INVESTIGADORES
RIVERA-POMAR Rolando
artículos
Título:
A similar mechanism of translation for reaper and heat shock protein 70 mRNAs in Drosophila embryos
Autor/es:
HERNÁNDEZ GRECO,; VAZQUEZ-PIANZOLA, PAULA; SIERRA JM,; RIVERA POMAR R
Revista:
RNA (NEW YORK, N.Y.)
Referencias:
Año: 2004 vol. 10 p. 1783 - 1797
ISSN:
1355-8382
Resumen:
Translation is a sensitive regulatory step during cellular stress and
the apoptosis response. Under such conditions, cap-dependent
translation is reduced and internal ribosome entry site
(IRES)-dependent translation plays a major role. However, many aspects
of how mRNAs are translated under stress remain to be elucidated. Here
we report that reaper mRNA, a pro-apoptotic gene from Drosophila
melanogaster, is translated in a cap-independent manner. In Drosophila
mutant embryos devoid of the eukaryotic initiation factor 4E (eIF4E),
reaper transcription is induced and apoptosis proceeds. In vitro
translation experiments using wild-type and eIF4E mutant embryonic
extracts show that reporter mRNA bearing reaper 5' untranslated region
(UTR) is effectively translated in a cap-independent manner. The 5'UTR
of reaper exhibits a high degree of similarity with that of Drosophila
heat shock protein 70 mRNA, and both display IRES activity. Studies of
mRNA association to polysomes in embryos indicate that both reaper and
heat shock protein 70 mRNAs are recruited to polysomes under apoptosis
or thermal stress. Our data suggest that heat shock protein 70 and
reaper, two antagonizing factors in apoptosis, use a similar mechanism
for protein synthesis.