Taxonomic distribution of proteins containing DBB domains

The tree below includes only several representative species and genera. The complete taxonomic breakdown of all proteins containing DBB domains can be accessed here. Click the counts or percentage values to display the corresponding proteins.

A functional domain of Dof that is required for fibroblast growth factorsignaling.

Wilson R, Battersby A, Csiszar A, Vogelsang E, Leptin M
Mol Cell Biol. 2004; 24: 2263-76

Signal transduction by fibroblast growth factor (FGF) receptors in Drosophiladepends upon the intracellular protein Dof, which has been proposed to actdownstream of the receptors and upstream of Ras. Dof is the product of afast-evolving gene whose vertebrate homologs, BCAP and BANK, are involved insignaling downstream of the B-cell receptor. Mapping functional domains withinDof revealed that neither of its potential interaction motifs, the ankyrinrepeats and the coiled coil, is essential for the function of Dof. However, wehave identified a region within the N terminus of the protein with similarity to BCAP and BANK, which we refer to as the Dof, BCAP, and BANK (DBB) motif, that it is required for FGF-dependent signal transduction and is necessary for efficient interaction of Dof with the FGF receptor Heartless. In addition, we demonstratethat Dof is phosphorylated in the presence of an activated FGF receptor and that tyrosine residues could contribute to the function of the molecule.

Isolation of proteins that interact with the signal transduction molecule Dof andidentification of a functional domain conserved between Dof and vertebrate BCAP.

Battersby A, Csiszar A, Leptin M, Wilson R
J Mol Biol. 2003; 329: 479-93

Dof is a large molecule essential for signal transduction by the two FGFreceptors in Drosophila. It contains two ankyrin repeats and a coiled-coilregion, but has no other recognisable structural motif. Dof shares these featureswith its closest vertebrate relatives, the B-cell signalling molecules BCAP andBANK. In addition, this family of proteins shares a region of homology upstreamof the ankyrin repeats, which we call the Dof/BCAP/BANK (DBB) motif. We haveidentified 44 proteins that interact with Dof in a yeast two-hybrid screen. Theseinclude the Drosophila FGF-receptor Heartless and Dof itself. We show that theintegrity of the DBB motif is required both for Dof and for BCAP to form dimers. Analysis of the interactions between a set of deletion constructs of Dof and the panel of interactors suggests that Dof may adopt different conformations, with a folded conformation stabilized by interactions between the DBB motif and theC-terminal part of the protein.