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Nodularin
Nodularins are potent toxins produced by the cyanobacterium '' Nodularia spumigena'', among others. This aquatic, photosynthetic cyanobacterium forms visible colonies that present as algal blooms in brackish water bodies throughout the world. The late summer blooms of ''Nodularia spumigena'' are among the largest cyanobacterial mass occurrences in the world. Cyanobacteria are composed of many toxic substances, most notably of microcystins and nodularins: the two are not easily differentiated. A significant homology of structure and function exists between the two, and microcystins have been studied in greater detail. Because of this, facts from microcystins are often extended to nodularins. Nodularin-R is the predominant toxin variant, though 10 variants of nodularin have been discovered to date. Nodularins are cyclic nonribosomal pentapeptides and contain several unusual non-proteinogenic amino acids such as N-methyl-didehydroaminobutyric acid and the β-amino acid ADDA. Thes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nodularin Key Sites
Nodularins are potent toxins produced by the cyanobacterium ''Nodularia spumigena'', among others. This aquatic, photosynthetic cyanobacterium forms visible colonies that present as algal blooms in brackish water bodies throughout the world. The late summer blooms of ''Nodularia spumigena'' are among the largest cyanobacterial mass occurrences in the world. Cyanobacteria are composed of many toxic substances, most notably of microcystins and nodularins: the two are not easily differentiated. A significant homology of structure and function exists between the two, and microcystins have been studied in greater detail. Because of this, facts from microcystins are often extended to nodularins. Nodularin-R is the predominant toxin variant, though 10 variants of nodularin have been discovered to date. Nodularins are cyclic nonribosomal pentapeptides and contain several unusual non-proteinogenic amino acids such as N-methyl-didehydroaminobutyric acid and the β-amino acid ADDA. These c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanotoxins
Cyanotoxins are toxins produced by cyanobacteria (also known as blue-green algae). Cyanobacteria are found almost everywhere, but particularly in lakes and in the ocean where, under high concentration of phosphorus conditions, they reproduce exponentially to form blooms. Blooming cyanobacteria can produce cyanotoxins in such concentrations that they poison and even kill animals and humans. Cyanotoxins can also accumulate in other animals such as fish and shellfish, and cause poisonings such as shellfish poisoning. Some of the most powerful natural poisons known are cyanotoxins. They include potent neurotoxins, hepatotoxins, cytotoxins, and endotoxins. Despite the similarity in name, they are unrelated to cyanides. Exposure to cyanobacteria can result in gastro-intestinal and hayfever symptoms or pruritic skin rashes. Exposure to the cyanobacteria neurotoxin BMAA may be an environmental cause of neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), Parkinson's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microcystins
Microcystins—or cyanoginosins—are a class of toxins produced by certain freshwater cyanobacteria, commonly known as blue-green algae. Over 250 different microcystins have been discovered so far, of which microcystin-LR is the most common. Chemically they are cyclic heptapeptides produced through nonribosomal peptide synthases. Cyanobacteria can produce microcystins in large quantities during algal blooms which then pose a major threat to drinking and irrigation water supplies, and the environment at large. Characteristics Microcystins—or cyanoginosins—are a class of toxins produced by certain freshwater cyanobacteria; primarily ''Microcystis aeruginosa'' but also other ''Microcystis'', as well as members of the ''Planktothrix'', ''Anabaena'', ''Oscillatoria'' and ''Nostoc'' genera. Over 250 different microcystins have been discovered so far, of which microcystin-LR is the most common. Chemically they are cyclic heptapeptides produced through nonribosomal peptide synth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microcystin
Microcystins—or cyanoginosins—are a class of toxins produced by certain freshwater cyanobacteria, commonly known as blue-green algae. Over 250 different microcystins have been discovered so far, of which microcystin-LR is the most common. Chemically they are cyclic heptapeptides produced through nonribosomal peptide synthases. Cyanobacteria can produce microcystins in large quantities during algal blooms which then pose a major threat to drinking and irrigation water supplies, and the environment at large. Characteristics Microcystins—or cyanoginosins—are a class of toxins produced by certain freshwater cyanobacteria; primarily '' Microcystis aeruginosa'' but also other '' Microcystis'', as well as members of the '' Planktothrix'', ''Anabaena'', '' Oscillatoria'' and '' Nostoc'' genera. Over 250 different microcystins have been discovered so far, of which microcystin-LR is the most common. Chemically they are cyclic heptapeptides produced through nonribosomal peptid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclic Peptides
Cyclic peptides are polypeptide chains which contain a circular sequence of bonds. This can be through a connection between the amino and carboxyl ends of the peptide, for example in cyclosporin; a connection between the amino end and a side chain, for example in bacitracin; the carboxyl end and a side chain, for example in colistin; or two side chains or more complicated arrangements, for example in amanitin. Many cyclic peptides have been discovered in nature and many others have been synthesized in the laboratory. Their length ranges from just two amino acid residues to hundreds. In nature they are frequently antimicrobial or toxic; in medicine they have various applications, for example as antibiotics and immunosuppressive agents. Thin-Layer Chromatography (TLC) is a convenient method to detect cyclic peptides in crude extract from bio-mass. Classification Cyclic peptides can be classified according to the types of bonds that comprise the ring. *Homodetic cyclic peptides, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nonribosomal Peptide
Nonribosomal peptides (NRP) are a class of peptide secondary metabolites, usually produced by microorganisms like bacteria and fungi. Nonribosomal peptides are also found in higher organisms, such as nudibranchs, but are thought to be made by bacteria inside these organisms. While there exist a wide range of peptides that are not synthesized by ribosomes, the term ''nonribosomal peptide'' typically refers to a very specific set of these as discussed in this article. Nonribosomal peptides are synthesized by nonribosomal peptide synthetases, which, unlike the ribosomes, are independent of messenger RNA. Each nonribosomal peptide synthetase can synthesize only one type of peptide. Nonribosomal peptides often have cyclic and/or branched structures, can contain non- proteinogenic amino acids including D-amino acids, carry modifications like '' N''-methyl and ''N''-formyl groups, or are glycosylated, acylated, halogenated, or hydroxylated. Cyclization of amino acids against the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carcinogenic
A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive substances are considered carcinogens, but their carcinogenic activity is attributed to the radiation, for example gamma rays and alpha particles, which they emit. Common examples of non-radioactive carcinogens are inhaled asbestos, certain dioxins, and tobacco smoke. Although the public generally associates carcinogenicity with synthetic chemicals, it is equally likely to arise from both natural and synthetic substances. Carcinogens are not necessarily immediately toxic; thus, their effect can be insidious. Carcinogens, as mentioned, are agents in the environment capable of contributing to cancer growth. Carcinogens can be categorized into two different types: activation-dependent and activation-independent, and each nature impacts the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nostoc
''Nostoc'', also known as star jelly, troll’s butter, spit of moon, fallen star, witch's butter (not to be confused with the fungi commonly known as witches' butter), and witch’s jelly, is the most common genus of cyanobacteria found in various environments that may form colonies composed of filaments of moniliform cells in a gelatinous sheath of polysaccharides. ''Nostoc'' is a genus of photosynthetic, Gram-negative cyanobacteria that can be found in both terrestrial and aquatic environments. It may also grow symbiotically within the tissues of plants, providing nitrogen to its host through the action of terminally differentiated cells known as heterocysts. ''Nostoc'' is a genus that includes many species that are diverse in morphology, habitat distribution, and ecological function. ''Nostoc'' can be found in soil, on moist rocks, at the bottom of lakes and springs, and rarely in marine habitats. It may also be found in terrestrial temperate, desert, tropical, or polar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fra-1
Fos-related antigen 1 (FRA1) is a protein that in humans is encoded by the ''FOSL1'' gene. Function The Fos gene family consists of 4 members: c-Fos, FOSB, FOSL1, and FOSL2. These genes encode leucine zipper proteins that can dimerize with proteins of the JUN family, thereby forming the transcription factor complex AP-1. As such, the FOS proteins have been implicated as regulators of cell proliferation, differentiation, and transformation. Interactions FOSL1 has been shown to interact with USF1 (human gene) and C-jun. See also * AP-1 (transcription factor) Activator protein 1 (AP-1) is a transcription factor that regulates gene expression in response to a variety of stimuli, including cytokines, growth factors, stress, and bacterial and viral infections. AP-1 controls a number of cellular proces ... References Further reading * * * * * * * * * * * * * * * * External links * * Transcription factors {{gene-11-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C-fos
Protein c-Fos is a proto-oncogene that is the human homolog of the retroviral oncogene v-fos. It is encoded in humans by the ''FOS'' gene. It was first discovered in rat fibroblasts as the transforming gene of the FBJ MSV (Finkel–Biskis–Jinkins murine osteogenic sarcoma virus) (Curran and Tech, 1982). It is a part of a bigger Fos family of transcription factors which includes c-Fos, FosB, Fra-1 and Fra-2. It has been mapped to chromosome region 14q21→q31. c-Fos encodes a 62 kDa protein, which forms heterodimer with c-jun (part of Jun family of transcription factors), resulting in the formation of AP-1 (Activator Protein-1) complex which binds DNA at AP-1 specific sites at the promoter and enhancer regions of target genes and converts extracellular signals into changes of gene expression. It plays an important role in many cellular functions and has been found to be overexpressed in a variety of cancers. Structure and function c-Fos is a 380 amino acid protein with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C-jun
Transcription factor Jun is a protein that in humans is encoded by the ''JUN'' gene. c-Jun, in combination with protein c-Fos, forms the AP-1 early response transcription factor. It was first identified as the Fos-binding protein p39 and only later rediscovered as the product of the JUN gene. c-jun was the first oncogenic transcription factor discovered. The proto-oncogene c-Jun is the cellular homolog of the viral oncoprotein v-jun (). The viral homolog v-jun was discovered in avian sarcoma virus 17 and was named for ''ju-nana'', the Japanese word for 17. The human JUN encodes a protein that is highly similar to the viral protein, which interacts directly with specific target DNA sequences to regulate gene expression. This gene is intronless and is mapped to 1p32-p31, a chromosomal region involved in both translocations and deletions in human malignancies. Function Regulation Both Jun and its dimerization partners in AP-1 formation are subject to regulation by diverse e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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