Search results

Dihydrofolate reductase (DHFR) is an enzyme that reduces dihydrofolic acid to tetrahydrofolic acid, with NADPH as electron donor that can be converted to the kinds of tetrahydrofolate cofactors applied in 1-carbon transfer chemistry. DHFR converts dihydrofolate into tetrahydrofolate, which is a methyl group shuttle required for the de novo synthesis of purines, thymidylic acid, and specific amino acids. Even though the functional DHFR gene is mapped to chromosome 5, numerous intronless processed pseudogenes or dihydrofolate reductase-like genes are identified on separate chromosomes. DHFR deficiency is associated with megaloblastic anemia. DHFR knockdown plays a role in the anticancer activity of 2-hydroxyoleic acid. DHFR gene insertion/deletion polymorphism is linked to variation in serum and red blood cell folate concentrations in women.

HSP27 (also known as the Estrogen-Regulated 24K protein, and hsp 28) is a member of the mammalian small heat shock protein family. Hsp27 is expressed constitutively in many tissues and its expression is increased to high levels after various types of stress including elevated temperatures, toxic metals, drugs and oxidants. Also, Hsp27 is phosphorylated in vivo on three phosphorylation sites (Ser15, Ser78 and Ser82) by protein kinases including MAPKAP kinase 2 and the stress-activated protein kinase SAPK2 (p38).

HSPB3 is a muscle-specific small heat shock protein which is expressed specially in heart and skeletal muscle. Mammalian small heat shock proteins (sHSP) are highly expressed proteins with varied roles, including the assembly and impounding of multi-protein complexes, transportation of nascent polypeptide chains thru cellular membranes and regulation of protein folding. HSPB3 perform as an ATP-dependent chaperone protein which takes part in the refolding of denatured proteins and inhibition of actin polymerization.

ATOH1 activates E box-dependent transcription in collaboration with TCF3/E47, but the activity is entirely provoked by the negative regulator of neurogenesis HES1. ATOH1 takes part in the differentiation of divisions of neural cells by activating E box-dependent transcription.

Mitochondrial methylglutaconyl-CoA hydratase (AUH) is involved in the amino acid degradation pathway by catalyzing the conversion of 3-methylglutaconyl-CoA to 3-hydroxy-3-methylglutaryl-CoA and water. AUH Human is expressed as a single mRNA species of 1.8 kb, and translated as a 40kDa precursor protein which is consequently processed to a 32kDa mature form. AUH has a very low enoyl-CoA hydratase activity. The AUH protein binds to the AU-rich element (ARE), which is a common element found in the 3' UTR of rapidly decaying mRNA such as c-fos, c-myc and granulocyte/ macrophage colony stimulating factor. AU-rich elements are involved in directing RNA to rapid degradation and deadenylation. In addition, AUH is homologous to enol-CoA hydratase, which is an enzyme involved in fatty acid degradation, and has been shown to have intrinsic hydratase enzymatic activity. AUH is therefore a bifunctional chimera between RNA binding and metabolic enzyme activity.

NSL1 holds two coiled-coil domains.NSL1 proteins, localized to kinetochores - chromosome associated structures which attach to microtubules and mediate chromosome movements throughout cell division. NSL1 is a fragment of a conserved protein complex that hold two chromodomain-containing proteins and a component of the outer plate of the kinetochore. NSL1 connect centromeric heterochromatin with the outer kinetochore structure. Several transcript variants are known to encod different isoforms for this gene.

Alpha-parvin (PARVA) belongs to the parvin family of actin-binding proteins. PARVA has a role in the regulation of cell adhesion, cytoskeleton organization, motility and survival as well as in ciliogenesis. Parvins are related with focal contacts and contain calponin homology domains which connect to actin filaments. PARVA is extensively expressed, with the highest levels in heart, skeletal muscle, kidney and liver.

CAPSL is a calcium-binding protein holding two conserved calcium-binding motifs (EF-hands) which are found in a superfamily of calcium sensors and calcium signal modulators. In addition, the CAPSL gene is in the same linkage disequilibrium (LD) block as the IL7R gene and there is well known association between the CAPSL-IL7R locus and type 1 diabetes.

Endothelial cells express three different vascular endothelial growth factor (VEGF) receptors, belonging to the family of receptor tyrosine kinases (RTKs). They are named VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1), and VEGFR-3 (Flt-4). Their expression is almost exclusively restricted to endothelial cells, but VEGFR-1 can also be found on monocytes. All VEGF-receptors have seven immunoglobulin-like extracellular domains, a single transmembrane region and an intracellular split tyrosine kinase domain. VEGFR-2 has a lower affinity for VEGF than the Flt-1 receptor, but a higher signalling activity. Mitogenic activity in endothelial cells is mainly mediated by VEGFR-2 leading to their proliferation. Differential splicing of the flt-1 gene leads to the formation of a secreted, soluble variant of VEGFR-1 (sVEGFR-1). No naturally occurring, secreted forms of VEGFR-2 have so far been reported. The binding of VEGF165 to VEGFR-2 is dependent on heparin.

Killer-cell immunoglobulin-like receptors (KIRs), are a family of cell surface glycoproteins found on Natural Killer (NK) Cells, which are important cells of the immune system. They control the killing function of these cells by interacting with MHC class I molecules, which are expressed on all cell types. This interaction allows them to identify virally infected cells or tumor cells that have a distinctive low level of Class I MHC on their surface. The majority of KIRs are inhibitory, which means that their recognition of MHC suppresses the cytotoxic activity of their NK cell. Only a limited number of KIRs have the capacity to activate cells.
The KIR genes are found in a cluster on chromosome 19q13.4 within the 1 Mb leukocyte receptor complex (LRC). KIR molecules are extremely polymorphic, meaning their gene sequences differ significantly between individuals, so that different individuals have different arrays/repertoires of KIR genes.
The KIR proteins are categorized by the number of extracellular immunoglobulin domains (2D or 3D) and by whether they have a long (L) or short (S) cytoplasmic domain. KIR proteins with the long cytoplasmic domain transduce inhibitory signals upon ligand binding via an immune tyrosine-based inhibitory motif (ITIM). Whereas KIR proteins with the short cytoplasmic domain lack the ITIM motif and instead associate with the TYRO protein tyrosine kinase binding protein to transduce activating signals.
KIR2DL1 is an inhibitory Killer Cell Ig-like Receptor (KIR, previously called p58 KIR, p58.1, cl-42, NKAT1, or KIR-K6), which recognizes class I MHC molecules (HLA-Cw2, -Cw4, -Cw5, and Cw6). The extracellular domain of KIR2DL1 was over expressed as insoluble protein aggregates (inclusion bodies).

Antioxidant enzyme Glutathione S- Transferase (GST) is thought to do the primary cellular defense mechanism against reactive oxygen species. GST reduces lipid hydroperoxides through its Se-independent glutathione peroxidase activity. The enzyme also detoxifies lipid peroxidation end products such as 4-hydroxynonenal (4-HNE).
The soluble GST is a 26 kDa protein which occurs as a dimer in all aerobic organisms. Each monomer has two domains, one that binds GSH and is an /-structure similar to thioredoxin and the other, all helical, that binds the hydrophobic substrate. The GST -fusion protein expression system is a widely used recombinant protein expression system that allows a peptide or a regulatory protein domain to be expressed as a fusion to the C-terminus of Schistosoma japonicum GST. Fusion proteins also possess GST -enzymatic activity and can undergo dimerization similar to in vivo. The fusion protein can be purified via GST -affinity column chromatography. In most cases, the desired peptides or domains are removed from GST by applying a specific protease that recognizes and cleaves the linker between the protein domain and GST. The technique has been widely used to generate different kinds of proteins for crystallization, molecular immunology studies, the production of vaccines and studies involving protein-protein and protein-DNA interactions.

GTF2B is one of the ubiquitous factors needed for transcription initiation by RNA polymerase II preinitiation factor. GTF2B localizes to the nucleus where it forms a complex (the DAB complex) with transcription factors IID and IIA. GTF2 plays a role as a bridge between IID, which initially recognizes the promoter sequence, and RNA polymerase II. GTF2B is involved in the selection of the transcription start site.

Parvalbumin alpha (PVALB) is a member of a larger group of EF hand proteins. PVALB is a high affinity calcium ion-binding protein which is structurally and functionally similar to calmodulin and troponin C. Parvalbumin is expressed in a specific population of GABAergic interneurones which are believed to have a role in maintaining the balance between excitation and inhibition in the cortex as well as the hippocampus.

VSNL1 is a member of the visinin/recoverin subfamily of neuronal calcium sensor proteins. VILIP1 is strongly expressed in granule cells of the cerebellum where it associates with membranes in a calcium-dependent manner and modulates intracellular signaling pathways of the central nervous system by directly or indirectly regulating the activity of adenylyl cyclase. Changes in cellular expression of VSNL1 were found in hipppocampi of schizophrenics, since more interneurons showed immunoreactivity.
VILIP1 is expressed in pancreatic beta-cells. VILIP-1 interacts with cell membrane and actin-based cytoskeleton. VSNL1 modulates cAMP-accumulation in C6 glioma cells. HLP3 modulates cGMP-accumulation in transfected neural cells and cerebellar granule neurons.

The 14-3-3 family of proteins plays a key regulatory role in signal transduction, checkpoint control, apoptotic and nutrient-sensing pathways. 14-3-3 proteins are highly conserved and ubiquitously expressed. There are at least seven isoforms, β, γ, ε, σ, ζ, τ and η that have been identified in mammals. The 14-3-3 epsilon, a subtype of the 14-3-3 family of proteins, was thought to be brain and neuron-specific. It has been shown to interact with CDC25 phosphatases, RAF1 and IRS1 proteins, suggesting its role in diverse biochemical activities related to signal transduction, such as cell division and regulation of sensitivity. It has also been implicated in the pathogenesis of small cell lung cancer.

YWHAH belongs to the 14-3-3 family of proteins which mediate signal transduction by binding to phosphoserine-containing proteins. 14-3-3 ETA is found in plants and mammals, and there is 99% identity to the mouse, rat and bovine orthologs. YWHAH gene contains a 7 base pair repeat sequence in its 5' UTR, and changes in the number of this repeat has been associated with early-onset schizophrenia.
14-3-3 eta is specific to the site of joint inflammation.
14-3-3 proteins are colocalized with Lewy bodies in Parkinson disease, though there is no specific staining for the 14-3-3 eta subunit.
There are 3 different isoforms types of 14-3-3: Beta, Gamma and ETA that are DAL-1/Protein 4.1B-binding proteins.

Zinc Finger HIT-Type Containing 3 (ZNHIT3) which contains one HIT-type zinc finger, requires the presence of thyroid hormone for its interaction. Thyroid receptor interacting proteins particularly interact with the ligand binding domain of the thyroid receptor (TR).

RNA methyltransferase-like protein 1, also known as RNMTL1 is a member of the RNA methyltransferase TrmH family. RNMTL1 is probable RNA methyltransferase and expressed at an equal level in normal liver and hepatocarcinoma.

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.

Adenylosuccinate lyase (ADSL) is an enzyme which converts adenylosuccinate to AMP and fumarate as part of the purine nucleotide cycle. ADSL is involved in both de novo synthesis of purines and formation of adenosine monophosphate from inosine monophosphate. ADSL catalyzes 2 reactions in AMP biosynthesis: the removal of a fumarate from succinylaminoimidazole carboxamide (SAICA) ribotide to yield aminoimidazole carboxamide ribotide (AICA) and removal of fumarate from adenylosuccinate to yield AMP. Defects in the ADSL are the cause of adenylosuccinase deficiency (ADSL deficiency). ADSL deficiency is an autosomal recessive disorder distinguished by the accumulation in the body fluids of succinylaminoimidazole-carboxamide riboside (SAICA-riboside) and succinyladenosine (S-Ado). Adenylosuccinase deficiency results in succinylpurinemic autism, psychomotor retardation, and in some cases, growth retardation associated with muscle wasting and epilepsy.

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.

Uteroglobin (SCGB1A1) which belongs to the Secretoglobin (SCGBs) superfamily, is a multifunctional protein that exerts anti-inflammatory and anti-tumorigenic effects by binding small hydrophobic molecules such as phospholipids and prostaglandins. Uteroglobin is involved in numerous functions including anti-inflammation, inhibition of phospholipase A2 and the sequestering of hydrophobic ligands. SCGB1A1 is expressed by Clara cells, the non-ciliated, non-mucous secretory cells predominant in lung bronchioles, and by other epithelia which communicate with the external environment. On top of sequestering pro-inflammatory mediators and carcinogens, Uteroglobin is implicated in the inhibition of cell migration and invasion, platelet aggregation, and T cell differentiation. SCGB1A1 gene defects are associated with a susceptibility to asthma.