Biomaterial Database

RNA synthesis and processing reactions in a subcellular system from mouse L cells. 1982

K P Schäfer

A subcellular system from mouse L-cells has been used to study RNA synthesis and processing in vitro. The nuclei in this system incorporate nucleoside triphosphates into RNA with high yield for more than 120 min. The capacity for RNA synthesis is stable for extended periods at 4 degrees C. All three RNA polymerases contribute to the overall synthetic activity as shown by differential inhibition with alpha-amanitin. The in vitro labeled RNA contains about 15% of polyadenylated RNA. The non-polyadenylated RNA shows molecules in the range of larger than 20 S down to 4-5 S. The polyadenylated RNA exhibits mainly transcripts around 18 S and below 8 S. Methylation of nucleoside bases and the ribose 2'-OH group including 5'-caps is performed in vitro as well. Base methylation and 5'-cap methylation are partially sensitive to alpha-amanitin. 28% of the methyl groups are found in polyadenylated RNA being distributed throughout molecules of all sizes. The methylated non-polyadenylated RNA shows peaks at 45 S, around 28 S and 18 S, and a very prominent low-molecular weight RNA peak. Addition of the poly(A) tract to RNA molecules in vitro is revealed by the presence of [3H]-uridine-labeled polyadenylated RNA. The poly(A) tract was isolated and analyzed on polyacrylamide gels. Its maximum length coincides with an in vivo poly(A) marker indicating the addition of about 150-200 nucleotides. Poly(A) addition is possible on pre-existing RNA chains, preferably on 3'-oligo(A) tracts. This process is insensitive to alpha-amanitin. In addition, the specificity of polyadenylation may be relaxed since incorporation of [3H]UTP into polyadenylated RNA is only reduced to about 50% under conditions (1 microgram alpha-amanitin/ml) where RNA polymerase II is inhibited. A small fraction of the in vitro labeled RNA binds to polysomes which can be recovered from the cytoplasm adhering to the nuclei. This RNA contains poly(A) and is enriched in base methylations and 5' end caps. It can be dissociated from the polysomes by EDTA. It is likely to be in vitro labeled and maturated mRNA.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D007739	L Cells	A cultured line of C3H mouse FIBROBLASTS that do not adhere to one another and do not express CADHERINS.	Earle's Strain L Cells,L Cell Line,L Cells (Cell Line),L-Cell Line,L-Cells,L-Cells, Cell Line,L929 Cell Line,L929 Cells,NCTC Clone 929 Cells,NCTC Clone 929 of Strain L Cells,Strain L Cells,Cell Line L-Cell,Cell Line L-Cells,Cell Line, L,Cell Line, L929,Cell Lines, L,Cell, L,Cell, L (Cell Line),Cell, L929,Cell, Strain L,Cells, L,Cells, L (Cell Line),Cells, L929,Cells, Strain L,L Cell,L Cell (Cell Line),L Cell Lines,L Cell, Strain,L Cells, Cell Line,L Cells, Strain,L-Cell,L-Cell Lines,L-Cell, Cell Line,L929 Cell,Strain L Cell
D011061	Poly A	A group of adenine ribonucleotides in which the phosphate residues of each adenine ribonucleotide act as bridges in forming diester linkages between the ribose moieties.	Adenine Polynucleotides,Polyadenylic Acids,Poly(rA),Polynucleotides, Adenine
D011132	Polyribosomes	A multiribosomal structure representing a linear array of RIBOSOMES held together by messenger RNA; (RNA, MESSENGER); They represent the active complexes in cellular protein synthesis and are able to incorporate amino acids into polypeptides both in vivo and in vitro. (From Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)	Polysomes,Polyribosome,Polysome
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
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
D012265	Ribonucleotides	Nucleotides in which the purine or pyrimidine base is combined with ribose. (Dorland, 28th ed)	Ribonucleoside Phosphates,Ribonucleotide,Phosphates, Ribonucleoside
D012313	RNA	A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)	RNA, Non-Polyadenylated,Ribonucleic Acid,Gene Products, RNA,Non-Polyadenylated RNA,Acid, Ribonucleic,Non Polyadenylated RNA,RNA Gene Products,RNA, Non Polyadenylated
D012333	RNA, Messenger	RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.	Messenger RNA,Messenger RNA, Polyadenylated,Poly(A) Tail,Poly(A)+ RNA,Poly(A)+ mRNA,RNA, Messenger, Polyadenylated,RNA, Polyadenylated,mRNA,mRNA, Non-Polyadenylated,mRNA, Polyadenylated,Non-Polyadenylated mRNA,Poly(A) RNA,Polyadenylated mRNA,Non Polyadenylated mRNA,Polyadenylated Messenger RNA,Polyadenylated RNA,RNA, Polyadenylated Messenger,mRNA, Non Polyadenylated
D014158	Transcription, Genetic	The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.	Genetic Transcription