title: Mechanical force regulates integrin turnover in Drosophila in vivo.
abstract: Regulated assembly and disassembly, or turnover, of integrin-mediated cell-extracellular matrix (ECM) adhesions is essential for dynamic cell movements and long-term tissue maintenance. For example, in Drosophila, misregulation of integrin turnover disrupts muscle-tendon attachment at myotendinous junctions (MTJs). We demonstrate that mechanical force, which modulates integrin activity, also regulates integrin and intracellular adhesion complex (IAC) turnover in vivo. Using conditional mutants to alter the tensile force on MTJs, we found that the proportion of IAC components undergoing turnover inversely correlated with the force applied on MTJs. This effect was disrupted by point mutations in β-integrin that interfere with ECM-induced conformational changes and activation of β-integrin or integrin-mediated cytoplasmic signalling. These mutants also disrupted integrin dynamics at MTJs during larval development. Together, these data suggest that specific β-integrin-mediated signals regulate adhesion turnover in response to tension during tissue formation. We propose that integrin-ECM adhesive stability is continuously controlled by force in vivo through integrin-dependent auto-regulatory feedback mechanisms so that tissues can quickly adapt to and withstand mechanical stresses.
authors.affiliation: Department of Cellular and Physiological Sciences, University of British Columbia, Life Science Institute, Vancouver, British Columbia V6T 1Z3, Canada.
authors.forename: Mary
authors.initials: M
authors.lastname: Pines
authors.forename: Raibatak
authors.initials: R
authors.lastname: Das
authors.forename: Stephanie J
authors.initials: SJ
authors.lastname: Ellis
authors.forename: Alexander
authors.initials: A
authors.lastname: Morin
authors.forename: Stefan
authors.initials: S
authors.lastname: Czerniecki
authors.forename: Lin
authors.initials: L
authors.lastname: Yuan
authors.forename: Markus
authors.initials: M
authors.lastname: Klose
authors.forename: Daniel
authors.initials: D
authors.lastname: Coombs
authors.forename: Guy
authors.initials: G
authors.lastname: Tanentzapf
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000235:genetics / Q000502:physiology; D002465:Cell Movement / Q000235:genetics / Q000502:physiology; D021982:Cell-Matrix Junctions / Q000378:metabolism / Q000502:physiology*; D003593:Cytoplasm / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D004330:Drosophila / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D005109:Extracellular Matrix / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D039641:Integrin beta Chains / Q000378:metabolism*; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism / Q000502:physiology; D017354:Point Mutation; D013314:Stress, Mechanical; D013710:Tendons / Q000378:metabolism / Q000502:physiology
chemical_list: D039641:Integrin beta Chains