BMP signaling requires an inwardly rectifying K+ channel to pattern Drosophila wing. Giri Raj Dahal, Brandon Gassaway, Ben Kwok, Emily Bates. Chemistry and Biochemistry, Birgham Young University, Provo, UT.

   Mutations that disrupt the Inwardly rectifying K+ (Irk) channel Kir2.1 cause periodic paralysis, heart arrhythmias and dysmorphic features in humans. Morphological defects were also observed in mice and flies when a homologous channel is inhibited. Using Drosophila genetics we found the molecular mechanism that underlies the developmental phenotypes. We eliminated or reduced functional Irk2 channel in Drosophila wing and characterized the phenotypes, which are similar to Bone Morphogenetic Protein (BMP) signaling defects. We found that antagonizing Irk channels reduces BMP signaling and leads to wing defects. We found that Irk2 is necessary downstream of BMP transcription and upstream of phosphorylation of the BMP type 1 receptor in the signaling cascade. Our data demonstrate that developmental signaling cascades can sense membrane potential.