Identification of a putative alpha-glucan synthase essential for cell wall construction and morphogenesis in fission yeast
- Frans Hochstenbach*,†,‡,
- Frans M. Klis†,
- Herman van den Ende†,
- Elly van Donselaar§,
- Peter J. Peters§, and
- Richard D. Klausner*
- *Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892; †Institute for Molecular Cell Biology, BioCentrum Amsterdam, University of Amsterdam, Kruislaan 318, 1098 SM Amsterdam, The Netherlands; and §Department of Cell Biology, Faculty of Medicine and Institute of Biomembranes, Utrecht University, 3584 CX Utrecht, The Netherlands
-
Edited by Phillips W. Robbins, Massachusetts Institute of Technology, Cambridge, MA, and approved June 1, 1998 (received for review February 23, 1998)
Abstract
The cell wall protects fungi against lysis and determines their cell shape. Alpha-glucan is a major carbohydrate component of the fungal cell wall, but its function is unknown and its synthase has remained elusive. Here, we describe a fission yeast gene, ags1 +, which encodes a putative alpha-glucan synthase. In contrast to the structure of other carbohydrate polymer synthases, the predicted Ags1 protein consists of two probable catalytic domains for alpha-glucan assembly, namely an intracellular domain for alpha-glucan synthesis and an extracellular domain speculated to cross-link or remodel alpha-glucan. In addition, the predicted Ags1 protein contains a multipass transmembrane domain that might contribute to transport of alpha-glucan across the membrane. Loss of Ags1p function in a temperature-sensitive mutant results in cell lysis, whereas mutant cells grown at the semipermissive temperature contain decreased levels of cell wall alpha-glucan and fail to maintain rod shapes, causing rounding of the cells. These findings demonstrate that alpha-glucan is essential for fission yeast morphogenesis.
Footnotes
-
↵ ‡ To whom reprint requests should be addressed. e-mail: hochstenbach{at}bio.uva.nl.
-
This paper was submitted directly (Track II) to the Proceedings Office.
-
Data deposition: The sequences reported in this paper have been deposited in the GenBank database (accession nos. AF061180 and AF063305).
- ABBREVIATIONS:
- ags1,
- alpha-glucan synthase I;
- ts,
- temperature sensitive;
- YEA,
- yeast extract/glucose/adenine sulfate;
- YEAS,
- YEA plus sorbitol
- Copyright © 1998, The National Academy of Sciences
