title: ER network homeostasis is critical for plant endosome streaming and endocytosis.
abstract: Eukaryotic cells internalize cargo at the plasma membrane via endocytosis, a vital process that is accomplished through a complex network of endosomal organelles. In mammalian cells, the ER is in close association with endosomes and regulates their fission. Nonetheless, the physiological role of such interaction on endocytosis is yet unexplored. Here, we probed the existence of ER-endosome association in plant cells and assayed its physiological role in endocytosis. Through live-cell imaging and electron microscopy studies, we established that endosomes are extensively associated with the plant ER, supporting conservation of interaction between heterotypic organelles in evolutionarily distant kingdoms. Furthermore, by analyzing ER-endosome dynamics in genetic backgrounds with defects in ER structure and movement, we also established that the ER network integrity is necessary for homeostasis of the distribution and streaming of various endosome populations as well as for efficient endocytosis. These results support a novel model that endocytosis homeostasis depends on a spatiotemporal control of the endosome dynamics dictated by the ER membrane network.
authors.affiliation: MSU-DOE Plant Research Lab and Plant Biology Department, Michigan State University , East Lansing, MI , USA.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Stefano
authors.affiliation: MSU-DOE Plant Research Lab and Plant Biology Department, Michigan State University , East Lansing, MI , USA.
authors.forename: Luciana
authors.initials: L
authors.lastname: Renna
authors.affiliation: MSU-DOE Plant Research Lab and Plant Biology Department, Michigan State University , East Lansing, MI , USA.
authors.forename: YaShiuan
authors.initials: Y
authors.lastname: Lai
authors.affiliation: MSU-DOE Plant Research Lab and Plant Biology Department, Michigan State University , East Lansing, MI , USA.
authors.forename: Erin
authors.initials: E
authors.lastname: Slabaugh
authors.affiliation: MSU-DOE Plant Research Lab and Plant Biology Department, Michigan State University , East Lansing, MI , USA.
authors.forename: Nicole
authors.initials: N
authors.lastname: Mannino
authors.affiliation: Department of Botany, University of Wisconsin-Madison, Madison, WI, USA; R.M. Bock Laboratories Cell and Molecular Biology, University of Wisconsin-Madison, Madison, WI, USA.
authors.forename: Rafael A
authors.identifier: 0000-0002-6675-3836
authors.initials: RA
authors.lastname: Buono
authors.affiliation: Department of Botany, University of Wisconsin-Madison, Madison, WI, USA; R.M. Bock Laboratories Cell and Molecular Biology, University of Wisconsin-Madison, Madison, WI, USA; Department of Genetics, University of Wisconsin-Madison, Madison, WI, USA.
authors.forename: Marisa S
authors.initials: MS
authors.lastname: Otegui
authors.affiliation: MSU-DOE Plant Research Lab and Plant Biology Department, Michigan State University , East Lansing, MI , USA.
authors.forename: Federica
authors.initials: F
authors.lastname: Brandizzi
keywords: Arabidopsis; endocytosis; endoplasmic reticulum; organelle streaming