JCB logo
CrossRef
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents

This Article
Right arrow Full Text (PDF, 1075K)
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JCB
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Maul, G. G.
Right arrow Articles by Borun, T. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Maul, G. G.
Right arrow Articles by Borun, T. W.
Social Bookmarking
 Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?
The Journal of Cell Biology, Vol 55, 433-447, Copyright © 1972 by Rockefeller University Press

ARTICLE

TIME SEQUENCE OF NUCLEAR PORE FORMATION IN PHYTOHEMAGGLUTININ-STIMULATED LYMPHOCYTES AND IN HELA CELLS DURING THE CELL CYCLE

Gerd G. Maul 1, Helmut M. Maul 1, Joseph E. Scogna 1, Michael W. Lieberman 1, Gary S. Stein 1, Betty Yee-Li Hsu 1, and Thaddeus W. Borun 1

1 From the Department of Pathology, Fels Research Institute, and the Department of Biochemistry, Temple University School of Medicine, Philadelphia, Pennsylvania 19140

The time sequence of nuclear pore frequency changes was determined for phytohemagglutinin (PHA)-stimulated human lymphocytes and for HeLa S-3 cells during the cell cycle. The number of nuclear pores/nucleus was calculated from the experimentally determined values of nuclear pores/µ2 and the nuclear surface. In the lymphocyte system the number of pores/nucleus approximately doubles during the 48 hr after PHA stimulation. The increase in pore frequency is biphasic and the first increase seems to be related to an increase in the rate of protein synthesis. The second increase in pores/nucleus appears to be correlated with the onset of DNA synthesis. In the HeLa cell system, we could also observe a biphasic change in pore formation. Nuclear pores are formed at the highest rate during the first hour after mitosis. A second increase in the rate of pore formation corresponds in time with an increase in the rate of nuclear acidic protein synthesis shortly before S phase. The total number of nuclear pores in HeLa cells doubles from sim2000 in G1 to sim4000 at the end of the cell cycle. The doubling of the nuclear volume and the number of nuclear pores might be correlated to the doubling of DNA content. Another correspondence with the nuclear pore number in S phase is found in the number of simultaneously replicating replication sites. This number may be fortuitous but leads to the rather speculative possibility that the nuclear pore might be the site of initiation and/or replication of DNA as well as the site of nucleocytoplasmic exchange. That is, the nuclear pore complex may have multiple functions.

Submitted on March 3, 1972
Revised on June 16, 1972


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:



  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents