title: Vaccinia virus dissemination requires p21-activated kinase 1.
abstract: The orthopoxvirus vaccinia virus (VACV) interacts with both actin and microtubule cytoskeletons in order to generate and spread progeny virions. Here, we present evidence demonstrating the involvement of PAK1 (p21-activated kinase 1) in the dissemination of VACV. Although PAK1 activation has previously been associated with optimal VACV entry via macropinocytosis, its absence does not affect the production of intracellular mature virions (IMVs) and extracellular enveloped virions (EEVs). Our data demonstrate that low-multiplicity infection of PAK1(-/-) MEFs leads to a reduction in plaque size followed by decreased production of both IMVs and EEVs, strongly suggesting that virus spread was impaired in the absence of PAK1. Confocal and scanning electron microscopy showed a substantial reduction in the amount of VACV-induced actin tails in PAK1(-/-) MEFs, but no significant alteration in the total amount of cell-associated enveloped virions (CEVs). Furthermore, the decreased VACV dissemination in PAK1(-/-) cells was correlated with the absence of phosphorylated ARPC1 (Thr21), a downstream target of PAK1 and a key regulatory subunit of the ARP2/3 complex, which is necessary for the formation of actin tails and viral spread. We conclude that PAK1, besides its role in virus entry, also plays a relevant role in VACV dissemination.
authors.affiliation: Signal Transduction Group, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, Minas Gerais, 31270-901, Brazil.|Viruses Laboratory, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil.
authors.forename: Luciana G
authors.initials: LG
authors.lastname: Andrade
authors.affiliation: Signal Transduction Group, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, Minas Gerais, 31270-901, Brazil.|Viruses Laboratory, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil.|Department of Pathology, University of Cambridge, Cambridge, CB2 1QP, UK.
authors.forename: Jonas D
authors.initials: JD
authors.lastname: Albarnaz
authors.affiliation: Signal Transduction Group, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, Minas Gerais, 31270-901, Brazil.|Viruses Laboratory, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil.
authors.forename: Fernanda L B
authors.initials: FL
authors.lastname: Mügge
authors.affiliation: Immunobiophotonics Laboratory, Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil.
authors.forename: Bruna A
authors.initials: BA
authors.lastname: David
authors.affiliation: Viruses Laboratory, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil.
authors.forename: Jônatas S
authors.initials: JS
authors.lastname: Abrahão
authors.affiliation: Laboratory of Basic and Applied Virology, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil.
authors.forename: Flávio G
authors.initials: FG
authors.lastname: da Fonseca
authors.affiliation: Viruses Laboratory, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil.
authors.forename: Erna G
authors.initials: EG
authors.lastname: Kroon
authors.affiliation: Immunobiophotonics Laboratory, Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil.
authors.forename: Gustavo B
authors.initials: GB
authors.lastname: Menezes
authors.affiliation: Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, USA.
authors.forename: Grant
authors.initials: G
authors.lastname: McFadden
authors.affiliation: Signal Transduction Group, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, Minas Gerais, 31270-901, Brazil. claudio.bonjardim@pq.cnpq.br.|Viruses Laboratory, Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil. claudio.bonjardim@pq.cnpq.br.
authors.forename: Cláudio A
authors.initials: CA
authors.lastname: Bonjardim
mesh_terms: D000818:Animals; D001692:Biological Transport; D002478:Cells, Cultured; D004705:Endocytosis; D054884:Host-Pathogen Interactions; D051379:Mice; D018345:Mice, Knockout; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D014616:Vaccinia virus / Q000502:physiology*; D053586:Virus Internalization; D054462:p21-Activated Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: C515905:Pak1 protein, mouse; D054462:p21-Activated Kinases