Search results

Retinoblastoma (RB) is an embryonic malignant neoplasm of retinal origin. It almost always presents in early childhood and is often bilateral. Spontaneous regression ('cure') occurs in some cases. Retinoblastoma acts as a regulator of other genes and forms a complex with adenovirus e1a and with sv40 large t antigen. Retinoblastoma acts as a tumor suppressor and modulats functionally certain cellular proteins with which t and e1a compete for pocket binding. Retinoblastoma is potent inhibitor of e2f-mediated trans-activation, recruits and targets histone methyltransferase suv39h1 leading to epigenetic transcriptional repression, inhibits the intrinsic kinase activity of taf1.

RBBP9, restricts to the nucleus and cytoplasm, is a retinoblastoma binding protein which takes part in the regulation of cell proliferation and differentiation. RBBP9 cooperates with retinoblastoma (Rb) and offers cellular resistance to the growth-inhibitory effects of TGFbeta1, therefore enabling the cellular transformation process.

Retinoblastoma binding protein 4 (RBBP4) is a ubiquitously expressed nuclear protein which is a member of a highly conserved subfamily of WD-repeat proteins. RBBP4 is present in protein complexes involved in histone acetylation and chromatin assembly. In addition, RBBP4 is part of co-repressor complexes, which is a fundamental component of transcriptional silencing. RBBP4 is observed among several cellular proteins which bind directly to a retinoblastoma protein to regulate cell proliferation. RBBP4 also is a part of the Mi-2 complex which is implicated in chromatin remodeling and transcriptional repression connected with histone deacetylation.

Recoverin is a member of the recoverin family of neuronal calcium sensors. Recoverin is a heterogeneously acylated calcium-binding and intracellular signal transduction 23kDa protein in the photoreceptor cells of retina. Recoverin contains four EF-hands, of which two bind Ca. Ca-induced extrusion of the acyl group from a hydrophobic cleft in the protein drives the translocation of recoverin from solution to the disc membrane. Recoverin may prolong the termination of the phototransduction cascade in the retina by blocking the phosphorylation of photo-activated rhodopsin. Recoverin plays a key role in the inhibition of rhodopsin kinase, a molecule that regulates the phosphorylation of rhodopsin. This in due course controls the ability of the eye to adapt to, and recover from, exposure to the presence of light. Recoverin is a detectable serologic protein that is expressed in patients with cancer-associated retinopathy, a paraneoplastic syndrome.

Recoverin is a member of the recoverin family of neuronal calcium sensors. Recoverin is a heterogeneously acylated calcium-binding and intracellular signal transduction 23kDa protein in the photoreceptor cells of retina. Recoverin contains four EF-hands, of which two bind Ca. Ca-induced extrusion of the acyl group from a hydrophobic cleft in the protein drives the translocation of recoverin from solution to the disc membrane. Recoverin may prolong the termination of the phototransduction cascade in the retina by blocking the phosphorylation of photo-activated rhodopsin. Recoverin plays a key role in the inhibition of rhodopsin kinase, a molecule that regulates the phosphorylation of rhodopsin. This in due course controls the ability of the eye to adapt to, and recover from, exposure to the presence of light. Recoverin is a detectable serologic protein that is expressed in patients with cancer-associated retinopathy, a paraneoplastic syndrome.

The somatomedins, or insulin-like growth factors (IGFs), comprise a family of peptides that play important roles in mammalian growth and development. IGF1 mediates many of the growth-promoting effects of growth hormone (GH; MIM 139250). Early studies showed that growth hormone did not directly stimulate the incorporation of sulfate into cartilage, but rather acted through a serum factor, termed 'sulfation factor,' which later became known as 'somatomedin' (Daughaday et al., 1972). Three main somatomedins have been characterized: somatomedin C (IGF1), somatomedin A (IGF2; MIM 147470), and somatomedin B (MIM 193190) (Rotwein, 1986; Rosenfeld, 2003).

Ras-related protein Ral-B (RALB) is a member of a subfamily of Ras-related GTPases. RALB is activated by a unique nucleotide exchange factor, Ral GDS, and deactivated by a distinct GTPase-activating protein. RALB has a role in the late stages of cytokinesis and is required for the abscission of the bridge joining the sister cells emerging from mitosis. In addition, RALB is required for suppression of apoptosis.

RARRES2 is a secreted chemotactic protein that initiates chemotaxis through the ChemR23 G protein-coupled seven-transmembrane domain ligand. RARRES2 is upregulated by the synthetic retinoid tazarotene and found in a vast variety of tissues. RARRES2 acts as an adipokine, and is truncated on both termini from the proprotein. RARRES2 is structurally related to the cathelicidin precursors, cystatin C and kininogens. RARRES2 promotes calcium mobilization and chemotaxis of immature dendritic cells and macrophages. RARRES2 is secreted as a precursor of little biological activity, which requires proteolytic cleavage of its COOH-terminal domain to be exchangeed into a potent and highly specific agonist of ChemR23. RARRES2 signals via its receptor, ChemR23 (CMKLR1), as a positive regulator of adipocyte differentiation and metabolic function. The Chemerin receptor acts as a coreceptor for SIV and some primary HIV-1 strains. The Chemerin receptor has another ligand, called tazarotene-induced gene.

The retinoid X receptor (RXR) is a pleiotropic nuclear receptor transcription factor that interacts with a variety of nuclear receptor dimeric partner. RXR binds cognate response elements as a homodimer in the presence of its ligand, 9-cis retinoic acid, or as a heterodimer with other members of the nuclear hormone receptor superfamily including retinoic acid receptors (RAR), thyroid hormone receptors (TR), vitamin D receptors and peroxisome proliferators-activated receptors (PPAR). The RXR family includes three different isoforms; RXR a, b, g . Human RXR a gene is localized on 9q34.9 and encodes two major isoforms (RXR a1, RXR a2). The DNA binding domain of RXR (111-228aa) was purified by using conventional column chromatography techniques.

Bestrophin 1 (BEST1) is a part of the bestrophin gene family and is also forms calcium-activated chloride-ion channels in epithelial. This small gene family is characterized by proteins with a highly conserved N-terminus with 4-6 transmembrane domains. BEST1 is extremely permeable to bicarbonate.

RAB27A is part of the small GTPase superfamily, Rab family. RAB27A is membrane-bound and participates in protein transport and small GTPase mediated signal transduction. Mutations in this RAB27A are associated with Griscelli syndrome type 2. RAB27A is involved in cytotoxic granule exocytosis in lymphocytes.RAB27A is necessary for both granule maturation and granule docking and priming at the immunologic synapse.

Retinoic acid receptor alpha (RAR) belongs to the large family of ligand responsive gene regulatory proteins that includes receptors for steroid and thyroid hormones. These proteins contain two highly conserved domains that are involved in determining their DNA and ligand-binding activities. There are three isotypes of RAR proteins: alpha, beta, and gamma. The RAR proteins are encoded by distinct genetic loci and possess distinct transcriptional properties. Typically, RAR-alpha represses target gene transcription in the absence of hormone, whereas RAR-beta and gamma fail to repress under these conditions. RARA is a receptor for retinoic acid that has profound effects on vertebrate development. Retinoic acid is a morphogen and is a powerful teratogen. RARA controls cell function by directly regulating gene expression.
Chromosomal aberrations involving RARA cause acute promyelocytic leukemia (APL).

Ras-related protein Ral-A (RALA) is a member of the small GTPase superfamily, Ras family of proteins. RALA mediates a distinct downstream signaling pathway from Ras which facilitates cellular transformation. Furthermore, RALA is thought to be involved in various signaling cascades, including regulation of the cytoskeleton, vesicle trafficking, and endocytosis.

Retinoic Acid Receptor Responder 1 (RARRES1) is a part of the TIGs family. TIGs operate like tumor suppressor genes in human cancers and are greatly expressed in skin, hair follicles and endothelial cells plus in pancreas, spleen and intestine. TIGs are growth regulators which mediate the growth suppressive effects of retinoids.

Ras-related protein Ral-A (RALA) is a member of the small GTPase superfamily, Ras family of proteins. RALA mediates a distinct downstream signaling pathway from Ras which facilitates cellular transformation. Furthermore, RALA is thought to be involved in various signaling cascades, including regulation of the cytoskeleton, vesicle trafficking, and endocytosis.

Neuroblastoma suppressor of tumorigenicity 1 (NBL1) is a part of the evolutionarily conserved CAN (Cerberus and DAN) family of proteins, which contain a domain resembling the CTCK (C-terminal cystine knot-like) motif found in several signaling molecules. NBL1 is a is a tumor suppressor of neuroblastoma and takes part in preventing cells from entering the final stage (G1/S) of the transformation process. NBL1 is produced in small neurons of the dorsal root ganglion. The expression of NBL1 is triggered by MATH-1.

RAB, Member RAS Oncogene Family-Like 5 (RABL5) belongs to the Ras superfamily of small GTP-binding proteins. The Ras-related superfamily of guanine nucleotide binding proteins includes the R-Ras, Rap, Ral/Rec and Rho/Rab subfamilies. Rab proteins have an essential role in endocytosis or in biosynthetic protein transport. The transporting process of newly synthesized proteins from the endoplasmic reticulum to various stacks of the Golgi complex and to secretory vesicles includes the movement of carrier vesicles and requires Rab protein function.

RARRES2 is a secreted chemotactic protein that initiates chemotaxis through the ChemR23 G protein-coupled seven-transmembrane domain ligand. RARRES2 acts as an adipokine, and is truncated on both termini from the proprotein. RARRES2 is structurally related to the cathelicidin precursors, cystatin C and kininogens. RARRES2 promotes calcium mobilization and chemotaxis of immature dendritic cells and macrophages. RARRES2 is secreted as a precursor of little biological activity, which requires proteolytic cleavage of its COOH-terminal domain to be exchangeed into a potent and highly specific agonist of ChemR23. RARRES2 signals via its receptor, ChemR23 (CMKLR1), as a positive regulator of adipocyte differentiation and metabolic function. The Chemerin receptor acts as a coreceptor for SIV and some primary HIV-1 strains.

RELM-beta (Resistin-Like Molecule-beta) is a member of a recently identified family of secreted proteins containing a conserved cystein-rich C-terminus. The RELM family consists of resistin (also called FIZZ3), RELM-alfa (FIZZ1), RELM-beta (FIZZ2) and RELM-gamma. Only resisistin and RELM-beta were found in humans whereas all four RELM family members were identified in rodents.
RELM-beta appears to be produced as a homodimer exclusively by intestinal goblet cells and can be found in high quantities in stool. Remarkably, stool of germ-free mice displaying sterile intestinal tract does not contain RELM-beta until bacterial colonization takes place after pathogen-free mice entered natural environment. Some, but not all, colon carcinoma cell lines secrete RELM-beta into the cell culture supernatant.
The physiological function of RELM-beta is not known. High doses of recombinant RELM-beta showed hyperglycemic effects including lowered glucose disposal and increased hepatic glucose production in mice.

NRAS binds GDP/GTP and has intrinsic GTPase activity. NRAS is a membrane protein that shuttles between the Golgi apparatus and the plasma membrane. This transport is regulated through palmitoylation and depalmitoylation by the ZDHHC9-GOLGA7 complex. NRAS is activated to a GTP-bound form by a GTPase activating protein and inactivated to a GDP-bound form by a guanine nucleotide-exchange factor. Defects in this NRAS gene result in juvenile myelomonocytic leukemia.

RLBP1 is a 36-kD water-soluble protein that transports 11-cis-retinal or 11-cis-retinaldehyde as physiologic ligands. RLBP1 is a functional element of the visual cycle. RLBP1 gene mutations cause retinitis punctata albescens, severe rod-cone dystrophy and Bothnia dystrophy (nonsyndromic autosomal recessive retinitis pigmentosa).

RARRES2 is a secreted chemotactic protein that initiates chemotaxis through the ChemR23 G protein-coupled seven-transmembrane domain ligand. RARRES2 is upregulated by the synthetic retinoid tazarotene and found in many tissues. RARRES2 acts as an adipokine and is truncated on both termini from the proprotein. RARRES2 is structurally related to the cathelicidin precursors, cystatin C and kininogens. RARRES2 promotes calcium mobilization and chemotaxis of immature dendritic cells and macrophages. RARRES2 is secreted as a precursor of little biological activity, which requires proteolytic cleavage of its COOH-terminal domain to be exchangeed into a potent and highly specific agonist of ChemR23.

RAET1L plays a role as a stress-induced ligand for NKG2D receptor. Retinoic Acid Early Transcript 1L (RAET1L) is linked to the cell membrane by the GPI anchor. HCMV infection triggers RAET1L’sexpression but HCMV alters its function. HCMV-encoded UL16 glycoprotein retains RAET1L/ULBP6 inside the cells, preventing it from reaching the cell surface and being exposed to cells of the immune system. RAET1L has a more restricted expression profile in cell lines and primary human tissues than other NKG2D ligands.