Myosin-X facilitates Shigella-induced membrane protrusions and cell-to-cell spread.
The intracellular pathogen Shigella flexneri forms membrane protrusions to spread from cell to cell. As protrusions form, myosin-X (Myo10) localizes to Shigella. Electron micrographs of immunogold-labelled Shigella-infected HeLa cells reveal that Myo10 concentrates at the bases and along the sides of bacteria within membrane protrusions. Time-lapse video microscopy shows that a full-length Myo10 GFP-construct cycles along the sides of Shigella within the membrane protrusions as these structures progressively lengthen. RNAi knock-down of Myo10 is associated with shorter protrusions with thicker stalks, and causes a >80% decrease in confluent cell plaque formation. Myo10 also concentrates in membrane protrusions formed by another intracellular bacteria, Listeria, and knock-down of Myo10 also impairs Listeria plaque formation. In Cos7 cells (contain low concentrations of Myo10), the expression of full-length Myo10 nearly doubles Shigella-induced protrusion length, and lengthening requires the head domain, as well as the tail-PH domain, but not the FERM domain. The GFP-Myo10-HMM domain localizes to the sides of Shigella within membrane protrusions and the GFP-Myo10-PH domain localizes to host cell membranes. We conclude thatMyo10 generates the force to enhance bacterial-induced protrusions by binding its head region to actin filaments and its PH tail domain to the peripheral membrane.
Department of Medicine, Division of Infectious Diseases, University of Florida College of Medicine, Gainesville, FL, USA.
Ellen A
EA
Bishai
Department of Medicine, Division of Infectious Diseases, University of Florida College of Medicine, Gainesville, FL, USA.
Gurjit S
GS
Sidhu
Department of Medicine, Division of Infectious Diseases, University of Florida College of Medicine, Gainesville, FL, USA.
Wei
W
Li
Department of Medicine, Division of Infectious Diseases, University of Florida College of Medicine, Gainesville, FL, USA.
Jess
J
Dhillon
Department of Cell and Molecular Physiology, University of North Carolina, Chapel Hill, NC, USA.
Aparna B
AB
Bohil
Department of Cell and Molecular Physiology, University of North Carolina, Chapel Hill, NC, USA.
Richard E
RE
Cheney
Department of Medicine, Division of Translational Medicine, Brigham and Women's Hospital, Harvard University, Boston, MA, USA.
John H
JH
Hartwig
Department of Medicine, Division of Infectious Diseases, University of Florida College of Medicine, Gainesville, FL, USA.
Frederick S
FS
Southwick
D000818:Animals; D019556:COS Cells; D002462:Cell Membrane / Q000378:metabolism / Q000382:microbiology; D002522:Chlorocebus aethiops; D006367:HeLa Cells; D054884:Host-Pathogen Interactions; D006801:Humans; D008087:Listeria / Q000472:pathogenicity; D016253:Microscopy, Immunoelectron; D018715:Microscopy, Video; D009218:Myosins / Q000378:metabolism*; D012763:Shigella flexneri / Q000502:physiology*
C498718:MYO10 protein, human; D009218:Myosins