title: Gprk2 adjusts Fog signaling to organize cell movements in Drosophila gastrulation.
abstract: Gastrulation of Drosophila melanogaster proceeds through sequential cell movements: ventral mesodermal (VM) cells are induced by secreted Fog protein to constrict their apical surfaces to form the ventral furrow, and subsequently lateral mesodermal (LM) cells involute toward the furrow. How these cell movements are organized remains elusive. Here, we observed that LM cells extended apical protrusions and then underwent accelerated involution movement, confirming that VM and LM cells display distinct cell morphologies and movements. In a mutant for the GPCR kinase Gprk2, apical constriction was expanded to all mesodermal cells and the involution movement was abolished. In addition, the mesodermal cells halted apical constriction prematurely in accordance with the aberrant accumulation of Myosin II. Epistasis analyses revealed that the Gprk2 mutant phenotypes were dependent on the fog gene. Overexpression of Gprk2 suppressed the effects of excess Cta, a downstream component of Fog signaling. Based on these findings, we propose that Gprk2 attenuates and tunes Fog-Cta signaling to prevent apical constriction in LM cells and to support appropriate apical constriction in VM cells. Thus, the two distinct cell movements in mesoderm invagination are not predetermined, but rather are organized by the adjustment of cell signaling.
authors.affiliation: Department of Developmental Genetics, National Institute of Genetics, Yata 1111, Mishima 411-8540, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Fuse
authors.forename: Fengwei
authors.initials: F
authors.lastname: Yu
authors.forename: Susumu
authors.initials: S
authors.lastname: Hirose
mesh_terms: D000818:Animals; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D002450:Cell Communication; D002465:Cell Movement; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D054769:G-Protein-Coupled Receptor Kinase 2 / Q000235:genetics / Q000378:metabolism*; D054262:Gastrulation; D018507:Gene Expression Regulation, Developmental; D008648:Mesoderm / Q000166:cytology / Q000378:metabolism; D010641:Phenotype; D015398:Signal Transduction
chemical_list: D029721:Drosophila Proteins; C508614:FOG protein, Drosophila; D054769:G-Protein-Coupled Receptor Kinase 2; C496574:Gprk2 protein, Drosophila; D000252:Calcium-Transporting ATPases
keywords: Drosophila; Gastrulation; Gprk2