Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Nucleic Acids Res
1997 Jan 15;252:395-402. doi: 10.1093/nar/25.2.395.
Show Gene links
Show Anatomy links
Cap-independent translation initiation in Xenopus oocytes.
Keiper BD
,
Rhoads RE
.
???displayArticle.abstract???
Eukaryotic cellular mRNAs contain a cap at their 5'-ends, but some viral and cellular mRNAs bypass the cap-dependent mechanism of translation initiation in favor of internal entry of ribosomes at specific RNA sequences. Cap-dependent initiation requires intact initiation factor eIF4G (formerly eIF-4gamma, eIF-4Fgamma or p220), whereas internal initiation can proceed with eIF4G cleaved by picornaviral 2A or L proteases. Injection of recombinant coxsackievirus B4 protease 2A into Xenopus oocytes led to complete cleavage of endogenous eIF4G, but protein synthesis decreased by only 35%. Co-injection of edeine reduced synthesis by >90%, indicating that eIF4G-independent synthesis involved ongoing initiation. The spectrum of endogenous proteins synthesized was very similar in the presence or absence of intact eIF4G. Translation of exogenous rabbit globin mRNA, by contrast, was drastically inhibited by eIF4G cleavage. The N-terminal cleavage product of eIF4G (cpN), which binds eIF4E, was completely degraded within 6-12 h, while the C-terminal cleavage product (cpC), which binds to eIF3 and eIF4A, was more stable over the same period. Thus, translation initiation of most endogenous mRNAs inXenopusoocytes requires no eIF4G, or perhaps only cpC, suggesting a cap-independent mechanism.
Aldabe,
Expression of poliovirus 2Apro in mammalian cells: effects on translation.
1995, Pubmed
Aldabe,
Expression of poliovirus 2Apro in mammalian cells: effects on translation.
1995,
Pubmed
Anthony,
Analysis of 40 S and 80 S complexes with mRNA as measured by sucrose density gradients and primer extension inhibition.
1992,
Pubmed
Asselbergs,
Cap analogues do not inhibit mRNA translation in Xenopus laevis oocytes.
1978,
Pubmed
,
Xenbase
Asselbergs,
Messenger RNA competition in living Xenopus oocytes.
1979,
Pubmed
,
Xenbase
Audet,
Eukaryotic initiation factor 4A stimulates translation in microinjected Xenopus oocytes.
1987,
Pubmed
,
Xenbase
Barco,
Poliovirus 2Apro expression inhibits growth of yeast cells.
1995,
Pubmed
Bernstein,
Poliovirus mutant that does not selectively inhibit host cell protein synthesis.
1985,
Pubmed
Bonneau,
Effect of viral infection on host protein synthesis and mRNA association with the cytoplasmic cytoskeletal structure.
1985,
Pubmed
Bonneau,
Proteolysis of the p220 component of the cap-binding protein complex is not sufficient for complete inhibition of host cell protein synthesis after poliovirus infection.
1987,
Pubmed
Borman,
Picornavirus internal ribosome entry segments: comparison of translation efficiency and the requirements for optimal internal initiation of translation in vitro.
1995,
Pubmed
Bouvet,
A role for transcription and FRGY2 in masking maternal mRNA within Xenopus oocytes.
1994,
Pubmed
,
Xenbase
Braddock,
Intron-less RNA injected into the nucleus of Xenopus oocytes accesses a regulated translation control pathway.
1994,
Pubmed
,
Xenbase
Chu,
Inhibition of cell-free messenger ribonucleic acid translation by 7-methylguanosine 5'-triphosphate: effect of messenger ribonucleic acid concentration.
1980,
Pubmed
Drummond,
The effect of capping and polyadenylation on the stability, movement and translation of synthetic messenger RNAs in Xenopus oocytes.
1985,
Pubmed
,
Xenbase
Dworkin,
Functions of maternal mRNA in early development.
1990,
Pubmed
Dworkin,
Mobilization of specific maternal RNA species into polysomes after fertilization in Xenopus laevis.
1985,
Pubmed
,
Xenbase
Eppig,
Amino acid pools in developing oocytes of Xenopus laevis.
1972,
Pubmed
,
Xenbase
Etchison,
Inhibition of HeLa cell protein synthesis following poliovirus infection correlates with the proteolysis of a 220,000-dalton polypeptide associated with eucaryotic initiation factor 3 and a cap binding protein complex.
1982,
Pubmed
Gabrielli,
Requirement for Cdk2 in cytostatic factor-mediated metaphase II arrest.
1993,
Pubmed
,
Xenbase
Gan,
Internal initiation of translation directed by the 5'-untranslated region of the mRNA for eIF4G, a factor involved in the picornavirus-induced switch from cap-dependent to internal initiation.
1996,
Pubmed
Grifo,
New initiation factor activity required for globin mRNA translation.
1983,
Pubmed
Gurdon,
Use of frog eggs and oocytes for the study of messenger RNA and its translation in living cells.
1971,
Pubmed
,
Xenbase
Hambidge,
Translational enhancement of the poliovirus 5' noncoding region mediated by virus-encoded polypeptide 2A.
1992,
Pubmed
Herrera,
An altered ribosomal protein in an edeine-resistant mutant of Saccharomyces cerevisiae.
1986,
Pubmed
Hershey,
Translational control in mammalian cells.
1991,
Pubmed
Iizuka,
Cap-dependent and cap-independent translation by internal initiation of mRNAs in cell extracts prepared from Saccharomyces cerevisiae.
1994,
Pubmed
Irurzun,
Monensin and nigericin prevent the inhibition of host translation by poliovirus, without affecting p220 cleavage.
1995,
Pubmed
Jackson,
Internal initiation of translation in eukaryotes: the picornavirus paradigm and beyond.
1995,
Pubmed
Kay,
Xenopus laevis: Practical uses in cell and molecular biology. Injections of oocytes and embryos.
1991,
Pubmed
,
Xenbase
Keiper,
Nucleotide sequence and 40 S subunit assembly of Xenopus laevis ribosomal protein S22.
1990,
Pubmed
,
Xenbase
Kelso-Winemiller,
'Unmasking' of stored maternal mRNAs and the activation of protein synthesis at fertilization in sea urchins.
1991,
Pubmed
Kevil,
Translational enhancement of FGF-2 by eIF-4 factors, and alternate utilization of CUG and AUG codons for translation initiation.
1995,
Pubmed
Kozak,
Role of ATP in binding and migration of 40S ribosomal subunits.
1980,
Pubmed
Kuge,
Cytoplasmic 3' poly(A) addition induces 5' cap ribose methylation: implications for translational control of maternal mRNA.
1995,
Pubmed
,
Xenbase
Lacal,
Relationship between membrane integrity and the inhibition of host translation in virus-infected mammalian cells. Comparative studies between encephalomyocarditis virus and poliovirus.
1982,
Pubmed
Lamphear,
Mapping the cleavage site in protein synthesis initiation factor eIF-4 gamma of the 2A proteases from human Coxsackievirus and rhinovirus.
1993,
Pubmed
Lamphear,
Mapping of functional domains in eukaryotic protein synthesis initiation factor 4G (eIF4G) with picornaviral proteases. Implications for cap-dependent and cap-independent translational initiation.
1995,
Pubmed
Laskey,
Protein synthesis in oocytes of Xenopus laevis is not regulated by the supply of messenger RNA.
1977,
Pubmed
,
Xenbase
Lee,
Isolation and structural characterization of cap-binding proteins from poliovirus-infected HeLa cells.
1985,
Pubmed
Liebig,
Purification of two picornaviral 2A proteinases: interaction with eIF-4 gamma and influence on in vitro translation.
1993,
Pubmed
López-Rivas,
Cation content in poliovirus-infected HeLa cells.
1987,
Pubmed
Mader,
The translation initiation factor eIF-4E binds to a common motif shared by the translation factor eIF-4 gamma and the translational repressors 4E-binding proteins.
1995,
Pubmed
Moazed,
Interaction of antibiotics with functional sites in 16S ribosomal RNA.
,
Pubmed
Morley,
Hormone-induced meiotic maturation in Xenopus oocytes occurs independently of p70s6k activation and is associated with enhanced initiation factor (eIF)-4F phosphorylation and complex formation.
1995,
Pubmed
,
Xenbase
Mèndez,
Stimulation of protein synthesis, eukaryotic translation initiation factor 4E phosphorylation, and PHAS-I phosphorylation by insulin requires insulin receptor substrate 1 and phosphatidylinositol 3-kinase.
1996,
Pubmed
Nelson,
Regulation of mRNA entry into polysomes. Parameters affecting polysome size and the fraction of mRNA in polysomes.
1987,
Pubmed
O'Neill,
Inhibition of translation in cells infected with a poliovirus 2Apro mutant correlates with phosphorylation of the alpha subunit of eucaryotic initiation factor 2.
1989,
Pubmed
Ohlmann,
Proteolytic cleavage of initiation factor eIF-4 gamma in the reticulocyte lysate inhibits translation of capped mRNAs but enhances that of uncapped mRNAs.
1995,
Pubmed
Ohlmann,
The C-terminal domain of eukaryotic protein synthesis initiation factor (eIF) 4G is sufficient to support cap-independent translation in the absence of eIF4E.
1996,
Pubmed
Pérez,
Lack of direct correlation between p220 cleavage and the shut-off of host translation after poliovirus infection.
1992,
Pubmed
Rhoads,
Regulation of eukaryotic protein synthesis by initiation factors.
1993,
Pubmed
Rhoads,
Mechanism of action and regulation of protein synthesis initiation factor 4E: effects on mRNA discrimination, cellular growth rate, and oncogenesis.
1993,
Pubmed
Richter,
Translational control during early development.
1991,
Pubmed
,
Xenbase
Richter,
The mechanism for increased protein synthesis during Xenopus oocyte maturation.
1982,
Pubmed
,
Xenbase
Richter,
Differential capacity for translation and lack of competition between mRNAs that segregate to free and membrane-bound polysomes.
1981,
Pubmed
,
Xenbase
Richter,
Reversible inhibition of translation by Xenopus oocyte-specific proteins.
,
Pubmed
,
Xenbase
Rinker-Schaeffer,
Decreasing the level of translation initiation factor 4E with antisense RNA causes reversal of ras-mediated transformation and tumorigenesis of cloned rat embryo fibroblasts.
1993,
Pubmed
Rosenwald,
Elevated levels of cyclin D1 protein in response to increased expression of eukaryotic initiation factor 4E.
1993,
Pubmed
Schwemmle,
A 60-kDa protein from rabbit reticulocytes specifically recognizes the capped 5' end of beta-globin mRNA.
1991,
Pubmed
Shantz,
Overproduction of ornithine decarboxylase caused by relief of translational repression is associated with neoplastic transformation.
1994,
Pubmed
Skern,
Picornains 2A and 3C.
1994,
Pubmed
Smith,
Oogenesis and oocyte isolation.
1991,
Pubmed
,
Xenbase
Sommergruber,
2A proteinases of coxsackie- and rhinovirus cleave peptides derived from eIF-4 gamma via a common recognition motif.
1994,
Pubmed
Sonenberg,
Measures and countermeasures in the modulation of initiation factor activities by viruses.
1990,
Pubmed
Tahara,
Two forms of purified m7G-cap binding protein with different effects on capped mRNA translation in extracts of uninfected and poliovirus-infected HeLa cells.
1981,
Pubmed
Tarun,
A common function for mRNA 5' and 3' ends in translation initiation in yeast.
1995,
Pubmed
Whetter,
Low efficiency of the 5' nontranslated region of hepatitis A virus RNA in directing cap-independent translation in permissive monkey kidney cells.
1994,
Pubmed
Wormington,
Preparation of synthetic mRNAs and analyses of translational efficiency in microinjected Xenopus oocytes.
1991,
Pubmed
,
Xenbase
Yan,
Amino acid sequence of the human protein synthesis initiation factor eIF-4 gamma.
1992,
Pubmed
Ziegler,
Picornavirus 2A proteinase-mediated stimulation of internal initiation of translation is dependent on enzymatic activity and the cleavage products of cellular proteins.
1995,
Pubmed
