Biomaterial Database

The cap and poly(A) tail function synergistically to regulate mRNA translational efficiency. 1991

D R Gallie

Department of Biochemistry, University of California, Riverside 92521.

The cap structure and the poly(A) tail are important regulatory determinants in establishing the translational efficiency of a messenger RNA. Although the mechanism by which either determinant functions remains poorly characterized, the interaction between the poly(A) tail-poly(A)-binding protein complex and events occurring at the 5' terminus during translation initiation has been an intriguing possibility. In this report, the mutual dependence of the cap and the poly(A) tail was studied. Poly(A)+ and poly(A)- luciferase (Luc) mRNAs generated in vitro containing or lacking a cap were translated in vivo in tobacco protoplasts, Chinese hamster ovary cells, and yeast following delivery by electroporation. The poly(A) tail-mediated regulation of translational efficiency was wholly dependent on the cap for function. Moreover, cap function was enhanced over an order of magnitude by the presence of a poly(A) tail. The relative differences in stability between the mRNAs could not account for the synergism. The synergism between the cap and poly(A) tail was not observed in yeast cells in which active translation had been disrupted. In addition, the synergism was not observed in in vitro translation lysates. These data demonstrate that the cap and the poly(A) tail are interdependent for optimal function in vivo and suggest that communication between the two regulatory determinants may be important in establishing efficient translation.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008156	Luciferases	Enzymes that oxidize certain LUMINESCENT AGENTS to emit light (PHYSICAL LUMINESCENCE). The luciferases from different organisms have evolved differently so have different structures and substrates.	Luciferase
D010947	Plants, Toxic	Plants or plant parts which are harmful to man or other animals.	Plants, Poisonous,Plant, Poisonous,Plant, Toxic,Poisonous Plant,Poisonous Plants,Toxic Plant,Toxic Plants
D010957	Plasmids	Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.	Episomes,Episome,Plasmid
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
D011523	Protoplasts	The protoplasm and plasma membrane of plant, fungal, bacterial or archaeon cells without the CELL WALL.	Protoplast
D005786	Gene Expression Regulation	Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.	Gene Action Regulation,Regulation of Gene Expression,Expression Regulation, Gene,Regulation, Gene Action,Regulation, Gene Expression
D006224	Cricetinae	A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.	Cricetus,Hamsters,Hamster
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
D012315	RNA Caps	Nucleic acid structures found on the 5' end of eukaryotic cellular and viral messenger RNA and some heterogeneous nuclear RNAs. These structures, which are positively charged, protect the above specified RNAs at their termini against attack by phosphatases and other nucleases and promote mRNA function at the level of initiation of translation. Analogs of the RNA caps (RNA CAP ANALOGS), which lack the positive charge, inhibit the initiation of protein synthesis.	RNA Cap,5' Capped RNA,5' mRNA Cap Structure,Cap, RNA,Caps, RNA,RNA, 5' Capped