This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplemental material
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 West, C. M.
Right arrow Articles by Erdos, G. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by West, C. M.
Right arrow Articles by Erdos, G. W.

 Previous Article  |  Next Article 

Eukaryotic Cell, January 2009, p. 27-36, Vol. 8, No. 1
1535-9778/09/$08.00+0     doi:10.1128/EC.00398-07
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

Dependence of Stress Resistance on a Spore Coat Heteropolysaccharide in Dictyostelium{triangledown} ,{dagger}

Christopher M. West,1* Phuong Nguyen,1 Hanke van der Wel,1 Talibah Metcalf,1,{ddagger} Kristin R. Sweeney,2 Ira J. Blader,2 and Gregory W. Erdos3

Department of Biochemistry and Molecular Biology and Oklahoma Center for Medical Glycobiology,1 Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104,2 ICBR, University of Florida, Gainesville, Florida 326113

Received 30 October 2007/ Accepted 1 September 2008

In Dictyostelium, sporulation occurs synchronously as prespore cells approach the apex of the aerial stalk during culmination. Each prespore cell becomes surrounded by its own coat comprised of a core of crystalline cellulose and a branched heteropolysaccharide sandwiched between heterogeneous cysteine-rich glycoproteins. The function of the heteropolysaccharide, which consists of galactose and N-acetylgalactosamine, is unknown. Two glycosyltransferase-like genes encoding multifunctional proteins, each with predicted features of a heteropolysaccharide synthase, were identified in the Dictyostelium discoideum genome. pgtB and pgtC transcripts were modestly upregulated during early development, and pgtB was further intensely upregulated at the time of heteropolysaccharide accumulation. Disruption of either gene reduced synthase-like activity and blocked heteropolysaccharide formation, based on loss of cytological labeling with a lectin and absence of component sugars after acid hydrolysis. Cell mixing experiments showed that heteropolysaccharide expression is spore cell autonomous, suggesting a physical association with other coat molecules during assembly. Mutant coats expressed reduced levels of crystalline cellulose based on chemical analysis after acid degradation, and cellulose was heterogeneously affected based on flow cytometry and electron microscopy. Mutant coats also contained elevated levels of selected coat proteins but not others and were sensitive to shear. Mutant spores were unusually susceptible to hypertonic collapse and damage by detergent or hypertonic stress. Thus, the heteropolysaccharide is essential for spore integrity, which can be explained by a role in the formation of crystalline cellulose and regulation of the protein content of the coat.

* Corresponding author. Mailing address: Department of Biochemistry and Molecular Biology, 975 NE 10th St., BRC 417, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104. Phone: (405) 271-4147. Fax: (405) 271-3910. E-mail: Cwest2{at}ouhsc.edu

{triangledown} Published ahead of print on 7 November 2008.

{dagger} Supplemental material for this article may be found at http://ec.asm.org/.

{ddagger} Present address: Department of Molecular Microbiology and Immunology, Johns Hopkins University School of Public Health, Baltimore, MD 21205.

Eukaryotic Cell, January 2009, p. 27-36, Vol. 8, No. 1
1535-9778/09/$08.00+0     doi:10.1128/EC.00398-07
Copyright © 2009, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Wang, Z. A., van der Wel, H., Vohra, Y., Buskas, T., Boons, G.-J., West, C. M. (2009). Role of a Cytoplasmic Dual-function Glycosyltransferase in O2 Regulation of Development in Dictyostelium. J. Biol. Chem. 284: 28896-28904 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»