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MARCKS-related protein (MARCKSL1) which is a part of MARCKS family of PKC substrate is broadly used in the signal transduction studies as an indicator of PKC activation. MARCKSL1 plays a part in the coordination of membrane-cytoskeletal signaling events, including secretion, migration, phagocytosis and cell adhesion and is expressed in a variety of tissues with highest levels found in testis and uterus. Furthermore, MARCKSL1 serves as a regulator of Integrin activation and is thought to regulate Integrin-dependent signal transduction pathways, particularly those involved in macrophage spreading.

YWHAB belongs to the 14-3-3 family of proteins which are in charge for signal transduction by binding to phosphoserine-containing proteins. YWHAB is found in both plants and mammals. YWHAB protein interacts with RAF1 and CDC25 phosphatases,thus linking mitogenic signaling and the cell cycle machinery. YWHAB is an adapter protein involved in the regulation of a large spectrum of both general and specialized signaling pathway. YWHAB binds to a large number of proteins by recognition of a phosphoserine or phosphothreonine motif. Binding generally results in the modulation of the activity of the binding partner.

HB-EGF is an EGF related growth factor which signals via the EGF receptor, and stimulates the proliferation of SMC (smooth muscle cells), fibroblasts, epithelial cells and keratinocytes. HB-EGF is expressed in various cell types and tissues, including vascular endothelial cells and SMC, macrophages, skeletal muscle, keratinocytes and particular tumor cells. HB-EGF’s ability to explicitly bind HPR sulfate proteoglycans is dissimilar from other EGF-like molecules, and might be related to the enhanced mitogenic activity, relative to EGF, that HB-EGF exerts on smooth muscle cells.

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.

Alpha crystallins are composed of two gene products; alpha-A and alpha-B, for acidic and basic, respectively. Alpha crystallins can be induced by heat shock and are members of the small heat shock protein (sHSP also known as the HSP20). They act as molecular chaperones and hold them in in large soluble aggregates. These heterogeneous aggregates consist of 30-40 subunits; the alpha-A and alpha-B subunits have a 3:1 ratio, respectively. Two additional function of -crystallins are an autokinase activity and participation in the intracellular architecture. Alpha-B is expressed widely in many tissues and organs and occurs in many neurological diseases.

Alpha 1-microglobulin (A1M) is a lipocalin superfamily member (kernal lipocalins). A1M is a low molecular weight protein component of plasma. A1M is distributed in plasma and extravascular compartments of all organs. Alpha-1 Microglobulin is found in mammals, birds, amphibians and fish. The primary sites of A1M synthesis are the liver and the kidney. Around the opening of the lipocalin pocket three lysyl residues are situated; those residues carry yellow-brown modification derived from the binding and degradation of heme and kynurenin (a tryptophan metabolite). A1-Microglobulin’s reductase and dehydrogenase have broad biological substrate specificity properties due to its’ free cysteine side-chain which is located in a flexible loop. Alpha-1-microglobulin is glycosylated by three separate carbohydrate chains: two complex carbohydrates which are N-linked to asparagines at residues 17 and 96, and the other simple carbohydrate which is O-linked to threonine at position 5. The carbohydrates comprise 22% of the total molecular mass of the protein. The glycosylation varies between species. A1M exists in two forms- a free form and complexed to other macromolecules: in humans- complexed to immunoglobulin A (IgA), in rat- complexed to alpha-1-inhibitor-3. Free A1M is exceptionally heterogeneous in charge (therefore also known as protein HC), and is found tightly linked to a chromophore. The free Alpha-1-microglobulin is a monomeric protein composed of one 188 residue polypeptide and contains three cysteines, two of which (residues 75 and 173) form a conserved intra-molecular disulphide link. The chromophoric group is covalently bound to the free cysteine residue at position 34. A1M binds retinol as a major ligand, but this is probably distinct from its covalent chromophore. Half of all human plasma A1M (approximately 0.03mg/ml) forms a 1:1 complex with about 5% of plasma immunoglobulin A. The resulting macromolecular complexes’ molecular weight is 200000, and a plasma concentration of 0.3mg/ml. The complex can exhibit both antibody activity and affect many of the biological actions of free Alpha-1-microglobulin. Alpha-1-microglobulin was first discovered in pathological human urine. It was suggested that A1M might be involved in tissue defense against reactive oxygen species, oxidation by heme and kynurenin. Evidence also suggests that A1M functions in the regulation of the immune system. Other functions include: inhibition of stimulation of cultured lymphocytes by protein antigens; induction of cell division of lymphocytes, a mitogenic effect that can either be enhanced or inhibited by the action of other plasma components; inhibition of neutrophil granulocyte migration in vitro; and inhibition of chemotaxis.
Other functions include inhibition of stimulation of cultured lymphocytes by protein antigens; induction of cell division of lymphocytes, a mitogenic effect that can either be enhanced or inhibited by the action of other plasma components; inhibition of neutrophil granulocyte migration in vitro; and inhibition of chemotaxis.

Vascular endothelial growth factor (VEGF) is an important signaling protein involved in vessel formation As its name implies, VEGF activity has been mostly studied on cells of the vascular endothelium, although it does have effects on a number of other cell types (e.g. stimulation monocyte/macrophage migration, neurons, cancer cells, kidney epithelial cells ). VEGF mediates increased vascular permeability, induces vasculogenesis and endothelial cell production, promotes cell migration, and inhibits apoptosis. In vitro, VEGF has been shown to stimulate endothelial cell mitogenesis and cell migration. VEGF is also a vasodilator and increases microvascular permeability and was originally referred to as vascular permeability factor. VEGF is located in normal cartilage though only osteoarthritic cartilage expresses the VEGF receptors, NP1, VEGFR1 and VEGFR2. The VEGF level in the culture media from OA chondrocytes was more than 3 folds higher than in media from normal chondrocytes

RUNX3 is part of the RUNX family that mediates the expression of genes which participate in cellular differentiation and cell cycle progression. RUNX3 heterodimer and the beta subunit form a complex that binds to the core DNA sequence 5''-PYGPYGGT-3'' found in several enhancers and promoters, and can either activate or suppress transcription. RUNX3 interacts with additional transcription factors. RUNX3 is a good candidate for gastric cancer tumor suppressor diagnosis.

High mobility group protein HMG-I/HMG-Y (HMGA1) belongs to the non-histone chromosomal high mobility group protein (HMG) family. HMGA1 is composed of a highly conserved AT-hook DNA-binding domain which mediates binding to AT-rich sequences in the minor groove of chromosomal DNA. HMGA1 functions as an architectural chromatin-binding transcription factor modifying the conformation of DNA by modulating nuclear protein-DNA complexes. Furthermore, HMGA1 is involved in numerous cellular processes including growth regulation, viral induction of beta-IFN gene and regulation of inducible gene transcription.

BST1 (Bone Marrow Stromal Cell Antigen 1), is a GPI (glycosylphosphatidylinositol) anchored membrane protein which is part of the CD38 family. BST1 was initially recognized as a bone marrow stromal cell molecule. BST1 is an ectoenzyme sharing more than a few features with ADP-ribosyl cyclase CD38. BST1 together with CD38, exhibit both DP-ribosyl cyclase and cyclinc ADP ribose hydrolase activities. BST1 participates in rheumatoid arthritis due to its enhanced expression in RA-derived bone marrow stromal cell lines. Moreover, BST1 is expressed by cells of the myeloid lineage and could perform as a receptor with a signal transduction capability.

Truncated BH3 interacting domain death agonist is a truncated form of the pro-apoptotic full-length BID. Truncated BH3 interacting domain death agonist is generated by Caspase-8 cleavage of BID. The truncated form of the protein translocates from the cytosol to mitochondria and transduces apoptotic signals.
BID is a pro-apoptotic Bcl-2 protein having only the BH3 domain. In reaction to apoptotic signaling, BID interacts with another Bcl-2 family of cell death regulators, called Bax, they form a heterodimer resulting to the insertion of Bax into the outer mitochondrial membrane. Bax induces the opening of the mitochondrial voltage-dependent anion channel which lead to the release of cytochrome c and other pro-apoptotic factors from the mitochondria resulting in activation of caspases. BID is a mediator of mitochondrial damage induced by caspase-8 (CASP8). CASP8 cleaves BID, and the COOH-terminal part translocates to mitochondria where it triggers cytochrome c release. The major proteolytic product p15 BID releasea cytochrome c. Isoform 1, Isoform 2 and Isoform 4 induce ice-like proteases and apoptosis while Isoform 3 does not induce apoptosis.

Four and a half LIM domains 3 (FHL3) belongs to a family of proteins containing a four-and-a-half LIM domain, which is a highly conserved double zinc finger motif. FHL3 has been shown to interact with the cancer developmental regulators SMAD2, SMAD3, and SMAD4, the skeletal muscle myogenesis protein MyoD, and the high-affinity IgE beta chain regulator MZF-1. FHL3 is involved in tumor suppression, repression of MyoD expression, and repression of IgE receptor expression. Two transcript variants encoding different isoforms have been found for this gene.

CCDC101 is known as a subunit of the SAGA (Spt-Ada-Gcn5 acetyltransferase) histone acetyltransferase complex in Saccharomyces cerevisiae. CCDC101 is conserved from yeast to humans.

Mmitochondrial import receptor subunit TOMM20 homolog (TOMM20) is a member of the Tom20 family. The Tom machinery consists of import receptors for the initial binding of cytosolically synthesized preproteins and a general import pore (GIP) for the membrane translocation of various preproteins into the mitochondria. TOMM20 acts as the transit peptide receptor at the surface of the mitochondrion outer membrane and facilitates the movement of preproteins into the TOM40 translocation pore.

TPM1 is a member of the tropomyosin family which consists of a number of extremely conserved, extensively distributed 35-45 kDa actin-binding proteins that are involved in the contractile system of striated and smooth muscles and the cytoskeleton of non-muscle cells. Tropomyosin-1 is composed of 2 alpha-helical chains arranged as a coiled-coil. TPM1 is polymerized end to end alongside the two grooves of actin filaments and provides stability to the filaments. TPM1 binds to actin filaments in muscle and non-muscle cells. TPM1 also functions in association with the troponin complex to regulate the calcium-dependent interaction of actin and myosin during muscle contraction. In non-muscle cells TPM1 is implicated in stabilizing cytoskeleton actin filaments. Smooth muscle contraction is controlled by interaction with caldesmon.
Alternatively spliced transcript variants encoding a range of isoforms have been described in smooth muscle and non-muscle cells. TPM1 Isoform 1 is expressed in adult and fetal skeletal muscle and cardiac tissues, with higher expression levels in the cardiac tissues, whereas Isoform 10 is expressed in adult and fetal cardiac tissues, but not in skeletal muscle.
Mutations in the TPM1 gene are linked to type 3 familial hypertrophic cardiomyopathy.

Ganglioside GM2 activator (GM2A) is a small glycolipid transport protein which functions as a substrate specific co-factor for the lysosomal enzyme beta-hexosaminidase A. GM2A participates in lipid metabolism. GM2A protein is localized in lysosomes. The GM2A protein forms a large binding pocket for a number of single chain phospholipids and fatty acids. GM2A demonstrates calcium-independent phospholipase activity. GM2A stimulates ganglioside GM2 degradation by presenting GM2 to beta-hexosaminidase A. The Beta-hexosaminidase A, along with GM2A, catalyzes the degradation of the ganglioside GM2, and other molecules containing terminal N-acetyl hexosamines. GM2A gene mutations result in GM2-gangliosidosis type AB or the AB variant of Tay-Sachs disease.

GNB2L1 was first known as an anchoring protein for protein kinase C beta (PKCbeta), which it stabilizes in the active state and anchors to membranes or functional sites. But, there is now confirmation that GNB2L1 has an essential part of in critical biological responses. GNB2L1 binds specifically to the active form of PKCbeta isoforms and cooperates with numerous other vital signaling proteins such as the androgen receptor, the Src kinase family, integrin beta1, integrin beta2, integrin beta3 and integrin beta5, beta-spectrin and dynamin, RasGAP, IGF-1r, Epstein-Barr virus trans-activator protein BZLF1, p73 and pRB. GNB2L1 is highly expressed in tissues of higher mammals and humans including spleen, liver and brain.

PRRX1 is part of the paired family of homeobox proteins. PRRX1 functions as a transcription co-activator, enhancing the DNA-binding activity of serum response factor, a protein required for the induction of genes by growth and differentiation factors. PRRX1 also regulates muscle creatine kinase, and therefore has a part in the establishment of diverse mesodermal muscle types. The protein binds to an A/T-rich element in the muscle creatine enhancer. Among the diseases associated with PRRX1 are agnathia-otocephaly complex, and pleomorphic liposarcoma.

Alpha 1 ACT is an early-stage acute-phase plasma protein and a serpin that preferentially inactivates chymotrypsin, cathepsin G, and chymase. Alpha-1- ACT, a serine protease inhibitor, is tightly associated with amyloid plaques in Alzheimer's disease (AD) and in normal aged human and monkey brain.
Regulation of the serine proteases and serine protease inhibitors plays an important role in neuromuscular differentiation. Prostate specific antigen (PSA), a chymotrypsin-like serine protease, is predominantly complexed to Alpha-1-ACT.

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.

S100A6 is a member of the S100 family of proteins containing 2 EF-hand calcium-binding motifs. S100 proteins are localized either in the cytoplasm or the nucleus of a wide range of cells. S100 proteins are involved in the regulation of a number of cellular processes such as cell cycle progression and differentiation. There are at least 13 members in the S100 gene family, which are located as a cluster on chromosome 1q21.
S100A6 may function in stimulation prolactin secretion, and exocytosis. Chromosomal rearrangements and altered expression of the S100A6 gene are implicated in melanoma.

Mitochondrial Ribosomal Protein L48, also known as MRPL48, is a mammalian mitochondrial ribosomal protein which assists in protein synthesis within the mitochondrion. Mitochondrial ribosomes, mitoribosomes, consist of a small 28S subunit and a large 39S subunit. They include an estimated 75% protein to rRNA composition while comparing to prokaryotic ribosomes, where this ratio is reversed.An additional dissimilarity between mammalian mitoribosomes & prokaryotic ribosomes is that the latter contain a 5S rRNA. Between different species, the proteins containing the mitoribosome differ very much in sequence, as well as in biochemical properties from time to time, which prevents easy recognition through sequence homology. MRPL48 encodes a 39S subunit protein. A pseudogene corresponding to MRPL48 is found on chromosome 6p.

SCO Cytochrome Oxidase Deficient Homolog 1, also known as SCO1 is a member of the SCO1/2 family. Mammalian cytochrome c oxidase (COX) catalyzes the transfer of reducing equivalents from cytochrome c to molecular oxygen and pumps protons across the inner mitochondrial membrane. Furthermore, in yeast, two related COX assembly genes, SCO1 & SCO2 which are synthesis of cytochrome c oxidase, enable subunits 1 as well as 2 to be incorporated into the holoprotein. This gene is the human homolog to the yeast SCO1 gene. Among the diseases associated with SCO1 are hepatic failure, early-onset, neurologic disorder due to cytochrome c oxidase deficiency and fatal infantile cytochrome c oxidase deficiency.

E-selectin (SELE) is a part of a family of divalent cation-dependent carbohydrate-binding glycoproteins or adhesion molecules. E-selectin is expressed on the surface of endothelial cells and mediates the interaction of leukocytes and platelets with endothelial cells during an inflammatory response. E-selectin is present in single copy in the human genome and contains 14 exons spanning about 13 kb of DNA.