MCB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Cheng, J.
Right arrow Articles by Ye, X. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Cheng, J.
Right arrow Articles by Ye, X. S.

 Previous Article  |  Next Article 

Molecular and Cellular Biology, September 2001, p. 6198-6209, Vol. 21, No. 18
0270-7306/01/$04.00+0   DOI: 10.1128/MCB.21.18.6198-6209.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.

Cell Cycle Progression and Cell Polarity Require Sphingolipid Biosynthesis in Aspergillus nidulans

Jijun Cheng, Tae-Sik Park, Anthony S. Fischl, and Xiang S. Ye*

Infectious Diseases Research, Lilly Research Laboratories, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, Indiana 46285

Received 1 May 2001/Returned for modification 4 June 2001/Accepted 25 June 2001

Sphingolipids are major components of the plasma membrane of eukaryotic cells and were once thought of merely as structural components of the membrane. We have investigated effects of inhibiting sphingolipid biosynthesis, both in germinating spores and growing hyphae of Aspergillus nidulans. In germinating spores, genetic or pharmacological inactivation of inositol phosphorylceramide (IPC) synthase arrests the cell cycle in G1 and also prevents polarized growth during spore germination. However, inactivation of IPC synthase not only eliminates sphingolipid biosynthesis but also leads to a marked accumulation of ceramide, its upstream intermediate. We therefore inactivated serine palmitoyltransferase, the first enzyme in the sphingolipid biosynthesis pathway, to determine effects of inhibiting sphingolipid biosynthesis without an accumulation of ceramide. This inactivation also prevented polarized growth but did not affect nuclear division of germinating spores. To see if sphingolipid biosynthesis is required to maintain polarized growth, and not just to establish polarity, we inhibited sphingolipid biosynthesis in cells in which polarity was already established. This inhibition rapidly abolished normal cell polarity and promoted cell tip branching, which normally never occurs. Cell tip branching was closely associated with dramatic changes in the normally highly polarized actin cytoskeleton and found to be dependent on actin function. The results indicate that sphingolipids are essential for the establishment and maintenance of cell polarity via control of the actin cytoskeleton and that accumulation of ceramide is likely responsible for arresting the cell cycle in G1.

* Corresponding author. Mailing address: Infectious Diseases Research, Lilly Research Laboratories, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN 46285. Phone: (317) 277-1467. Fax: (317) 277-0778. E-mail: Ye_Xiang{at}lilly.com.

Molecular and Cellular Biology, September 2001, p. 6198-6209, Vol. 21, No. 18
0270-7306/01/$04.00+0   DOI: 10.1128/MCB.21.18.6198-6209.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 2001 by the American Society for Microbiology. All rights reserved.