Entry of the two infectious forms of vaccinia virus at the plasma membane is signaling-dependent for the IMV but not the EEV.
The simpler of the two infectious forms of vaccinia virus, the intracellular mature virus (IMV) is known to infect cells less efficiently than the extracellular enveloped virus (EEV), which is surrounded by an additional, TGN-derived membrane. We show here that when the IMV binds HeLa cells, it activates a signaling cascade that is regulated by the GTPase rac1 and rhoA, ezrin, and both tyrosine and protein kinase C phosphorylation. These cascades are linked to the formation of actin and ezrin containing protrusions at the plasma membrane that seem to be essential for the entry of IMV cores. The identical cores of the EEV also appear to enter at the cell surface, but surprisingly, without the need for signaling and actin/membrane rearrangements. Thus, in addition to its known role in wrapping the IMV and the formation of intracellular actin comets, the membrane of the EEV seems to have evolved the capacity to enter cells silently, without a need for signaling.
Locker
J K
JK
European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany. Krijnse@EMBL-Heidelberg.DE
Kuehn
A
A
Schleich
S
S
Rutter
G
G
Hohenberg
H
H
Wepf
R
R
Griffiths
G
G
D000199:Actins / Q000378:metabolism; D002462:Cell Membrane / Q000821:virology*; D003598:Cytoskeletal Proteins; D006367:HeLa Cells; D006801:Humans; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D015398:Signal Transduction; D014616:Vaccinia virus / Q000378:metabolism / Q000472:pathogenicity / Q000502:physiology*; D014771:Virion / Q000378:metabolism; D019065:Virus Assembly; D020741:rho GTP-Binding Proteins / Q000378:metabolism; D000099149:Ezrin
D000199:Actins; D003598:Cytoskeletal Proteins; D010750:Phosphoproteins; D011493:Protein Kinase C; D020741:rho GTP-Binding Proteins; D000099149:Ezrin