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Macrophage Inflammatory Proteins (MIP) belong to the family of chemotactic cytokines known as chemokines. In humans, there are two major forms, MIP-1a and MIP-1b that are now officially named CCL3 and CCL4 respectively. Both are major factors produced by macrophages after they are stimulated with bacterial endotoxins. They activate human granulocytes (neutrophils, eosinophilsand basophils) which can lead to acute neutrophilic inflammation. They also induce the synthesis and release of other pro-inflammatory cytokines such as interleukin 1 (IL-1), IL-6 and TNF-a from fibroblasts and macrophages. The genes for CCL3 and CCL4 are both located on human chromosome 17.

PDCD1 is a cell surface membrane protein of the immunoglobulin superfamily. PDCD1 is expressed in pro-B-cells and is thought to have a role in their differentiation. In mice, expression of PDCD1 gene is induced in the thymus when anti-CD3 antibodies are injected and large numbers of thymocytes undergo apoptosis. Mice deficient for the PDCD1 gene bred on a BALB/c background developed dilated cardiomyopathy and died from congestive heart failure. These studies suggest that the PDCD1 gene product may also be important in T cell function and contribute to the prevention of autoimmune diseases.

MAK16 is a member of the MAK16 family.

The secreted polypeptide noggin, encoded by the NOG gene, binds and inactivates members of the transforming growth factor-beta (TGF-beta) superfamily signaling proteins, such as bone morphogenetic protein-4 (BMP4). By diffusing through extracellular matrices more efficiently than members of the TGF-beta superfamily, noggin may have a principal role in creating morphogenic gradients. Noggin appears to have pleiotropic effect, both early in development as well as in later stages. It was originally isolated from Xenopus based on its ability to restore normal dorsal-ventral body axis in embryos that had been artificially ventralized by UV treatment. The results of the mouse knockout of noggin suggest that it is involved in numerous developmental processes, such as neural tube fusion and joint formation. Recently, several dominant human NOG mutations in unrelated families with proximal symphalangism (SYM1) and multiple synostoses syndrome (SYNS1) were identified; both SYM1 and SYNS1 have multiple joint fusion as their principal feature, and map to the same region (17q22) as NOG. All NOG mutations altered evolutionarily conserved amino acid residues. The amino acid sequence of human noggin is highly homologous to that of Xenopus, rat and mouse.

Actin-related protein 2/3 complex subunit 2 (ARPC2), is a part of the Rho family of small GTPases and one of seven subunits of the human Arp2/3 protein complex. The Arp2/3 protein complex has been implicated in the control of actin polymerization in cells and has been conserved through evolution. Nevertheless, the exact role of the protein (the p34 subunit) has yet to be determined.

Speckle-type POZ protein (SPOP) belongs to the Tdpoz family containing one N-terminal MATH (Meprin and TRAF homology) domain and one C-terminal BTB/POZ domain. SPOP inhibits IPF1/PDX1 transactivation of established target promoters, may be by recruiting a repressor complex. SPOP is involved in ubiquitinylation and protein degradation as a result of an interaction with CUL-3.

Vimentin expression in human malignant glioma cells depends on cellular density, algorithms of drug delivery and chemo/radio treatment. Vimentin and detyrosinated microtubules provide structural support for the extensive microtentacles observed in detached tumor cells and a mechanism to promote successful metastatic spread. Primary colorectal carcinomas display aberrant expression of vimentin, and have activated Notch and TGFbeta signaling pathways. Vimentin is a strong arterial substrate for transglutaminases. Transglutaminase-mediated vimentin dimerization results in a novel unifying pathway by which vasodilatory and remodeling responses may be regulated. Ablation of vimentin expression inhibits migration and invasion of colon and breast cancer cell lines. Vimentin is the main intermediate filament protein in mesenchymal cells and is therefore of value in the differential diagnosis of undifferentiated neoplasms.

cAMP-dependent protein kinase inhibitor beta (PKIB) belongs to the cAMP-dependent protein kinase inhibitor family. PKIB may interact with the catalytic subunit of cAMP-dependent protein kinase and function as a competitive inhibitor.

Delta-Like4 or DLL4 is implicated in the Notch signaling transduction as Notch ligand. DLL4 down regulates endothelial cell proliferation, migration and angiogenic sprouting. DLL4 is crucial for retinal progenitor proliferation &furthermore required for suppressing rod fates in late retinal progenitors & for proper generation of other retinal cell types. Also, at some stages in the spinal cord neurogenesis, DLL4 inhibits V2a interneuron fate.

BCA-1 is a CXC chemokine that is highly expressed in thesecondary lymphoid organs, such as follicles of the spleen, lymph nodes, and Peyer's patches. CXCL13 promotes the migration of B lymphocytes (compared to T cells and macrophages), by stimulating calcium influx into, and chemotaxis of, cells expressing Burkitt's lymphoma receptor 1 (BLR1). BCA1 therefore function in the homing of B lymphocytes to follicles. Human BCA-1 shares a 64% amino acid sequence similarity with the mouse protein and 23 - 34% amino acid sequence identity with other known CXC chemokines. Recombinant or chemically synthesized BCA1 is a potent chemoattractant for B lymphocytes but not T lymphocytes, monocytes or neutrophils. BLR1, a G protein-coupled receptor originally isolated from Burkitt’s lymphoma cells, has now been shown to be the specific receptor for BCA1. Among cells of the hematopoietic lineages, the expression of BLR-1, now designated CXCR-5, is restricted to B lymphocytes and a subpopulation of T helper memory cells.

PFDN4 belongs to the prefoldin beta subunit family. PFDN4 is a heterohexameric chaperone protein that can capture unfolded actin and is a possible transcription factor. Six prefoldin polypeptides, prefoldin 1-6, are known.

Mammalian mitochondrial ribosomal proteins are encoded by nuclear genes and aid in protein synthesis within the mitochondrion. Mitochondrial ribosomes (mitoribosomes) comprised of a small 28S subunit and a large 39S subunit. Among different species, the proteins comprising the mitoribosome vary greatly in sequence, and sometimes in biochemical properties, thus preventing simple recognition by sequence homology. Mitochondrial Ribosomal Protein L2 (MRPL2) is a 39S subunit protein which is a member of the EcoL2 ribosomal protein family.

ARL6 is a member of the ARF family of GTP-binding proteins. ARL6 has a vital part in modulating membrane trafficking and cytoskeletal functions. Mutation in ARL6 is the source of Bardet-Biedl syndrome (BBS3) which is a pleiotropic genetic disorder that causes obesity, photoreceptor degeneration, polydactyly, hypogenitalism, renal abnor-malities and developmental delay.

Cholera Toxin B subunit (ctxB) Cholera is a protein complex secreted by the bacterium Vibrio cholerae. ctxB is responsible for the massive, watery diarrhea characteristic of cholera infection. The cholera toxin is an oligomeric complex made up of 6 protein subunits: a single copy of the A subunit and5 copies of the B subunit, denoted as AB5. Subunit B binds while subunit A activates the G protein which activates adenylate cyclase. The five B subunits form a five-membered ring. The A subunit has 2 important segments. The A1 portion of the chain (CTA1) is a globular enzyme payload that ADP-ribosylates G proteins, while the A2 chain (CTA2) forms an extended alpha helix which sits snugly in the central pore of the B subunit ring.

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.

Fractalkine soluble form is chemotactic for t-cells and monocytes, but not for neutrophils. Fractalkine membrane-bound form promotes adhesion of those leukocytes to endothelial cells. Fractalkine regulates leukocyte adhesion and migration processes at the endothelium and binds to CX3CR1. Natural Human Fractalkine is produced as a long protein (373-amino acid) with an extended mucin-like stalk and a chemokine domain on top. The mucin-like stalk permits it to bind to the cell surface. Fractalkine gene is located on human chromosome 16 along with some CC chemokines known as CCL17 and CCL22.

E3 ubiquitin ligase RNF4 (RNF4) contains a RING finger motif and functions as a transcription regulator. RNF4 interacts with, and inhibits the activity of, TRPS1, a transcription suppressor of GATA-mediated transcription. Transcription repressor ZNF278/PATZ also interacts with the RNF4 protein thus reducing the enhancement of androgen receptor-dependent transcription mediated by RNF4. RNF4 is broadly expressed at low levels in many tissues and highly expressed in the testis.

Spindle And Kinetochore Associated Complex Subunit 1 (SKA1) is a part of the kinetochore-microtubule interface which associates with microtubules as oligomeric assemblies. The complex facilitates the processive movement of microspheres along a microtubule in a depolymerization-coupled manner. SKA1 is necessary for timely anaphase onset during mitosis, when chromosomes undergo bipolar attachment on spindle microtubules leading to silencing of the spindle checkpoint.

PPIases catalyze the cis-trans isomerization of proline imidic peptide bonds in oligopeptides and accelerate the folding of proteins. Cyclophilin-A is a cyclosporin binding-protein and may play a role in cyclosporin A-mediated immunosuppression. Cyclophilin-A can also interact with several HIV proteins, including p55 gag, Vpr, and capsid protein, and has been shown to be necessary for the formation of infectious HIV virions. Multiple pseudogenes that map to different chromosomes have been reported.

Protein A is a cell wall component produced by several strains of Staphylococcus aureus. The recombinant Protein A is genetically engineered protein and holds 5 IgG-binding regions of protein A. Recombinant Protein A functions basically the same as native Protein A and is perfect for purification of polyclonal or monoclonal IgG antibodies. Protein A binds to human IgG1, IgG2 and IgG4, mouse IgG2a, IgG2b and IgG3 and rat IgG2c. Protein A also binds to total IgG from rabbit, pig, dog, cat, and guinea pig.

PFN2 is a ubiquitous actin monomer-binding protein which is part of the profilin family. PFN2 regulates actin polymerization in response to extra cellular signals. PFN2 binds to actin and affects the structure of the cytoskeleton. At high concentrations, profilin prevents the polymerization of actin, while it increases it at low concentrations. PFN2 binds to PIP2, it inhibits the formation of IP3 and DG.

Profilin-1 also known as Pfn1 is a ubiquitous actin monomer-binding protein which is a member of the profilin family. Pfn1 significantly enhances skin wound healing in-vitro as well as in-vivo which is mediated by purinergic receptors. Furthermore, Pfn1 is also active in endothelial cell migration and vessel sprouting. Pfn1 is considered to regulate actin polymerization in response to extracellular signals.

Protein Tyrosine Phosphatase Receptor Type N (PTPRN) is a catalytically inactive protein and a major target of autoimmune response in diabetes mellitus. The long C-terminal intracellular tail covers the majority of autoantibody epitopes. PTPRN is expressed in neural, neuroendocrine and pancreatic islet cells.