title: Crosstalk between Akt/GSK3β signaling and dynamin-1 regulates clathrin-mediated endocytosis.
abstract: Clathrin-mediated endocytosis (CME) regulates signaling from the plasma membrane. Analysis of clathrin-coated pit (CCP) dynamics led us to propose the existence of a rate-limiting, regulatory step(s) that monitor the fidelity of early stages in CCP maturation. Here we show that nascent endocytic vesicles formed in mutant cells displaying rapid, dysregulated CME are defective in early endosomal trafficking, maturation and acidification, confirming the importance of this "checkpoint." Dysregulated CME also alters EGF receptor signaling and leads to constitutive activation of the protein kinase Akt. Dynamin-1, which was thought to be neuron specific, is activated by the Akt/GSK3β signaling cascade in non-neuronal cells to trigger rapid, dysregulated CME. Acute activation of dynamin-1 in RPE cells by inhibition of GSK3β accelerates CME, alters CCP dynamics and, unexpectedly, increases the rate of CCP initiation. CRISPR-Cas9n-mediated knockout and reconstitution studies establish that dynamin-1 is activated by Akt/GSK3β signaling in H1299 non-small lung cancer cells. These findings provide direct evidence for an isoform-specific role for dynamin in regulating CME and reveal a feed-forward pathway that could link signaling from cell surface receptors to the regulation of CME.
authors.affiliation: Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Carlos R
authors.initials: CR
authors.lastname: Reis
authors.affiliation: Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Ping-Hung
authors.initials: PH
authors.lastname: Chen
authors.affiliation: Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Saipraveen
authors.initials: S
authors.lastname: Srinivasan
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
authors.forename: François
authors.initials: F
authors.lastname: Aguet
authors.affiliation: Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Marcel
authors.initials: M
authors.lastname: Mettlen
authors.affiliation: Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA Sandra.Schmid@utsouthwestern.edu.
authors.forename: Sandra L
authors.initials: SL
authors.lastname: Schmid
mesh_terms: D002460:Cell Line; D022163:Clathrin-Coated Vesicles / Q000378:metabolism; D034284:Dynamin I / Q000378:metabolism*; D004705:Endocytosis; D004847:Epithelial Cells / Q000502:physiology*; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D060066:Protein Interaction Maps; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; D051057:Proto-Oncogene Proteins c-akt; D038362:Glycogen Synthase Kinase 3; D034284:Dynamin I
keywords: CCP maturation; CME; dynamin; endosomal trafficking; signaling