotide exchange factor. SOS1 is comprised of a number of significant domains. The REM and CDC25 domains provide the catalytic activity of SOS1 towards Ras and the histone fold DH/PH (Dbl homology & Pleckstrin homology) domains function, in tandem, to stimulate GTP/GDP exchange for Rac. Moreover, binding of GTP activates Ras proteins, and subsequent hydrolysis of the bound GTP to GDP and phosphate inactivates signaling by these proteins. GTP binding can be catalyzed by guanine nucleotide exchange factors for RAS, and GTP hydrolysis can be enhanced by GTPase-activating proteins.

Thyroglobulin (TG) represents one of the main autoantigenic targets in autoimmune thyroid disease of humans. TG is a large globular dimeric glycoprotein with a total molecular weight of 660 kDa, which occupies a key precursor role in the biosynthesis of the thyroid hormones. Approximately 75% of the total protein content of the thyroid follicle consists of TG. The thyroid gland uses the Thyroglobulin in order to produce the thyroid hormones thyroxine (T4) and triiodothyronine (T3). Thyroglobulin is produced by the thyroid epithelial cells (thyrocytes) which form spherical follicles. Thyroglobulin is subsequently secreted and stored in the follicular lumen.
Patients with Hashimoto's thyroiditis or Graves' disease, frequently develop antibodies against Thyroglobulin. Tg-specific antibodies help in the diagnosis of the above diseases, however they also may be present in apparently healthy euthyroid individuals. Blood Thyroglobulin levels can be used as a tumor marker for certain kinds of thyroid cancer, and the may also be elevated in cases of Graves' disease.

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.

RNA Binding Motif Protein 11 (RBM11) which contains 1 RNA recognition motif is a part of the RBM family. The RBM gene family encodes proteins with an RNA binding motif which participate in the modulation of apoptosis. RBM11 is expressed in testis, kidney, spleen, brain, spinal cord and mammary gland and can be found as 2 isoforms produced by alternative splicing.

PAIP2 has a role as a repressor in the regulation of translation initiation of poly(A)-containing mRNAs. PAIP2 inhibitory activity on translation is mediated through its action on PABPC1. PAIP2 displaces the interaction of PABPC1 with poly(A) RNA and competes with PAIP1 for binding to PABPC1. PAIP2 association with PABPC1 results in disruption of the cytoplasmic poly(A) RNP structure organization.

RND3 is a small GTPase which is part of the Ras superfamily that controls the association of the actin cytoskeleton in reaction to extracellular growth factors. RND3 activity causes a decrease in stress fibers and an increase in cell migration, at least in part through regulation of the Rho-dependent kinase ROCK1. RND3 inhibits DNA-damage induced apoptosis and cell cycle arrest. RND3 binds GTP and is resistant to Rho-specific GTPase-activating proteins.

Antigen 85A is a member of the antigen 85 complex (Antigen 85A, B, C). The enzymes of the antigen 85 complex have mycolyltransferase activity and catalyze the synthesis of the very rich glycolipid of the mycobacterial cell wall, the cord factor (trehalose 6,6'-dimycolate, TDM). The cord factor is vital for the integrity of the mycobacterial cell wall and pathogenesis of the bacillus. TDM is synthesized from two molecules of trehalose-6'-monomycolate (TMM) by Antigen 85A.

Insulin-like Growth Factor-Binding Protein 7 (IGFBP7) is a member of the IGFBP family. IGFBP family members are all cysteine rich proteins with conserved cysteine and have an IGFBP domain, a Kazal-like domain and an Ig-like C2-type domain. IGFBP7 is expressed in a broad range of normal human tissues and it mostly shows reduced expression in cancer cell lines of prostate, breast, colon, and lung origin. IGFBP7 has a role in skeletal myogenesis by binding to IGF in a manner which inhibits IGF induced differentiation of skeletal myoblasts, without disturbing IGF induced proliferation. Moreover, IGFBP7 suppresses growth and colony formation of prostate and breast cancer cell lines via an IGF independent mechanism, which triggers a delay in the G1 phase of the cell cycle, and increased apoptosis.

Cysteine-rich PDZ-binding protein, also known as CRIPT, takes part in the cytoskeletal anchoring of DLG4 in excitatory synapses.

RBP5 is a member of the Retinol-binding proteins family. Estimation of retinol-binding protein is used to determine visceral protein mass in nutritional studies related to health. RBP5 has a higher expression in the adult kidney and liver and to a lesser extent in the adult and fetal spleen, adult lymph nodes and appendix, and fetal liver and kidney. RBP5 expression is strongly decreased in hepatocellular carcinoma tissues.