Sec61alpha is required for dorsal closure during Drosophila embryogenesis through its regulation of Dpp signaling.
During dorsal closure in Drosophila, signaling events in the dorsalmost row of epidermal cells (DME cells) direct the migration of lateral epidermal sheets towards the dorsal midline where they fuse to enclose the embryo. A Jun amino-terminal kinase (JNK) cascade in the DME cells induces the expression of Decapentaplegic (Dpp). Dpp signaling then regulates the cytoskeleton in the DME cells and amnioserosa to affect the cell shape changes necessary to complete dorsal closure. We identified a mutation in Sec61alpha that specifically perturbs dorsal closure. Sec61alpha encodes the main subunit of the translocon complex for co-translational import of proteins into the ER. JNK signaling is normal in Sec61alpha mutant embryos, but Dpp signaling is attenuated and the DME cells fail to maintain an actinomyosin cable as epithelial migration fails. Consistent with this model, dorsal closure is rescued in Sec61alpha mutant embryos by an activated form of the Dpp receptor Thick veins.
Wang
Xiaochen
X
Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, USA.
Ward
Robert E
RE
D000205:Actomyosin / Q000378:metabolism; D000483:Alleles; D000818:Animals; D002465:Cell Movement; D003599:Cytoskeleton / Q000378:metabolism; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D048670:MAP Kinase Kinase 4 / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D018613:Microscopy, Confocal / Q000379:methods; D009154:Mutation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism*; D000069816:SEC Translocation Channels; D015398:Signal Transduction
D029721:Drosophila Proteins; D008565:Membrane Proteins; D011956:Receptors, Cell Surface; D000069816:SEC Translocation Channels; C064196:dpp protein, Drosophila; D000205:Actomyosin; C090169:tkv protein, Drosophila; D017346:Protein Serine-Threonine Kinases; D048670:MAP Kinase Kinase 4