First published online November 11, 2004
Development 131, 2303e (2004)
© The Company of Biologists Limited
Locating bicoid: step by step
Par-1, a Ser/Thr kinase, is required for cell polarisation in many
organisms. In Drosophila oogenesis, for example, Par-1 is involved in
several polarisation events, including the localisation of the anterior
determinant bicoid mRNA. Riechmann and Ephrussi now report that Par-1
regulates the localisation of bicoid mRNA by phosphorylating
Exuperantia (Exu; see p.
5897). They identify
Exu, a mediator of bicoid mRNA localisation, as a phosphorylation
target of Par-1 in a genome-wide, gel-based screen and describe two motifs in
Exu that are phosphorylated by Par-1. Mutation of these motifs abolishes
bicoid mRNA localisation in mid-oogenesis, but a proportion of the
oocytes subsequently recover from these bicoid mRNA localisation
defects, indicating that the requirement for Exu phosphorylation becomes less
stringent as oogenesis proceeds. Finally, the researchers propose a multi-step
model for bicoid mRNA localisation in which redundant mechanisms
ensure its anterior accumulation.
Related articles in Development:
- Par-1 regulates bicoid mRNA localisation by phosphorylating Exuperantia
- Veit Riechmann and Anne Ephrussi
Development 2004 131: 5897-5907.
[Abstract]
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