A Drosophila derailed homolog, doughnut, expressed in invaginating cells during embryogenesis.

TitleA Drosophila derailed homolog, doughnut, expressed in invaginating cells during embryogenesis.
Publication TypeJournal Article
Year of Publication1999
AuthorsSavant-Bhonsale S, Friese M, McCoon P, Montell DJ
Date Published1999 Apr 29
KeywordsAmino Acid Sequence, Animals, Blotting, Northern, Blotting, Southern, Cell Line, Drosophila, Drosophila Proteins, Gene Expression Regulation, Developmental, Insect Proteins, Molecular Sequence Data, Protein-Tyrosine Kinases, Sequence Homology, Amino Acid

<p>Members of the RYK family of receptors are homologous to tyrosine kinases but do not exhibit kinase activity in vitro. We describe a new member of this family in Drosophila, which we call Doughnut (DNT). The protein product was found to be 70% identical to the Drosophila Derailed (DRL) protein and 35-40% identical to the mammalian RYK proteins. During Drosophila embryogenesis, DNT was found to be expressed in a highly dynamic pattern, including many invaginating cells. Many aspects of the expression pattern resembled that of unpaired, a gene that encodes a secreted protein that stimulates the Drosophila JAK/STAT signaling pathway. RYK proteins contain amino acid substitutions at residues that are highly conserved amongst proteins that exhibit kinase activity. Therefore, it has been unclear whether RYK family members are catalytically active or, if they are not, how they might transduce a signal. When expressed in cell culture DNT became phosphorylated on tyrosine, as did a mutant form of the receptor, containing an arginine residue in place of lysine within the predicted nucleotide binding site. These results suggest that DNT associates with a catalytically active kinase, but may not be capable of autophosphorylation.</p>

Alternate JournalGene
PubMed ID10231580
Grant ListR01 AG063907 / AG / NIA NIH HHS / United States