title: Myosin light-chain phosphatase regulates basal actomyosin oscillations during morphogenesis.
abstract: Contractile actomyosin networks generate forces that drive tissue morphogenesis. Actomyosin contractility is controlled primarily by reversible phosphorylation of the myosin-II regulatory light chain through the action of myosin kinases and phosphatases. While the role of myosin light-chain kinase in regulating contractility during morphogenesis has been largely characterized, there is surprisingly little information on myosin light-chain phosphatase (MLCP) function in this context. Here, we use live imaging of Drosophila follicle cells combined with mathematical modelling to demonstrate that the MLCP subunit flapwing (flw) is a key regulator of basal myosin oscillations and cell contractions underlying egg chamber elongation. Flw expression decreases specifically on the basal side of follicle cells at the onset of contraction and flw controls the initiation and periodicity of basal actomyosin oscillations. Contrary to previous reports, basal F-actin pulsates similarly to myosin. Finally, we propose a quantitative model in which periodic basal actomyosin oscillations arise in a cell-autonomous fashion from intrinsic properties of motor assemblies.
authors.affiliation: Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide/CSIC/JA, Carretera de Utrera km 1, Sevilla 41013, Spain.
authors.forename: Andrea
authors.initials: A
authors.lastname: Valencia-Expósito
authors.affiliation: Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide/CSIC/JA, Carretera de Utrera km 1, Sevilla 41013, Spain.
authors.forename: Inna
authors.initials: I
authors.lastname: Grosheva
authors.affiliation: Departamento de Física de la Materia Condensada, Instituto de Ciencias de Materiales Nicolás Cabrera, Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid 28049, Spain.
authors.forename: David G
authors.initials: DG
authors.lastname: Míguez
authors.affiliation: Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide/CSIC/JA, Carretera de Utrera km 1, Sevilla 41013, Spain.
authors.forename: Acaimo
authors.initials: A
authors.lastname: González-Reyes
authors.affiliation: Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide/CSIC/JA, Carretera de Utrera km 1, Sevilla 41013, Spain.
authors.forename: María D
authors.initials: MD
authors.lastname: Martín-Bermudo
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism; D000205:Actomyosin / Q000235:genetics / Q000378:metabolism; D000818:Animals; D004330:Drosophila / Q000196:embryology* / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D008297:Male; D009024:Morphogenesis; D024462:Myosin Type II / Q000235:genetics / Q000378:metabolism*; D010063:Ovum / Q000254:growth & development / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism*
chemical_list: D000199:Actins; D029721:Drosophila Proteins; C495593:Sqh protein, Drosophila; D000205:Actomyosin; D010749:Phosphoprotein Phosphatases; C569978:flw protein, Drosophila; D024462:Myosin Type II