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Ras-related GTP binding C (RRAGC) is a monomeric guanine nucleotide-binding protein, or G protein. As a result of binding GTP or GDP, small G proteins act as molecular regulators in various cell processes and signaling pathways. RRAGC regulates the organization of the actin cytoskeleton and has an intrinsic GTPase activity. RRAGC is possibly necessary for the amino acid-induced relocalization of mTORC1 to the lysosomes and its succeeding activation by the GTPase RHEB, which is key step in the activation of the TOR signaling cascade by amino acids.

RAC2 is a small signaling G protein/GTPase which is part of the RAS superfamily of small GTP-binding proteins which regulate cell growth, actin cytoskeletal organization, cell proliferation, survival, cell cycle progression, gene transcription rgulation and the activation of protein kinases. RAC2 cycles between an active gtp-bound and inactive gdp-bound state. In active state, RAC2 binds to a variety of effector proteins to regulate cellular responses, such as secretory processes, phagocytose of apoptotic cells and epithelial cell polarization. RAC2 is involved in the regulation of the nadph oxidase.

RAC3 belongs to the Rac subfamily of the Rho small G proteins. RAC3 is a small (approximately 21kDa) monomeric GTP-binding protein, which is an important component of intracellular signaling pathway, including the control of cell growth, cytoskeletal reorganization, and the activation of protein kinases.

GADD45GIP1 is a nuclear protein which takes part in apoptosis control. GADD45GIP1 is expressed in several tissues, such as heart, thyroid, trachea, kidney, ovary, pancreas, testis and stomach and acts as a negative regulator of G1 to S phase cell cycle production by collaborating with GADD45 proteins to inhibit the activity of cyclin-dependent kinases.

PDE6H belongs to the rod/cone cGMP-PDE gamma subunit family, which selectively catalyze the hydrolysis of 3 cyclic phosphate bonds in adenosine and/or guanine 3,5 cyclic monophosphate (cAMP and/or cGMP). This family regulates the cellular levels, localization and duration of action of these second messengers by controlling the rate of their degradation. PDE6H is the inhibitory (or gamma) subunit of the cone-specific cGMP phosphodiesterase, which is atetramer composed of two catalytic chains (alpha and beta), and two inhibitory chains (gamma). PDE6H is particularly expressed in the retina, and is implicated in the transmission and amplification of the visual signal. Mutations in PDE6H have been associated with retinal cone dystrophy type 3A.

RAB3A Interacting Protein Like 1 (RAB3IL1) is a 382 amino acid protein which is a member of the SEC2 family. RAB3IL1 is a guanine nucleotide exchange factor (GEF) for Rab3A. RAB3IL1 competes for interaction with Rab3A and IHPK1 via its coiled coil domain, which doesn’t involve IHPK1 kinase activity.

RGS19 is a member of RGS (regulator of G protein signaling) family and negatively regulates G protein coupled receptor signaling. RGS19 protein specifically cooperates with heterotrimeric GTP-binding protein G alpha i3 (GAI3).

RGS2 belongs to the RGS family which are regulatory molecules that act as GTPase activating proteins for G alpha subunits of heterotrimeric G proteins. RGS2 inhibits signal transduction by increasing the GTPase activity of G protein alpha subunits and as a result driving them into their inactive GDP-bound form.

Inhibitor of Growth Family Member 1, also known as ING1 is a tumor suppressor protein which is able to induce cell growth arrest and apoptosis. ING1 is a nuclear protein which physically act together with the tumor suppressor protein TP53 and is a component of the p53 signaling pathway. In addition, Reduced expression and rearrangement of ING1 have been identified in various cancers. Multiple alternatively spliced transcript variants encoding distinct isoforms have been described for ING1.

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.

SBDS is part of an extremely preserved protein family which exists from archaea to vertebrates and plants. SBDS protein functions in RNA metabolism and has a role in the biogenesis of the 60S ribosomal subunit and translational activation of ribosomes. Shwachman-Diamond syndrome is a rare autosomal recessive disorder produced by mutations in the SBDS gene.

ADP-ribosylation factor-like 14 (ARL14) is a developmentally regulated member of the ADP-ribosylation factor/ARF-like protein (ARF/ARL) family of Ras-related GTPases. ARL14 is GTPase which recruits MYO1E to MHC class II-containing vesicles via the effector protein C11orf46/ARF7EP and thus controls the movement of these vesicles along the actin cytoskeleton in dendritic cells. MHC-II transport was controlled by the GTPase ARL14/ARF7, which recruits the motor myosin 1E via an effector protein ARF7EP.

ROBLD3 is a member of the GAMAD family. ROBLD3 is an adapter protein which enhances the efficiency of the MAP kinase cascade and facilitates the activation of MAPK2. ROBLD3 compels the recruitment of MP1 to late endosomes where they form a very stable heterodimeric complex required for ERK activation on endosomes. In humans, a mutation in the ROBLD3 gene has been associated with a primary immunodeficiency syndrome, and suggests a role for the ROBLD3 protein in endosomal biogenesis.

Regulation Of Nuclear Pre-MRNA Domain Containing 1A (RPRD1A) is upregulated in cells overexpressing cyclin-dependent kinase inhibitor p15(INK4b) and may have a part in cell cycle regulation. RPRD1A interacts with phosphorylated C-terminal heptapeptide repeat domain (CTD) of the largest RNA polymerase II subunit POLR2A, and partakes in dephosphorylation of the CTD. RPRD1A May function as a negative regulator of cyclin-D1 (CCND1) and cyclin-E (CCNE1) in the cell cycle.

Regulator of G protein signaling 4 (RGS4) is a protein which regulates G protein signaling. Regulator of G protein signaling (RGS) family members are regulatory molecules which act as GTPase activating proteins (GAPs) for G alpha subunits of heterotrimeric G proteins. Heterotrimeric G proteins serve to convey information from cell surface receptors to intracellular effectors.

Peptidase Inhibitor 3, also referred to PI3, is neutrophil and pancreatic elastase-specific inhibitor of skin. The protein may prevent elastase mediated tissue proteolysis. PI3 has shown inhibition of alpha-4-beta-2/CHRNA2-CHRNB2 nicotinic acetylcholine receptor, a weak inhibition on Kv11.1/KCNH2/ERG1 and on the transient receptor potential cation channel subfamily V member 1.

Suppressor of Cytokine Signaling 3, also known as SOCS3 belongs to the SOCS family; in addition SOCS3 is a member of the STAT-induced STAT inhibitor (SSI). The SSI family members are cytokine-inducible negative regulators of cytokine signaling. The expression of SOCS3 is induced by different cytokines, including IL6 and IL10. SOCS3 can bind to JAK2 kinase, and inhibit the activity of JAK2 kinase. Studies of the mouse counterpart of SOCS3 have shown the roles of SOCS3 in the negative regulation of fetal liver hematopoiesis, and placental development.

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.

Discoidin Domain Receptor Tyrosine Kinase 1 (DDR1) is a transmembrane glycoprotein which is a part of the discoidin-like domain containing subfamily of receptor tyrosine kinases. DDR1 functions as cell surface receptor for fibrillar collagen and regulates cell attachment to the extracellular matrix, remodeling of the extracellular matrix, cell migration, differentiation, survival and cell proliferation. DDR1 is expressed in epithelial cells, mainly in the kidney, lung, gastrointestinal tract, and brain and is significantly overexpressed in several human tumors.

Cyclin-dependent kinase inhibitors (CDKIs) are proteins that bind to and inhibit the activity of CDKs. Two major classes of CDK inhibitors have been identified. The p16 family (p15, p16, p18 and p19) binds to and inhibits the activities of CDK4 and CDK6. The p21 family (p21, p27, p28 and p57) can bind to broad range of CDK-cyclin complexes and inhibit their activities. CDKIs are capable of suppressing growth, and several lines of evidence strongly suggest that at least some CDKIs may be tumor suppressor proteins.

Trypsin inhibitor SPINK1 is secreted from pancreatic acinar cells into pancreatic fluid. SPINK1 has a role in inhibition of trypsin-catalyzed premature initiation of zymogens in the pancreas and the pancreatic duct. Alterations in SPINK1 gene are the cause for tropical calcific and pancreatitis hereditary pancreatitis.

Gankyrin (proteasome 26S subunit) is a multicatalytic proteinase oncoprotein commonly overexpressed in most hepatocellular carcinomas. Proteasomes are found throughout eukaryotic cells at a high concentrations and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. Gankyrin interacts with S6 ATPase of the 19S regulatory particle of the 26S proteasome. Gankyrin is involved in theregulation of the phosphorylation of the retinoblastoma protein by CDK4, and to enhance the ubiquitinylation of p53 by MDM2. Gankyrin consists of 7 ankyrin repeats and is structurally similar to I kappa Bs. Gankyrin acts as a regulatory subunit of the 26s proteasome which is involved in the atp-dependent degradation of ubiquitinated proteins. Gankyrin is involved in progression of esophageal squamous cell carcinoma. gankyrin plays an oncogenic role especially in early stages of human epatocarcinogenesis. Gankyrin binds to NF-kappaB and suppresses its activity at the transcription level by modulating acetylation through SIRT1. Structural comparison between Gankyrin & p16(INK4A) identified numerous residues of gankyrin that are potentially important for CDK4 binding.

PDIA3 is an enzyme that belongs to the endoplasmic reticulum and interacts with lectin chaperones calreticulin and calnexin to modulate folding of newly synthesized glycoproteins. PDIA3 has protein disulfide isomerase activity. Complexes of lectins and PDIA3 mediate protein folding by promoting formation of disulfide bonds in their glycoprotein substrates. PDIA3 is expressed in the lumbar spinal cord from rats submitted to peripheral lesion during neonatal period. PDIA3 interacts with thiazide-sensitive sodium-chloride cotransporter in the kidney and is induced by glucose deprivation. PDIA3 is part of the major histocompatibility complex (MHC) class I peptide-loading complex (TAP1), which is important for formation of the final antigen conformation and export from the endoplasmic reticulum to the cell surface.