Microtubule-dependent plus- and minus end-directed motilities are competing processes for nuclear targeting of adenovirus.
Adenovirus (Ad) enters target cells by receptor-mediated endocytosis, escapes to the cytosol, and then delivers its DNA genome into the nucleus. Here we analyzed the trafficking of fluorophore-tagged viruses in HeLa and TC7 cells by time-lapse microscopy. Our results show that native or taxol-stabilized microtubules (MTs) support alternating minus- and plus end-directed movements of cytosolic virus with elementary speeds up to 2.6 micrometer/s. No directed movement was observed in nocodazole-treated cells. Switching between plus- and minus end-directed elementary speeds at frequencies up to 1 Hz was observed in the periphery and near the MT organizing center (MTOC) after recovery from nocodazole treatment. MT-dependent motilities allowed virus accumulation near the MTOC at population speeds of 1-10 micrometer/min, depending on the cell type. Overexpression of p50/dynamitin, which is known to affect dynein-dependent minus end-directed vesicular transport, significantly reduced the extent and the frequency of minus end-directed migration of cytosolic virus, and increased the frequency, but not the extent of plus end-directed motility. The data imply that a single cytosolic Ad particle engages with two types of MT-dependent motor activities, the minus end- directed cytoplasmic dynein and an unknown plus end- directed activity.
Institute of Zoology, University of Zürich, CH-8057 Zürich, Switzerland.
M
M
Suomalainen
M Y
MY
Nakano
S
S
Keller
K
K
Boucke
R P
RP
Stidwill
U F
UF
Greber
D000260:Adenoviruses, Human / Q000472:pathogenicity / Q000502:physiology*; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002467:Cell Nucleus / Q000821:virology*; D002522:Chlorocebus aethiops; D003600:Cytosol / Q000821:virology; D017931:DNA Primers / Q000235:genetics; D000072159:Dynactin Complex; D004398:Dyneins / Q000502:physiology; D005456:Fluorescent Dyes; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D008164:Luminescent Proteins / Q000235:genetics; D008856:Microscopy, Fluorescence; D008869:Microtubule-Associated Proteins / Q000502:physiology; D008870:Microtubules / Q000187:drug effects / Q000502:physiology* / Q000821:virology; D020409:Molecular Motor Proteins / Q000502:physiology; D009068:Movement; D015739:Nocodazole / Q000494:pharmacology; D017239:Paclitaxel / Q000494:pharmacology; D014779:Virus Replication
C000606361:DCTN2 protein, human; D017931:DNA Primers; D000072159:Dynactin Complex; D005456:Fluorescent Dyes; D008164:Luminescent Proteins; D008869:Microtubule-Associated Proteins; D020409:Molecular Motor Proteins; D049452:Green Fluorescent Proteins; D004398:Dyneins; D017239:Paclitaxel; D015739:Nocodazole