Original research articleThe activity of the Drosophila Vestigial protein is modified by Scalloped-dependent phosphorylation

- Vestigial undergoes Scalloped-dependent phosphorylation at Serine 215.
- Phosphorylation of Vestigial has developmental consequences in disparate tissues.
- P38b is the kinase responsible for phosphorylation at Ser-215.
- Vestigial phosphorylation may separate proliferative and fate determination roles.

The Drosophila vestigial gene is required for proliferation and differentiation of the adult wing and for differentiation of larval and adult muscle identity. Vestigial is part of a multi-protein transcription factor complex, which includes Scalloped, a TEAD-class DNA binding protein. Binding Scalloped is necessary for translocation of Vestigial into the nucleus. We show that Vestigial is extensively post-translationally modified and at least one of these modifications is required for proper function during development. We have shown that there is p38-dependent phosphorylation of Serine 215 in the carboxyl-terminal region of Vestigial. Phosphorylation of Serine 215 occurs in the nucleus and requires the presence of Scalloped. Comparison of a phosphomimetic and non-phosphorylatable mutant forms of Vestigial shows differences in the ability to rescue the wing and muscle phenotypes associated with a null vestigial allele.