Biomaterial Database

Role of DNA-dependent RNA polymerase 3 in the transcription of the tRNA and 5S RNA genes. 1974

R Weinmann, and R G Roeder

Mouse myeloma cells have previously been shown (L. B. Schwartz, V. E. F. Sklar, J. A. Jaehning, R. Weinmann & R. G. Roeder, submitted for publication) to contain two chromatographically distinct forms of RNA polymerase III (designated III(A) and III(B)). The enzymes are unaffected by low alpha-amanitin concentrations which completely inhibit RNA polymerase II, but they exhibit characteristic inhibition curves (identical for III(A) and III(B)) at higher toxin concentrations. RNA polymerase I was unaffected at all alpha-amanitin concentrations tested. Myeloma RNA polymerases II, III(A), and III(B) appear to be inhibited by the same mechanism, since the toxin rapidly blocks chain elongation by each enzyme. The characteristic alpha-amanitin sensitivity of RNA polymerase III has been employed in studies of the function(s) of the class III RNA polymerases. Isolated myeloma nuclei and nucleoli contińue to synthesize RNA via the endogenous RNA polymerases when incubated in vitro. With nuclei, newly synthesized 4S precursor (pre-4S) and 5S RNA species were detected by electrophoretic analysis either of the total nuclear RNA or of the RNA released into the supernatant during incubation. The synthesis of both pre-4S and 5S RNA species was inhibited by alpha-amanitin, but only at high concentrations; and the alpha-amanitin inhibition curves for these RNAs were identical to those obtained for solubilized RNA polymerases III(A) and III(B). In control experiments it was shown that the endogenous RNA polymerase II activity of isolated nuclei was inhibited by alpha-amanitin concentrations similar to those required to inhibit purified enzyme II. However, 40-50% of the endogenous activity of nuclei and 100% of the endogenous activity of purified nucleoli was completely resistant to the high alpha-amanitin concentrations necessary to inhibit the RNA polymerase III activities. These experiments rule out nonspecific inhibitory effects in the endogenous systems. These results unequivocally demonstrate the role of RNA polymerase III (III(A) and/or III(B)) in the synthesis of (pre) 4S RNAs and a 5S RNA species.

UI	MeSH Term	Description	Entries
D009101	Multiple Myeloma	A malignancy of mature PLASMA CELLS engaging in monoclonal immunoglobulin production. It is characterized by hyperglobulinemia, excess Bence-Jones proteins (free monoclonal IMMUNOGLOBULIN LIGHT CHAINS) in the urine, skeletal destruction, bone pain, and fractures. Other features include ANEMIA; HYPERCALCEMIA; and RENAL INSUFFICIENCY.	Myeloma, Plasma-Cell,Kahler Disease,Myeloma, Multiple,Myeloma-Multiple,Myelomatosis,Plasma Cell Myeloma,Cell Myeloma, Plasma,Cell Myelomas, Plasma,Disease, Kahler,Multiple Myelomas,Myeloma Multiple,Myeloma, Plasma Cell,Myeloma-Multiples,Myelomas, Multiple,Myelomas, Plasma Cell,Myelomas, Plasma-Cell,Myelomatoses,Plasma Cell Myelomas,Plasma-Cell Myeloma,Plasma-Cell Myelomas
D009183	Mycotoxins	Toxic compounds produced by FUNGI.	Fungal Toxins,Mycotoxin,Toxins, Fungal
D002466	Cell Nucleolus	Within most types of eukaryotic CELL NUCLEUS, a distinct region, not delimited by a membrane, in which some species of rRNA (RNA, RIBOSOMAL) are synthesized and assembled into ribonucleoprotein subunits of ribosomes. In the nucleolus rRNA is transcribed from a nucleolar organizer, i.e., a group of tandemly repeated chromosomal genes which encode rRNA and which are transcribed by RNA polymerase I. (Singleton & Sainsbury, Dictionary of Microbiology & Molecular Biology, 2d ed)	Plasmosome,Cell Nucleoli,Nucleoli, Cell,Nucleolus, Cell,Plasmosomes
D002467	Cell Nucleus	Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	Cell Nuclei,Nuclei, Cell,Nucleus, Cell
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
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
D005796	Genes	A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.	Cistron,Gene,Genetic Materials,Cistrons,Genetic Material,Material, Genetic,Materials, Genetic
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
D012321	DNA-Directed RNA Polymerases	Enzymes that catalyze DNA template-directed extension of the 3'-end of an RNA strand one nucleotide at a time. They can initiate a chain de novo. In eukaryotes, three forms of the enzyme have been distinguished on the basis of sensitivity to alpha-amanitin, and the type of RNA synthesized. (From Enzyme Nomenclature, 1992).	DNA-Dependent RNA Polymerases,RNA Polymerases,Transcriptases,DNA-Directed RNA Polymerase,RNA Polymerase,Transcriptase,DNA Dependent RNA Polymerases,DNA Directed RNA Polymerase,DNA Directed RNA Polymerases,Polymerase, DNA-Directed RNA,Polymerase, RNA,Polymerases, DNA-Dependent RNA,Polymerases, DNA-Directed RNA,Polymerases, RNA,RNA Polymerase, DNA-Directed,RNA Polymerases, DNA-Dependent,RNA Polymerases, DNA-Directed
D012334	RNA, Neoplasm	RNA present in neoplastic tissue.	Neoplasm RNA