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Naked Cuticle (Nkd)
Naked cuticle (Nkd) is a conserved family of intracellular proteins encoded in most animal genomes. The original mutants were discovered by 1995 Nobel laureates Christiane Nüsslein-Volhard and Eric F. Wieschaus and colleagues in their genetic screens for pattern-formation mutants in the fruit fly ''Drosophila melanogaster''. The Nkd gene family was first cloned in the laboratory of Matthew P. Scott. Like many cleverly named fly mutants, the name "naked cuticle" derives from the fact that mutants lack most of the hair-like protrusions from their ventral cuticle and thus appear "naked". In Drosophila, nkd is a segment–polarity class gene that limits the spatial extent of Wnt signaling pathway activity, similar to how the Patched (Ptc) gene regulates the Hedgehog signaling pathway; i.e., Nkd and Ptc shape tissue gradients of Wnt and Hedgehog signaling. Nkd was linked to Wnt signaling based on expansion of Wnt signaling in nkd mutants, by overexpression of Nkd mimicking lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genome
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as regulatory sequences (see non-coding DNA), and often a substantial fraction of 'junk' DNA with no evident function. Almost all eukaryotes have mitochondria and a small mitochondrial genome. Algae and plants also contain chloroplasts with a chloroplast genome. The study of the genome is called genomics. The genomes of many organisms have been sequenced and various regions have been annotated. The International Human Genome Project reported the sequence of the genome for ''Homo sapiens'' in 200The Human Genome Project although the initial "finished" sequence was missing 8% of the genome consisting mostly of repetitive sequences. With advancements in technology that could handle sequenci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphipathic
An amphiphile (from the Greek αμφις amphis, both, and φιλíα philia, love, friendship), or amphipath, is a chemical compound possessing both hydrophilic (''water-loving'', polar) and lipophilic (''fat-loving'') properties. Such a compound is called amphiphilic or amphipathic. Common amphiphilic substances are soaps, detergents, and lipoproteins. The phospholipid amphiphiles are the major structural component of cell membranes. Amphiphiles are the basis for a number of areas of research in chemistry and biochemistry, notably that of lipid polymorphism. Organic compounds containing hydrophilic groups at both ends of the molecule are called bolaamphiphile, bolaamphiphilic. The micelles they form in the aggregate are prolate. Structure The lipophilic group is typically a large hydrocarbon Moiety (chemistry), moiety, such as a long chain of the form CH3(CH2)n, with n > 4. The hydrophilic group falls into one of the following categories: # charged groups #* anionic. Examples ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nkd2
Naked cuticle 2 (NKD2) is a human gene that encodes the protein Nkd2, one of the Naked cuticle (Nkd) family of proteins that regulate the Wnt signaling pathway. Both Nkd1 and Nkd2 proteins can bind to Dishevelled proteins (DVL1, DVL2, DVL3), but only Nkd2 can bind to the EGF-ligand family member TGF alpha Transforming growth factor alpha (TGF-α) is a protein that in humans is encoded by the TGFA gene. As a member of the epidermal growth factor (EGF) family, TGF-α is a mitogenic polypeptide. The protein becomes activated when binding to receptors ... and regulate its polarized secretion in cultured epithelial cells.{{cite journal , last1 = Li , first1 = C , last2 = Franklin , first2 = JL , last3 = Graves-Deal , first3 = R , last4 = Jerome , first4 = WG , last5 = Cao , first5 = Z , last6 = Coffey , first6 = RJ , date = Apr 2004 , title = Myristoylated Naked2 escorts transforming growth factor alpha to the basolateral plasma membrane of polarized epithelial cells , ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nkd1
Naked cuticle 1 (NKD1) is a human gene that encodes the protein Nkd1, a member of the Naked cuticle (Nkd) family of proteins that regulate the Wnt signaling pathway. Insects typically have a single Nkd gene, whereas there are two Nkd genes, Nkd1 and Nkd2, in most vertebrates studied to date (zebrafish appear to have additional homologous genes such as Nkd3). Nkd1 binds to the Dishevelled (Dvl) family of proteins (DVL1, DVL2, DVL3). Specific truncating NKD1 mutations identified in DNA mismatch repair deficient colon cancer that disrupt Nkd1/Dvl binding implicate these mutations as a cause of increased Wnt signaling in approximately 1% of human colon cancer, the majority of which have increased Wnt signaling due to mutations the adenomatous polyposis coli (APC), AXIN2, or rarely the beta-catenin Catenin beta-1, also known as beta-catenin (β-catenin), is a protein that in humans is encoded by the ''CTNNB1'' gene. Beta-catenin is a dual function protein, involved in regulation and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Importin
Importin is a type of karyopherin that transports protein molecules from the cell's cytoplasm to the nucleus. It does so by binding to specific recognition sequences, called nuclear localization sequences (NLS). Importin has two subunits, importin α and importin β. Members of the importin-β family can bind and transport cargo by themselves, or can form heterodimers with importin-α. As part of a heterodimer, importin-β mediates interactions with the pore complex, while importin-α acts as an adaptor protein to bind the nuclear localization signal (NLS) on the cargo. The NLS-Importin α-Importin β trimer dissociates after binding to Ran GTP inside the nucleus, with the two importin proteins being recycled to the cytoplasm for further use. Discovery Importin can exist as either a heterodimer of importin-α/β or as a monomer of Importin-β. Importin-α was first isolated in 1994 by a group includinEnno Hartmann based at the Max Delbrück Center for Molecular Medicine. The p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anopheles Gambiae
The ''Anopheles gambiae'' complex consists of at least seven morphologically indistinguishable species of mosquitoes in the genus ''Anopheles''. The complex was recognised in the 1960s and includes the most important vectors of malaria in sub-Saharan Africa, particularly of the most dangerous malaria parasite, ''Plasmodium falciparum''. It is one of the most efficient malaria vectors known. The ''An. gambiae'' mosquito additionally transmits ''Wuchereria bancrofti'' which causes lymphatic filariasis, a symptom of which is elephantiasis. Discovery and elements The ''Anopheles gambiae'' complex or ''Anopheles gambiae'' sensu lato was recognized as a species complex only in the 1960s. The ''A. gambiae'' complex consists of: * '' Anopheles arabiensis'' * ''Anopheles bwambae'' * ''Anopheles melas'' * ''Anopheles merus'' * ''Anopheles quadriannulatus'' * ''Anopheles gambiae'' sensu stricto (s.s.) * ' * ''Anopheles amharicus'' The individual species of the complex are morphological ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosquito
Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin ''culex'' meaning " gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish for "little fly". Mosquitoes have a slender segmented body, one pair of wings, one pair of halteres, three pairs of long hair-like legs, and elongated mouthparts. The mosquito life cycle consists of egg, larva, pupa, and adult stages. Eggs are laid on the water surface; they hatch into motile larvae that feed on aquatic algae and organic material. These larvae are important food sources for many freshwater animals, such as dragonfly nymphs, many fish, and some birds such as ducks. The adult females of most species have tube-like mouthparts (called a proboscis) that can pierce the skin of a host and feed on blood, which contains protein and iron needed to produce eggs. Thousands of mosquito species feed on the blood of various hosts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TGF Alpha
Transforming growth factor alpha (TGF-α) is a protein that in humans is encoded by the TGFA gene. As a member of the epidermal growth factor (EGF) family, TGF-α is a mitogenic polypeptide. The protein becomes activated when binding to receptors capable of protein kinase activity for cellular signaling. TGF-α is a transforming growth factor that is a ligand for the epidermal growth factor receptor, which activates a signaling pathway for cell proliferation, differentiation and development. This protein may act as either a transmembrane-bound ligand or a soluble ligand. This gene has been associated with many types of cancers, and it may also be involved in some cases of cleft lip/palate. Synthesis TGF-α is synthesized internally as part of a 160 (human) or 159 (rat) amino acid transmembrane precursor.Ferrer, I.; Alcantara, S.; Ballabriga, J.; Olive, M.; Blanco, R.; Rivera, R.; Carmona, M.; Berruezo, M.; Pitarch, S.; Planas, A. Transforming growth factor- α (TGF-α) and epide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epidermal Growth Factor
Epidermal growth factor (EGF) is a protein that stimulates cell growth and differentiation by binding to its receptor, EGFR. Human EGF is 6-k Da and has 53 amino acid residues and three intramolecular disulfide bonds. EGF was originally described as a secreted peptide found in the submaxillary glands of mice and in human urine. EGF has since been found in many human tissues, including platelets, submandibular gland (submaxillary gland), and parotid gland. Initially, human EGF was known as urogastrone. Structure In humans, EGF has 53 amino acids (sequence NSDSECPLSHDGYCLHDGVCMYIEALDKYACNCVVGYIGERCQYRDLKWWELR), with a molecular mass of around 6 kDa. It contains three disulfide bridges (Cys6-Cys20, Cys14-Cys31, Cys33-Cys42). Function EGF, via binding to its cognate receptor, results in cellular proliferation, differentiation, and survival. Salivary EGF, which seems to be regulated by dietary inorganic iodine, also plays an important physiological role in the maintenance of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histidine
Histidine (symbol His or H) is an essential amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated –NH3+ form under biological conditions), a carboxylic acid group (which is in the deprotonated –COO− form under biological conditions), and an imidazole side chain (which is partially protonated), classifying it as a positively charged amino acid at physiological pH. Initially thought essential only for infants, it has now been shown in longer-term studies to be essential for adults also. It is encoded by the codons CAU and CAC. Histidine was first isolated by Albrecht Kossel and Sven Gustaf Hedin in 1896. It is also a precursor to histamine, a vital inflammatory agent in immune responses. The acyl radical is histidyl. Properties of the imidazole side chain The conjugate acid (protonated form) of the imidazole side chain in histidine has a p''K''a of approximately 6.0. Thus, below a pH of 6, the imidazole ring ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Helix
The alpha helix (α-helix) is a common motif in the secondary structure of proteins and is a right hand-helix conformation in which every backbone N−H group hydrogen bonds to the backbone C=O group of the amino acid located four residues earlier along the protein sequence. The alpha helix is also called a classic Pauling–Corey–Branson α-helix. The name 3.613-helix is also used for this type of helix, denoting the average number of residues per helical turn, with 13 atoms being involved in the ring formed by the hydrogen bond. Among types of local structure in proteins, the α-helix is the most extreme and the most predictable from sequence, as well as the most prevalent. Discovery In the early 1930s, William Astbury showed that there were drastic changes in the X-ray fiber diffraction of moist wool or hair fibers upon significant stretching. The data suggested that the unstretched fibers had a coiled molecular structure with a characteristic repeat of ≈. Astb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EF Hand
The EF hand is a helix–loop–helix structural domain or ''motif'' found in a large family of calcium-binding proteins. The EF-hand motif contains a helix–loop–helix topology, much like the spread thumb and forefinger of the human hand, in which the Ca2+ ions are coordinated by ligands within the loop. The motif takes its name from traditional nomenclature used in describing the protein parvalbumin, which contains three such motifs and is probably involved in muscle relaxation via its calcium-binding activity. The EF-hand consists of two alpha helices linked by a short loop region (usually about 12 amino acids) that usually binds calcium ions. EF-hands also appear in each structural domain of the signaling protein calmodulin and in the muscle protein troponin-C. Calcium ion binding site The calcium ion is coordinated in a pentagonal bipyramidal configuration. The six residues involved in the binding are in positions 1, 3, 5, 7, 9 and 12; these residues are denoted by X ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
