Search results

Retinol-binding proteins (RBP) are a family of proteins with various functions. Retinol and retinoic acid play crucial roles in the modulation of gene expression and overall development of an embryo. However, deficit or excess of either one of these substances can cause early embryo mortality or developmental malformations. Regulation of transport and metabolism of retinol necessary for a successful pregnancy is accomplished via RBP. Retinol binding proteins have been identified within the uterus, embryo, and extraembryonic tissue of the bovine, ovine, and porcine, therefore RBP takes part in proper retinol exposure to the embryo and successful transport at the maternal-fetal interface.

REG protein was shown to be stimulated during the regeneration of pancreatic islets. Since then, many Reg-related proteins have been identified in humans and other animals. In human, the four REG family genes, i.e., REG 1 alpha, REG 1 beta, REG-related sequence (RS) and HIP/PAP, have so far been isolated. These Reg-related proteins are classified into four subfamilies according to their amino-acid sequences, but they share a similar structure and physiological function. Reg protein is a growth factor for pancreatic beta cells and also suggests that the administration of Reg protein could be used as another therapeutic approach for diabetes mellitus. Human REG cDNA which encodes a 166-amino acid protein with a 22-amino acid signal peptide. The amino acid sequence of human REG protein has 68% homology to that of rat Reg protein.
Reg I was found to be expressed mainly in pancreatic beta and acinoductular cells as well as gastric fundic enterochromaffin-like (ECL) cells. Reg I production in ECL cells is stimulated by gastrin, as well as by the proinflammatory cytokine, cytokine-induced neutrophil chemoattractant (CINC)-2Beta. In patients with chronic hypergastrinemia, Reg production is stimulated, with the increased proliferation of gastric mucosal cells. Patients with Helicobacter pylori infection also showed increased Reg production in the gastric mucosa, partly via increased plasma gastrin concentration and partly via increased proinflammatory cytokine production. The serum concentration of the reg-protein was significantly higher in patients with various pancreatic diseases than in normal controls, and was also significantly higher in patients with acute pancreatitis or chronic relapsing pancreatitis than in patients with chronic pancreatitis. Furthermore, the serum PSP/reg-protein concentration was also significantly increased in liver cirrhosis, choledocholithiasis, and various cancers of the digestive system.

Prolactin is a neuroendocrine hormone synthesized primarily by the pituitary gland but also a variety of other cell types including the placenta, brain and uterus. Its primary function is to promote and maintain lactation but has also been shown to have a role in breast cancer development, regulation of reproductive function and immunoregulation.

Once Chinese hamster K12 cells are starved from glucose, the synthesis of GRP (glucose-regulated protein) expressed. HSPA5 also called BiP, is part of the HSP70 family and plays a role in the folding and assembly of proteins in the endoplasmic reticulum. HSPA5 plays a key role in monitoring protein transport through the cell.
HSPA5 is a stress response protein which is induced by agents or conditions that adversely affect endoplasmic reticulum function. HSPA5 is crucial for the proper glycosylation, folding as well as for the maintenance of cell homeostasis and the prevention of apoptosis. HSPA5 is differentially expressed in the dorsolateral prefrontal cortex from patients with schizophrenia. HSPA5 guides posttranslational hepatitis B virus large envelope protein import into the mammalian ER. HSPA5 actively regulates multiple malignant phenotypes, including cell growth, migration, and invasion.

Protein Tyrosine Phosphatase Receptor Type C, also known as PTPRC, which is a vital regulator of T- and B-cell antigen receptor signaling, is also a part of the protein tyrosine phosphatase (PTP) family. PTPs are signaling molecules which regulate a variety of cellular processes including differentiation, cell growth, mitosis, and oncogenic transformation. PTPRC contains an extracellular domain, a single transmembrane segment and 2 tandem intracytoplasmic catalytic domains, and therefore is classified as a receptor type PTP.

NHP2L1 is a member of the ribosomal protein L7Ae family. NHP2L1 protein limited to the nucleus, primarily focused in the dense fibrillar component of the nucleolus. NHP2L1 directly binds to the 5' stem-loop of U4 snRNA and has a vital part in the late stage of spliceosome assembly, prior to step I of splicing catalysis.

HSPH1 analysis is used as an indicator and as a diagnostic aid in problematic lesions. HSPH1 chaperones the responses to endoplasmic reticulum (ER) stress during its interactions with GRP78 and GSK3, and without HSP105 cell death following ER stress proceeds by a non-caspase-3-dependent process. HSPH1 is highly expressed in a variety of human tumors. HSPH1 is a mammalian member of the HSP105/110 family, a diverged subgroup of the HSP70 family. HSP105 has 2 isoforms, alpha and beta. Hsp105a associates with Hsp70/Hsc70 as complexes in vivo and regulates the chaperone activity of Hsp70/Hsc70 negatively in vitro and in vivo.

NRG1 is one of 4 proteins in the neuregulin family which act on the EGFR family of receptors. NRG1 was initially identified as a 44kDa glycoprotein that interacts with the ERBB2 receptor tyrosine kinase to increase its phosphorylation on tyrosine residues. In various brain areas, NRG1 is expressed at synaptic regions and its processing can be regulated by neuronal activity. The HRG-beta3variant of NRG1, along with HRG-alpha, beta1 and beta2 variants, was identified in various normal tissues and cancer cell lines.

Endophilin-B2 (SH3GLB2) belongs to the endophilin B subgroup. The endophilins comprise a family of proteins that relates with amphiphysin, synaptojanin and dynamin and are involved in presynaptic vesicle trafficking at nerve terminals.The expression patterns of the endophilins are coherent with their cellular functions at the neuronal synapse. SH3GLB2 is ubiquitously expressed however presents highest levels in brain, adult lung, ovary, and spinal cord.Low levels of SH3GLB2 are found in Down syndrome and reflect brain dysgenesis.

FABP1 (Fatty acid binding protein1) encodes the fatty acid binding protein found in liver. FABP1 is composed of ten antiparallel beta strands that form a barrel with a bigger binding pocket than the other FABPs allowing it to accommodate two fatty acid. This protein binds free fatty acids and their coenzyme A derivatives, bilirubin, and some other small molecules in the cytoplasm; it may be involved in intracellular lipid transport and metabolism.

Ribosomes, the organelles which catalyze protein synthesis, contain a small 40S subunit and a large 60S subunit. Together these subunits are composed of 4 RNA species and nearly 80 structurally different proteins. RPL34 is a member of the L34E family of ribosomal proteins and it encodes a ribosomal protein which is a component of the 60S subunit. RPL34 is found in the cytoplasm and has been mapped to 4q though it was initially believed it is located at 17q21. Transcript variants which are a result of alternative splicing, alternative transcription initiation sites, and/or alternative polyadenylation exist; all encode the same protein. As is typical for genes encoding ribosomal proteins, there are several processed pseudogenes of this gene spread all over the genome.

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.

HtrA2 also called Omi is a mammalian serine protease at high temperatures and has a chaperone activity at low temperature. The full-length HtrA2 is synthesized as a precursor protein and then targeted to the mitochondria where it is matured by the removal of N-terminal 133 residues. Mature HtrA2 consists of a putative transmembrane domain; an inhibitor of apoptosis protein (IAP)-binding motif; a single C-terminal PDZ domain that mediates protein-protein interactions. Recently, HtrA2 has known to contribute both to caspase-dependent and caspase-independent cell death.

Adiponectin is an adipocyte specific secreted protein that circulates in the plasma. It is induced during adipocyte differentiation and its secretion is stimulated by insulin. Mouse adiponectin shares about 83% amino acid identity with that human. Adiponectin plays a role in various physiological processes such as energy homeostasis and obesity. Adiponectin is reduced in obese humans, and decreased level is associated with insulin resistance and hyperinsulinemia.

DHH is part of the Hedgehog family which encodes signaling molecules that are involved in regulating morphogenesis. DHH protein is a precursor that is autocatalytically cleaved, the N-terminal portion is soluble and contains the signalling activity while the C-terminal portion is involved in precursor processing. Additionally, the C-terminal product covalently attaches a cholesterol moiety to the N-terminal product, restricting the N-terminal product to the cell surface and preventing it from freely diffusing throughout the organism. Defects in DHH protein have been associated with partial gonadal dysgenesis (PGD) accompanied by minifascicular polyneuropathy. DHH plays a role both male gonadal differentiation and perineurial development.
DHH plays a role in intercellular signaling which is essential for a variety of patterning events during development. DHH functions as a spermatocyte survival factor in the testes & is essential for testes development.

Adiponectin is an important negative regulator in hematopoiesis and immune systems. It may be involved in ending inflammatory responses through its inhibitory functions. Inhibits endothelial nf-kappa-b signaling through a camp-dependent pathway. Inhibits tnf-alpha- induced expression of endothelial adhesion molecules. Involved in the control of fat metabolism and insulin sensitivity.

Apolipoprotein-D is mainly associated with high density lipoproteins in human plasma. Apolipoprotein-D is an atypical apolipoprotein and, based on its primary structure, Apolipoprotein-D is a member of the lipocalin family. Lipocalins adopt a beta-barrel tertiary structure and transport small hydrophobic ligands. Apolipoprotein-D binds cholesterol, progesterone, pregnenolone, bilirubin and arachidonic acid.
Apolipoprotein-D is expressed in numerous tissues having high levels of expression in spleen, testes and brain. Apolipoprotein-D is present at high concentrations in the cyst fluid of women with gross cystic disease of the breast, a condition associated with increased risk of breast cancer. Apolipoprotein-D accumulates in regenerating peripheral nerves and in the cerebrospinal fluid of patients with neurodegenerative conditions, such as Alzheimer's disease. Apolipoprotein-D participates in maintenance and repair within the central and peripheral nervous systems. Apolipoprotein-D is a multi-ligand, multi-functional transporter and transports a ligand from 1 cell to another within an organ, scavenge a ligand within an organ for transport to the blood or could transport a ligand from the circulation to specific cells within a tissue.

Phosphoglycolate phosphatase (PGP) is discovered in all tissues including red cells, lymphocytes and cultured fibroblasts (at protein level). PGP is most active in skeletal muscle and cardiac muscle. The catalytic activity of PGP is 2-phosphoglycolate + H2O = glycolate + phosphate. Diseases associated with PGP include tardive dyskinesia and polycystic kidney disease.

Mitochondrial ribosomes (mitoribosomes) consist of a small 28S subunit and a large 39S subunit. Mitochondrial Ribosomal Protein S28, also known as MRPS28, is a protein coding gene which encodes a 28S subunit protein which is known as mitochondrial ribosomal protein S35.

High Mobility Group Nucleosomal Binding Domain 3 (HMGN3), binds thyroid hormone receptor beta, however it occurs only in the presence of thyroid hormone. Thyroid hormone receptors are hormone-dependent transcription factors which regulate expression of a variety of particular target genes. HMGN3 is considered to reduce the compactness of the chromatin fiber in nucleosomes, in that way enhancing transcription from chromatin templates.

HSF2BP, also known as HSF2 binding protein links with HSF2. This interaction takes place between the trimerization domain of HSF2 and the amino terminal hydrophilic region of HSF2BP which contains two leucine zipper motifs. Therefore, HSF2BP is involved in modulating HSF2 activation.

Nipsnap Homolog 1 (NIPSNAP1) belongs to the NipSnap family. NIPSNAP1 may take part in vesicular transport. A similar protein in mice inhibits the calcium channel TRPV6, and it is localized to the inner mitochondrialmembrane as well, where it may be involved in mitochondrial DNA maintenance. A pseudogene of NIPSNAP1 is located onthe short arm of chromosome 17. Among the diseases associated with NIPSNAP1 are maple syrup urine disease, and phenylketonuria.

IGFBP3 is a member of the IGFBP family and encodes a protein with an IGFBP domain and a thyroglobulin type-I domain. The protein forms a ternary complex with IGFALS and either IGF I or II. In this form, it circulates in the plasma, prolonging the half-life of IGFs and altering their interaction with cell surface receptors. Alternate transcriptional splice variants, encoding different isoforms, have been characterized.

BLVRB (EC 1.3.1.24) catalyzes electron transfer from reduced pyridine nucleotides to flavins as well as methylene blue, pyrroloquinoline quinone, riboflavin, or methemoglobin. BLVRB is involved in protecting cells from oxidative damage or in regulating iron metabolism. BLVRB converts biliverdin to bilirubin in the liver, converting a double-bond between the second and third pyrrole ring into a single-bond. BLVRB plays a role as in human erythrocytic heme catabolic pathway and most mammalian species. Biliverdin reductase is abundantly expressed in kidney, spleen, liver and brain as well as at lower levels in the thymus and minimal levels being detected in testis.