Regulating Translation of Maternal Messages: Multiple Repression Mechanisms

The dowry of mRNAs and proteins that mothers provide their progeny as part of a common developmental strategy to permit rapid embryogenesis necessitates precise translational regulation of the deposited mRNAs. Recent studies with Drosophila uncovered diverse mechanisms to control translation of the transcripts for genes that control the cell cycle and embryonic patterning. The newly delineated mechanisms include: alternative ways to disrupt eIF4E action and the formation of the preinitiation complex b y the eIF4E homologous protein, d4EHP; recruitment of the deadenylase complex by the SMAUG and PUMILIO proteins; both poly(A)-dependent and -independent promotion of translation by the PNG kinase complex; and 5' cap-independent translational regulation b y BRUNO.