title: Heterotrimeric G proteins regulate a noncanonical function of septate junction proteins to maintain cardiac integrity in Drosophila.
abstract: The gene networks regulating heart morphology and cardiac integrity are largely unknown. We previously reported a role for the heterotrimeric G protein gamma subunit 1 (Ggamma1) in mediating cardial-pericardial cell adhesion in Drosophila. Here we show G-oalpha47A and Gbeta13F cooperate with Ggamma1 to maintain cardiac integrity. Cardial-pericardial cell adhesion also relies on the septate junction (SJ) proteins Neurexin-IV (Nrx-IV), Sinuous, Coracle, and Nervana2, which together function in a common pathway with Ggamma1. Furthermore, Ggamma1 signaling is required for proper SJ protein localization, and loss of at least one SJ protein, Nrx-IV, induces cardiac lumen collapse. These results are surprising because the embryonic heart lacks SJs and suggest that SJ proteins perform noncanonical functions to maintain cardiac integrity in Drosophila. Our findings unveil the components of a previously unrecognized network of genes that couple G protein signaling with structural constituents of the heart.
authors.affiliation: Department of Molecular Biology, University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX 75390-9148, USA.
authors.forename: Peng
authors.initials: P
authors.lastname: Yi
authors.forename: Aaron N
authors.initials: AN
authors.lastname: Johnson
authors.forename: Zhe
authors.initials: Z
authors.lastname: Han
authors.forename: Jiang
authors.initials: J
authors.lastname: Wu
authors.forename: Eric N
authors.initials: EN
authors.lastname: Olson
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D004331:Drosophila melanogaster / Q000196:embryology / Q000378:metabolism*; D053263:Gene Regulatory Networks; D006321:Heart / Q000033:anatomy & histology / Q000196:embryology; D020962:Heterotrimeric GTP-Binding Proteins / Q000378:metabolism*; D009024:Morphogenesis; D015398:Signal Transduction
chemical_list: D020962:Heterotrimeric GTP-Binding Proteins