Binding of a phosphoprotein to the 3' untranslated region of the mouse protamine 2 mRNA temporally represses its translation.
Mol Cell Biol
; 13(10): 6547-57, 1993 Oct.
Article
em En
| MEDLINE
| ID: mdl-8413253
ABSTRACT
The synthesis of the protamines, the predominant nuclear proteins of mammalian spermatozoa, is regulated during germ cell development by mRNA storage for about 7 days in the cytoplasm of differentiating spermatids. Two highly conserved sequences, the Y and H elements present in the 3' untranslated regions (UTRs) of all known mammalian protamine mRNAs, form RNA-protein complexes and specifically bind a protein of 18 kDa. Here, we show that translation of fusion mRNAs was markedly repressed in reticulocyte lysates supplemented with a mouse testis extract enriched for the 18-kDa protein when the mRNAs contained the 3' UTR of mouse protamine 2 (mP2) or the Y and H elements of mP2. No significant decrease was seen when the fusion mRNAs contained the 3' UTR of human growth hormone. The 18-kDa protein is developmentally regulated in male germ cells, requires phosphorylation for RNA binding, and is found in the ribonucleoprotein particle fractions of a testicular postmitochondrial supernatant. We propose that a phosphorylated 18-kDa protein plays a primary role in repressing translation of mP2 mRNA by interaction with the highly conserved Y and H elements. At a later stage of male gamete differentiation, the 18-kDa protein no longer binds to the mRNA, likely as a result of dephosphorylation, enabling the protamine mRNA to be translated.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fosfoproteínas
/
Biossíntese de Proteínas
/
Protaminas
Limite:
Animals
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Humans
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Male
Idioma:
En
Revista:
Mol Cell Biol
Ano de publicação:
1993
Tipo de documento:
Article