Mancebo, R., Zhou, X., Shillinglaw, W., Henzel, W. and Macdonald, P.M. (2001)
BSF binds specifically to the bicoid mRNA and contributes to its stabilization.
Molecular and Cellular Biology 21, 3462-3471.
Abstract
The early stages of Drosophila development rely extensively on post-transcriptional forms of gene regulation. Deployment of the anterior body patterning morphogen, the Bicoid protein, requires both localization and translational regulation of the maternal bicoid mRNA. Here we provide evidence that the bicoid mRNA is also selectively stabilized during oogenesis. We identify and isolate a protein, BSF, that binds specifically to IV/V RNA, a minimal form of the bicoid mRNA 3' UTR that supports a normal program of mRNA localization during oogenesis. Mutations that disrupt the BSF binding site in IV/V RNA or substantially reduce the level of BSF protein each lead to reduction in IV/V RNA levels, indicating a role for BSF in RNA stabilization. The BSF protein is novel and lacks any of the characterized RNA binding motifs. However, BSF does includes multiple copies of the PPR motif, whose function is unknown but appears in other proteins with roles in RNA metabolism.