Phosphorylation of ribosomal proteins during meiotic saturation and following activation in starfish oocytes: Its relationship with changes of intracellular pH

Journal Article · Fri Jan 01 00:00:00 EST 1988 · Experimental Cell Research; (United States)

DOI:https://doi.org/10.1016/0014-4827(88)90143-7· OSTI ID:5393831

Peaucellier, G; Picard, A; Robert, J J ^[1]; Capony, J P; Labbe, J C ^[2]; Doree, M ^[3]

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1. Laboratoire Arago, Banysuls sur Mer (France)
2. INSERM, Montpellier (France) CNRS-CRBM, Montpellier (France)
3. Laboratoire Arago, Banyuls sur Mer (France) INSERM, Montpellier (France) CNRS-CRBM, Montpellier (France)

An increased phosphorylation of ribosomal protein S6 has been shown to be correlated with an increase of intracellular pH (pH{sub i}) and with stimulation of protein synthesis in many systems. In this research changes in ribosome phosphorylation following hormone-induced meiotic maturation and fertilization or activation by ionophore A23187 were investigated in starfish oocytes. The hormone was found to stimulate the phosphorylation on serine residues of an M{sub r} 31,000 protein identified as S6, as well as that of an acidic M{sub r} 47,000 protein, presumably S1, on threonine residues. Phosphorylation of ribosomes was an early consequence of hormonal stimulation and did not decrease after completion of meiotic maturation. Fertilization or activation by ionophore of prophase-arrested oocytes also stimulated ribosome phosphorylation. The pH{sub i} did not change before germinal vesicle breakdown (GVBD) following hormone addition, but it increased before first polar body emission. It also increased following fertilization or activation by ionophore or the microinjection of Ca-EGTA. Phosphorylation of S6 was still observed following fertilization or induction of maturation when pH{sub i} was decreased by external application of acetate, a treatment which suppressed the emission of polar bodies. Protein synthesis increased in prophase-arrested oocytes after fertilization or activation.

• OSTI ID: 5393831
• Journal Information: Experimental Cell Research; (United States), Vol. 174:1; ISSN 0014-4827
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
NUCLEOPROTEINS
AUTORADIOGRAPHY
OOCYTES
MEIOSIS
PH VALUE
DOSE-RESPONSE RELATIONSHIPS
ARGININE
BIOSYNTHESIS
CARBON 14 COMPOUNDS
ECHINODERMS
PHOSPHORYLATION
RIBOSOMES
AMINO ACIDS
ANIMALS
AQUATIC ORGANISMS
CARBON COMPOUNDS
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CELL DIVISION
CHEMICAL REACTIONS
GERM CELLS
INVERTEBRATES
LABELLED COMPOUNDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PROTEINS
SYNTHESIS
550201* - Biochemistry- Tracer Techniques