title: Role of endosomes in simian virus 40 entry and infection.
abstract: After binding to its cell surface receptor ganglioside GM1, simian virus 40 (SV40) is endocytosed by lipid raft-mediated endocytosis and slowly transported to the endoplasmic reticulum, where partial uncoating occurs. We analyzed the intracellular pathway taken by the virus in HeLa and CV-1 cells by using a targeted small interfering RNA (siRNA) silencing screen, electron microscopy, and live-cell imaging as well as by testing a variety of cellular inhibitors and other perturbants. We found that the virus entered early endosomes, late endosomes, and probably endolysosomes before reaching the endoplasmic reticulum and that this pathway was part of the infectious route. The virus was especially sensitive to a variety of perturbations that inhibited endosome acidification and maturation. Contrary to our previous models, which postulated the passage of the virus through caveolin-rich organelles that we called caveosomes, we conclude that SV40 depends on the classical endocytic pathway for infectious entry.
authors.affiliation: ETH Zurich, Institute of Biochemistry, Schafmattstrasse 18, 8093 Zurich, Switzerland.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Engel
authors.forename: Thomas
authors.initials: T
authors.lastname: Heger
authors.forename: Roberta
authors.initials: R
authors.lastname: Mancini
authors.forename: Fabian
authors.initials: F
authors.lastname: Herzog
authors.forename: Jürgen
authors.initials: J
authors.lastname: Kartenbeck
authors.forename: Arnold
authors.initials: A
authors.lastname: Hayer
authors.forename: Ari
authors.initials: A
authors.lastname: Helenius
mesh_terms: D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D004705:Endocytosis; D011992:Endosomes / Q000378:metabolism*; D020868:Gene Silencing; D006801:Humans; D008853:Microscopy / Q000379:methods; D013539:Simian virus 40 / Q000502:physiology*; D053586:Virus Internalization