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Protein Phosphatase 1, Regulatory Subunit 3B (PPP1R3B) is the catalytic subunit of the serine/theonine phosphatase, protein phosphatase-1. PPP1R3B, which is expressed both in liver and in skeletal muscle tissue, regulates glycogen synthesis in these tissues. PPP1R3B is involved in type 2 diabetes and maturity-onset diabetes of the young.

MYL9 is one of the numerous regulatory myosin light chains. Myosin which is a structural component of the muscle consists of 2 heavy chains and 4 light chains. MYL9 is a myosin light chain regulates muscle contraction by modulating the ATPase activity of myosin heads. MYL9 binds calcium and is activated by myosin light chain kinase. Regulatory myosin light chains regulate contraction in smooth muscle and non-muscle cells via phosphorylation by MLCK (myosin light chain kinase). Phosphorylation of regulatory myosin light chains is catalyzed by MLCK in the presence of calcium and calmodulin and it increases the actin-activated myosin ATPase activity, thus regulates the contractile activity.

43 kDa receptor-associated protein of the synapse (RAPSN), is expressed in the postsynaptic membrane of skeletal muscle. RAPSN is essential for the clustering of nicotinic acetylcholine receptors (nAChR). In addition RAPSN self-associates via at least two of its seven tetra-tricopeptide repeats (TPRs). RAPSN interacts with the large intracellular domain of the nAChR a subunit all the way through the hydrophobic surface of the coiled-coil domain. RAPSN modifies trafficking of AChR within the cell. Overexpression inhibits agrin-induced AChR clustering pathway. RAPSN also plays a role in postsynaptic congenital myasthenic syndromes.

Protein phosphatase 1 regulatory subunit 11 (PPP1R11) is located within the major histocompatibility complex class I region on chromosome 6 and is expressed in a variety of both adult and embryonic tissues. PPP1R11 acts as an inhibitor of PP1 (protein phosphatase 1), particularly showing a sensitivity toward the metal-independent and metal-dependent forms of PP1. Deletion of a portion of the q arm of chromosome 6 is related with early onset intestinal cancer, proposing the presence of a cancer vulnerability locus.

NAD (P) Dependent Steroid Dehydrogenase-Like (NSDHL) takes part in synthesis of cholesterol. NSDHL is involved in one of a few steps which convert lanosterol to cholesterol by removing a carbon atom and three hydrogen atoms (a methyl group). NSDHL is also a vital element of cell membranes and myelin, the fatty covering that insulates nerve cells.

Akt1, also known as Akt or else protein kinase B (PKB) is an important molecule in mammaliancellular signaling. In humans, there are three genes in the "Akt family": Akt1, Akt2, and Akt3. Moreover, these enzymes are members of the serine/threonine-specific protein kinase family (EC2.7.11.1). Akt1 is involved in cellular survival pathways, by inhibiting apoptoticprocesses. Akt1 is also able to induce protein synthesis pathways, and is therefore a key signaling protein in the cellular pathways which lead to skeletal muscle hypertrophy, and general tissue growth. Since it can block apoptosis, and thereby promote cell survival, Akt1 has been implicated as a most important factor in numerous types of cancer. Akt (now also called Akt1) was at first identified as the oncogenein the transforming retrovirus, AKT8.

MAPK14 belongs to the MAP kinase family and is most associated with p38 MAP kinases(MAPKs). MAPKs are activated mainly as a reaction to cellular stress and inflammatory cytokines, and inhibitors that target the MAPK14 and MAPK11 have demonstrated ability to cure inflammatory disease. The substrates of this kinase contain transcription regulator ATF2, MEF2C, and MAX, cell cycle regulator CDC25B, and tumor suppressor p53, which demonstrate the parts of MAPK14 in stress-related transcription, cell cycle regulation and genotoxic stress response.

C3 is central to the activation of all 3 pathways of complement activation. Initiation of each pathway generates proteolytic enzyme complexes which binds the target surface. These enzymes cleave a peptide bond in C3 releasing the anaphylatoxin C3a and activating C3b. Most of the C3 activated during complement activation never attaches to the surface due to its thioester reaction with water forming fluid phase C3b which is rapidly inactivated by factors H and I forming iC3b. Surface-bound C3b is necessary in all 3 pathways for efficient activation of C5 and formation of C5b-9 complexes that lyse the target cell membrane.

C3 is central to the activation of all 3 pathways of complement activation. Initiation of each pathway generates proteolytic enzyme complexes which binds the target surface. These enzymes cleave a peptide bond in C3 releasing the anaphylatoxin C3a and activating C3b. Most of the C3 activated during complement activation never attaches to the surface due to its thioester reaction with water forming fluid phase C3b which is rapidly inactivated by factors H and I forming iC3b. Surface-bound C3b is necessary in all 3 pathways for efficient activation of C5 and formation of C5b-9 complexes that lyse the target cell membrane.

The Regulatory (R) subunit of Protein Kinase A (PKA) inhibits its kinase activity by shielding the Catalytic (C) subunit from physiological substrates. This inhibition is reversed in response to extra-cellular signals that increase cAMP levels in the cytoplasm. Upon cAMP binding to R, C is allosterically released from R, activating a spectrum of downstream signaling cascades. Crystallographic data indicated that a series of distinct conformational changes within CBD-A must occur to relay the cAMP signal from the cAMP binding site to the R:C interaction interface. One critical cAMP relay site within the CBD-A of R has been identified as Asp170 because the D170A mutation selectively reduces the negative cooperativity between the cAMP- and C-recognition sites (i.e. the KD for the R:C complex in the presence of cAMP is reduced by more than 12-fold), without significantly compromising the high affinity of R for both binding partners.

Phospholysine phosphohistidine inorganic pyrophosphate phosphatase (LHPP) belongs to the HAD-like hydrolase superfamily. LHPP is an exceptional enzyme which hydrolyzes not only oxygen-phosphorus bonds in inorganic pyrophosphate but also nitrogen-phosphorus bonds in phospholysine, phosphohistidine and imidodiphosphate in vitro. LHPP is expressed in the liver, kidney and moderately in the brain.

GREM1 belongs to the BMP (bone morphogenic protein) antagonist family. Like BMPs, BMP antagonists comprise cystine knots and usually form homo- and heterodimers. The CAN (cerberus and dan) subfamily of BMP antagonists, to which GREM1 belongs, is characterized by a C-terminal cystine knot with an eight-membered ring. The antagonistic effect of the secreted glycosylated protein is because of its direct binding to BMP proteins. As an antagonist of BMP, GREM1 takes a place in regulating organogenesis, body patterning, and tissue differentiation. In mouse, GREM1 has been shown to convey the sonic hedgehog (SHH) signal from the polarizing region to the apical ectodermal ridge during limb bud outgrowth. Alternatively merged transcript variants encoding different isoforms have been found for this gene.

Parathyroid hormone (PTH), or parathormone, is secreted by the parathyroid glands as a polypeptide containing 84 amino acids. It acts to increase the concentration of calcium in the blood, whereas calcitonin (a hormone produced by the parafollicular cells of the thyroid gland) acts to decrease calcium concentration. PTH acts to increase the concentration of calcium in the blood by acting upon parathyroid hormone receptor in three parts of the body: In the bones- It enhances the release of calcium from the large reservoir contained in the bones. Bone resorption is the normal destruction of bone by osteoclasts, which are indirectly stimulated by PTH. Stimulation is indirect since osteoclasts do not have a receptor for PTH; rather, PTH binds to osteoblasts, the cells responsible for creating bone. Binding stimulates osteoblasts to increase their expression of RANKL, which can bind to osteoclast precursors containing RANK, a receptor for RANKL. The binding of RANKL to RANK stimulates these precursors to fuse, forming new osteoclasts which ultimately enhances the resorption of bone. In the kidney- It enhances active reabsorption of calcium from distal tubules and the thick ascending limb. In the intestine- It enhances the absorption of calcium in the intestine by increasing the production of vitamin D and upregulating the enzyme responsible for 1-alpha hydroxylation of 25-hydroxy vitamin D, converting vitamin D to its active form (1,25-dihydroxy vitamin D) which effects the actual absorption of calcium (as Ca2+ ions) by the intestine via calbindin.

The human cytomegalovirus UL99-encoded pp28 is a myristylated phosphoprotein that is a constituent of the virion. The pp28 protein is positioned within the tegument of the virus particle, a protein structure that resides between the capsid and envelope. In the infected cell, pp28 is found in a cytoplasmic compartment derived from the Golgi apparatus, where the virus buds into vesicles to acquire its final membrane.

p59-Fyn is a member of the protein-tyrosine kinase oncogene family. p59fyn is a membrane-associated non-receptor protein tyrosine kinase that belongs to the Src-family of kinases. p59-Fyn encodes a membrane-associated tyrosine kinase which is implicated in the control of cell growth. p59-Fyn associates with the p85 subunit of phosphatidylinositol 3-kinase and interacts with the fyn-binding protein. The unique N-terminal domain of p59fyn interacts with the CD3 and eta chains of the TcR. p59fyn can bind other proteins (p82 and p116) through its SH2 and SH3 domains, which may act as substrates or regulators of fyn activity. p59fyn is highly expressed in brain suggesting that it may have a role in the sensory nervous network and in myelination at early stages of CNS formation. Distinct isoforms exist due to alternative splicing.

RHOQ (rho-related GTP-binding protein RhoQ) is a small signaling G protein which cycles between an active GTP-bound and an inactive GDP-bound state. In the active state it binds to a diversity of effector proteins to regulate cellular responses. Ras-like protein belongs to the Rac subfamily of the Rho family of GTPases. RHOQ is involved in epithelial cell polarization processes. In addition, RHOQ plays a role in CFTR trafficking to the plasma membrane. RHOQ causes the formation of thin, actin-rich surface projections called filopodia.

Thyroxine binding globulin, also known as SERPINA7, is synthesized in the liver and carried in the blood.
SERPINA7 may be decreased or increased in a number of diseases. Its main value in diagnosis is to assess thyroid function by determining the amount of free T3/T4.
Thyroxine binding globulin, binds and transports thyroid hormones in the circulation. SERPINA7 carries the majority of the T3/T4 in the blood. SERPINA7 has only one binding site for T3/T4 and about 25% of Thyroxine binding globulin is usually saturated.

Fucosyltransferase 7 (FUT7) is a golgi stack membrane protein which is involved in the creation of sialyl-Lewis X antigens. The FUT7 protein leads the synthesis of the E-selectin-binding sialyl-Lewis X moiety. FUT7 catalyzes alpha-1,3 glycosidic linkages involved in the expression of sialyl Lewis X antigens.

Lumican also known as LUM belongs to the small leucine-rich proteoglycan (SLRP) family which comprises decorin, biglycan, fibromodulin, keratocan, epiphycan, and osteoglycin. Furthermore we can see that in these bifunctional molecules, the protein moiety binds collagen fibrils and the highly charged hydrophilic glycosaminoglycans regulate interfibrillar spacings. Lumican is the main keratan sulfate proteoglycan of the cornea however LUM is also distributed in interstitial collagenous matrices throughout the body. Lumican regulates collagen fibril organization and circumferential growth, corneal transparency, epithelial cell migration and tissue repair. Among the diseases associated with LUM is posterior amorphous corneal dystrophy.

SDF-1 (stromal cell-derived factor-1) is small cytokine belonging to the chemokine family that is officially designated Chemokine (C-X-C motif) ligand 12 (CXCL12). It is produced in two forms, SDF-1?/CXCL12a and SDF-1?/CXCL12b, by alternate splicing of the same gene. Chemokines are characterized by the presence of four conserved cysteines, which form two disulfide bonds. The CXCL12 proteins belong to the group of CXC chemokines, whose initial pair of cysteines are separated by one intervening amino acid. CXCL12 is strongly chemotactic for lymphocytes and has been implicated as an important cell co-ordinator during development. During embryogenesis it directs the migration of hematopoietic cells from foetal liver to bone marrow. Mice which were knocked-out for CXCL12 gene were lethal before the birth or within just 1 hour of life. As another role, CXCL12a alters also the electrophysiology of neurons. CXCL12 was shown to be expressend in many tissues in mice (including brain, thymus, heart, lung, liver, kidney, spleen and bone marrow).
The receptor for this chemokine is CXCR4, which was previously called fusin. This CXCL12-CXCR4 interaction used to be considered exclusive (unlike for other chemokines and their receptors), but recently it was suggested that CXCL12 is also bound by CXCR7 receptor. The gene for CXCL12 is located on human chromosome 10. In human and mouse both CXCL12 and CXCR4 show high identity of sequence: 99% and 90%, respectively.

Charged multivesicular body protein 3 (VPS24/CHMP3) is a member of the vacuolar sorting protein family and function as chromatin modifying proteins. VPS24 links directly with CHMP2 and CHMP4 for the disassembly of ESCRT-III complex in an ATP-dependent manner. During HIV-1 infection, the virus uses the ESCRT-III complex to mediate budding and exocytosis of viral proteins. VPS24 overexpression strongly hinders HIV-1 release.

Peptidase Inhibitor 16 (PI16) which a member of the CRISP family, is a putative serine protease inhibitor. PI16 interacts with PSP94/MSMB. PI16 is expressed in the prostate, testis, ovary and intestine. It also concentrates in prostate cancer patient's sera. PI16 may serve as a marker following prostatectomy for prostate cancer.