Effect of herpes simplex virus type 1 infection on nucleoside transport in HeLa S3 cells.
The initial velocity of thymidine uptake was measured in HeLa S3 cells infected with herpes simplex virus type 1 (HSV-1). The rate of nucleoside influx into the cells was shown to increase from as early as 1 h post-infection (p.i.) up to 8 h p.i. This increased uptake was shown to be attributable to a progressively increasing contribution from passive diffusion superimposed upon normal transport. Thus, the specific nucleoside transport system was still operating with unaltered kinetic parameters 8 h after infection. Despite the inhibition of host cell protein synthesis and its replacement by the synthesis of virus-specified proteins, the numbers and affinity of the nucleoside transporters in cells 8 h after infection were virtually unchanged. The increased transport of thymidine in infected cultures was resistant to the nucleoside transport inhibitor dipyridamole, and was correlated with entry of a normally impermeant solute (sucrose) into infected cells. These data suggest that the system for the carrier-mediated facilitated diffusion of nucleosides remains intact in HSV-infected cells, but that progressively increasing passive diffusion takes place. Passive diffusion is the major process operating late after virus infection.
Palú
G
G
Institute of Microbiology, University of Padova Medical School, Italy.
Handschumacher
R E
RE
Parolin
C
C
Stefanelli
S
S
Palatini
P
P
D000345:Affinity Labels / Q000378:metabolism; D001692:Biological Transport / Q000187:drug effects; D002472:Cell Transformation, Viral; D004176:Dipyridamole / Q000494:pharmacology; D006367:HeLa Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008715:Methionine / Q000378:metabolism; D018139:Simplexvirus / Q000235:genetics*; D013395:Sucrose / Q000378:metabolism; D013868:Thioinosine / Q000031:analogs & derivatives / Q000378:metabolism; D013936:Thymidine / Q000378:metabolism*
D000345:Affinity Labels; D013868:Thioinosine; D013395:Sucrose; D004176:Dipyridamole; D008715:Methionine; C001789:4-nitrobenzylthioinosine; D013936:Thymidine