Variations in signal-mediated nuclear transport during the cell cycle in BALB/c 3T3 cells.
Signal-mediated nuclear import was investigated in proliferating BALB/c 3T3 cells 1, 2, 4, 6, 8, 12, 18, and 21 h after the onset of anaphase. Using nucleoplasmin-coated colloidal gold particles to assay transport capacity, it was found that import was greatest at 1 h postanaphase (after complete reformation of the nuclear envelope). At this time, both the relative rate of gold uptake and the functional size of the transport channels were significantly greater than in control cells, which were randomly selected from nonsynchronized cultures. At 21 h, there was a decrease in the size of the transport channel, but not the rate of nuclear import. This suggests that these two factors are regulated independently. No changes in transport capacity, compared to controls, were detected at other times in the cell cycle.
Department of Anatomy and Cell Biology, University of Florida, College of Medicine, Gainesville 32610.
C M
CM
Feldherr
D
D
Akin
D016475:3T3 Cells; D000705:Anaphase; D000818:Animals; D002453:Cell Cycle / Q000502:physiology*; D002455:Cell Division; D002467:Cell Nucleus / Q000378:metabolism*; D003102:Colloids; D004247:DNA / Q000096:biosynthesis; D005260:Female; D006046:Gold / Q000493:pharmacokinetics; D007700:Kinetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008845:Microinjections; D009687:Nuclear Proteins / Q000378:metabolism; D056489:Nucleoplasmins; D009865:Oocytes / Q000378:metabolism; D010750:Phosphoproteins; D016196:S Phase; D015398:Signal Transduction; D013997:Time Factors; D014981:Xenopus
D003102:Colloids; D009687:Nuclear Proteins; D056489:Nucleoplasmins; D010750:Phosphoproteins; D006046:Gold; D004247:DNA