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E Piot

Publications and source records attributed to E Piot.

5 recordsLinked to original sources
PubMed1985

Initiation factor eIF2 associated with non-polysomal poly(A)-containing messenger ribonucleoproteins of cryptobiotic gastrulae of Artemia salina.

Non-polysomal poly(A)-containing mRNP of A. salina cryptobiotic embryos is separated in mRNP active in protein synthesis and in repressed mRNP by sucrose gradient centrifugation. In the translationally active fraction the presence of eukaryotic initiation factor 2 (eIF2) is demonstrated by electroblotting of sodium dodecylsulphate/polyacrylamide gels on nitrocellulose and anti-eIF2 antibody detection. mRNP proteins with Mr of 40 000 and 42 000 are identified as the alpha and beta subunits of eIF2. The repressed mRNP is devoid of eIF2 and is associated with an inhibitor ribonucleoprotein composed of a small 85 +/- 2-nucleotide-long RNA and a protein with Mr of 64 000. The latter ribonucleoprotein is a potent inhibitor of the translationally active mRNP.

Animals↗
PubMed1984

Identification and properties of the 38 000-Mr poly(A)-binding protein of non-polysomal messenger ribonucleoproteins of cryptobiotic gastrulae of Artemia salina.

The Mr-38 000 poly(A)-binding protein interacts with synthetic and natural RNA. A sequence-independent stoichiometry of one protein per 8 - 12 nucleotides is measured by filter binding and sucrose gradient centrifugation. Specificity for the poly(A) sequence is demonstrated from poly(A)/RNA mixing experiments. The poly(A)-binding protein has been identified as the helix-destabilizing protein HD40[Marvil, D. K., Nowak, L. and Szer, W. (1980) J. Biol. Chem. 255, 6466 - 6472] and is characterized by the existence of at least seven ionic species with a pI ranging from 9.2 to 6.6. Acidic ionic species are generated by phosphorylation with mRNP-associated protein kinase. Different ionic species are present on free mRNP and ribosomes-mRNP preinitiation complexes. The poly(A)-binding protein affects mRNA translation and (A)4 polyadenylation. The multifunctionality of the protein is discussed.

Animals↗
PubMed1982

The 38,000-Mr poly(A)-binding protein of non-polysomal messenger ribonucleoproteins of cryptobiotic gastrulae of Artemia salina.

The 38,000-Mr poly(A)-binding protein has been purified to near homogeneity from non-polysomal messenger ribonucleoprotein of Artemia salina [Slegers, H., De Herdt, E., and Kondo, M. (1981) Eur. J. Biochem. 117, 111-120]. The protein consists of approximately 357 amino acids and is characterized by a high glycine content of 22.5% and the presence of dimethylarginine. From polynucleotide-protein binding experiments a stoichiometry of 9-11 adenylate and 10-12 uridylate residues per protein molecule is calculated. The polypeptide is devoid of poly(A) polymerase and RNase activities. The poly(A)-binding protein and the helix-destabilizing protein HD40 [Marvil, D. K., Nowak, L., and Szer, W. (1980) J. Biol. Chem. 255, 6466-6472] have the same mobility in polyacrylamide/dodecylsulphate gel electrophoresis and exhibit a comparable amino acid composition and protein-polynucleotide stoichiometry. Based on the length of poly(A) sequences of mRNA and from protein-poly(A) binding experiments, a repetitive binding of the 38,000-Mr protein on the poly(A) sequence is demonstrated. The 38,000-Mr protein of cytoplasmic and membrane-bound non-polysomal messenger ribonucleoproteins is also compared.

Amino Acids↗
PubMed1979

Non-polyadenylated 22 s ribonucleoprotein particle is insensitive to translational inhibitor RNA of cryptobiotic gastrulae of Artemia salina.

A free cytoplasmic 22 S ribonucleoprotein particle exhibiting a major template activity in rabbit reticulocyte system has been identified in the cryptobiotic gastrulae of Artemia salina. This particle contains non-polyadenylated 9 S messenger RNA which codes primarily for a non-histone basic protein with an apparent molecular weight of 26 000 daltons. We have previously demonstrated the presence of a translational inhibitor RNA which is apparently responsible for transforming polyadenylated messenger (Slegers et al., FEBS Letters 80, 390-394, 1977). This inhibitor RNA was found to be completely ineffective on the template activity of non-polyadenylated 22 S messenger ribonucleoprotein, confirming the specificity of this regulatory RNA for polyadenylate sequences.

Animals↗