Biomaterial Database

Characterization and levels of the RNA polymerases during the embryogenesis of Artemia salina. 1976

J Renart, and J Sebastian

Dormant embryos at the gastrula stage of Artemia salina contain three DNA-dependent RNA polymerases: I, II, and III. The enzymes are solubilized from whole embryos and they are separated by chromatography on DEAE Sephadex. The ratio of activities with native and denatured DNA at the optimal salt concentrations is 3.5 for RNA polymerase I, 0.1 for RNA polymerase II and 1.0 for RNA polymerase III.Mn(i2+) is more efficient than Mg(2+) for the three enzymes. RNA polymerase II is 50% inhibited by 5 ng/ml of alpha-amanitin while RNA polymerases I and III are 10% and 30% inhibited by 1 mg/ml. During the embryonic development there is am independent variation of the levels of the RNA polymerases. RNA polymerase I increases its specific activity 4-5-fold, RNA polymerase III increases 2-fold, and RNA polymerase II less than 2-fold. The increase in RNA polymerase activity may represent a mechanism to control the rate of synthesis of RNA during the embryogenesis of A. salina.

UI	MeSH Term	Description	Entries
D003445	Crustacea	A large subphylum of mostly marine ARTHROPODS containing over 42,000 species. They include familiar arthropods such as lobsters (NEPHROPIDAE), crabs (BRACHYURA), shrimp (PENAEIDAE), and barnacles (THORACICA).	Ostracoda,Ostracods,Crustaceas,Ostracod,Ostracodas
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D000546	Amanitins	Cyclic peptides extracted from carpophores of various mushroom species. They are potent inhibitors of RNA polymerases in most eukaryotic species, blocking the production of mRNA and protein synthesis. These peptides are important in the study of transcription. Alpha-amanitin is the main toxin from the species Amanitia phalloides, poisonous if ingested by humans or animals.	Amanitin
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012293	Rifampin	A semisynthetic antibiotic produced from Streptomyces mediterranei. It has a broad antibacterial spectrum, including activity against several forms of Mycobacterium. In susceptible organisms it inhibits DNA-dependent RNA polymerase activity by forming a stable complex with the enzyme. It thus suppresses the initiation of RNA synthesis. Rifampin is bactericidal, and acts on both intracellular and extracellular organisms. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p1160)	Rifampicin,Benemycin,Rifadin,Rimactan,Rimactane,Tubocin