Different forms of soluble cytoplasmic mRNA binding proteins and particles in Xenopus laevis oocytes and embryos

Journal Article · Tue Jan 01 04:00:00 EST 1991 · Journal of Cell Biology; (USA)

DOI:https://doi.org/10.1083/jcb.112.1.1· OSTI ID:5984745

Murray, M T; Krohne, G; Franke, W W ^[1]

---

1. Institute of Cell and Tumor Biology, Heidelberg (Germany, F.R.)

To gain insight into the mechanisms involved in the formation of maternally stored mRNPs during Xenopus laevis development, we searched for soluble cytoplasmic proteins of the oocyte that are able to selectively bind mRNAs, using as substrate radiolabeled mRNA. In vitro mRNP assembly in solution was followed by UV-cross-linking and RNase digestion, resulting in covalent tagging of polypeptides by nucleotide transfer. Five polypeptides of approximately 54, 56 60, 70, and 100 kD (p54, p56, p60, p70, and p100) have been found to selectively bind mRNA and assemble into mRNPs. These polypeptides, which correspond to previously described native mRNP components, occur in three different particle classes of approximately 4.5S, approximately 6S, and approximately 15S, as also determined by their reactions with antibodies against p54 and p56. Whereas the approximately 4.5S class contains p42, p60, and p70, probably each in the form of individual molecules or small complexes, the approximately 6S particles appears to consist only of p54 and p56, which occur in a near-stoichiometric ratio suggestive of a heterodimer complex. The approximately 15S particles contain, in addition to p54 and p56, p60 and p100 and this is the single occurring form of RNA-binding p100. We have also observed changes in the in vitro mRNA binding properties of these polypeptides during oogenesis and early embryonic development, in relation to their phosphorylation state and to the activity of an approximately 15S particle-associated protein kinase, suggesting that these proteins are involved in the developmental translational regulation of maternal mRNAs.

• OSTI ID: 5984745
• Journal Information: Journal of Cell Biology; (USA), Journal Name: Journal of Cell Biology; (USA) Vol. 112:1; ISSN 0021-9525; ISSN JCLBA
• Country of Publication: United States
• Language: English

Related Subjects

560120* -- Radiation Effects on Biochemicals
Cells
& Tissue Culture
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMPHIBIANS
ANIMALS
AQUATIC ORGANISMS
BIOCHEMICAL REACTION KINETICS
BIOSYNTHESIS
CELL CONSTITUENTS
CHEMICAL REACTIONS
CROSS-LINKING
CYTOPLASM
ELECTROMAGNETIC RADIATION
EMBRYOS
ENZYMES
ESTERASES
FROGS
GERM CELLS
HYDROLASES
KINETICS
MESSENGER-RNA
NUCLEIC ACIDS
NUCLEOPROTEINS
ONTOGENESIS
OOCYTES
ORGANIC COMPOUNDS
PEPTIDES
PHOSPHODIESTERASES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHORYLATION
PHOSPHOTRANSFERASES
POLYMERIZATION
POLYPEPTIDES
PROTEINS
RADIATIONS
REACTION KINETICS
RNA
RNA-ASE
SYNTHESIS
TRANSFERASES
ULTRAVIOLET RADIATION
VERTEBRATES