title: Positive feedback between Golgi membranes, microtubules and ER exit sites directs de novo biogenesis of the Golgi.
abstract: The Golgi complex is the central organelle of the secretory pathway. It undergoes dynamic changes during the cell cycle, but how it acquires and maintains its complex structure is unclear. To address this question, we have used laser nanosurgery to deplete BSC1 cells of the Golgi complex and have monitored its biogenesis by quantitative time-lapse microscopy and correlative electron microscopy. After Golgi depletion, endoplasmic reticulum (ER) export is inhibited and the number of ER exit sites (ERES) is reduced and does not increase for several hours. Occasional fusion of small post-ER carriers to form the first larger structures triggers a rapid and drastic growth of Golgi precursors, due to the capacity of these structures to attract more carriers by microtubule nucleation and to stimulate ERES biogenesis. Increasing the chances of post-ER carrier fusion close to ERES by depolymerizing microtubules results in the acceleration of Golgi and ERES biogenesis. Taken together, on the basis of our results, we propose a self-organizing principle of the early secretory pathway that integrates Golgi biogenesis, ERES biogenesis and the organization of the microtubule network by positive-feedback loops.
authors.affiliation: European Molecular Biology Laboratory (EMBL), Cell biology and biophysics unit.
authors.forename: Paolo
authors.initials: P
authors.lastname: Ronchi
authors.affiliation: European Molecular Biology Laboratory (EMBL), Advanced Light Microscopy.
authors.forename: Christian
authors.initials: C
authors.lastname: Tischer
authors.affiliation: European Molecular Biology Laboratory (EMBL), Electron Microscopy Core Facilities, Meyerhofstrasse 1, 69117 Heidelberg, Germany.
authors.forename: Devrim
authors.initials: D
authors.lastname: Acehan
authors.affiliation: European Molecular Biology Laboratory (EMBL), Cell biology and biophysics unit European Molecular Biology Laboratory (EMBL), Advanced Light Microscopy pepperko@embl.de.
authors.forename: Rainer
authors.initials: R
authors.lastname: Pepperkok
mesh_terms: D000818:Animals; D001692:Biological Transport; D002460:Cell Line; D002522:Chlorocebus aethiops; D004721:Endoplasmic Reticulum / Q000378:metabolism* / Q000648:ultrastructure; D006056:Golgi Apparatus / Q000378:metabolism* / Q000648:ultrastructure; D008854:Microscopy, Electron; D008870:Microtubules / Q000378:metabolism* / Q000648:ultrastructure; D059008:Time-Lapse Imaging
keywords: ER exit site biogenesis; Early secretory pathway organization; Golgi biogenesis; Laser nanosurgery