QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online 22 December 2004
doi: 10.1242/jcs.01616

This Article Figures Only Full Text Full Text (PDF) All Versions of this Article: jcs.01616v1 118/2/323    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Siriputthaiwan, P. Articles by Dumas, B. Search for Related Content PubMed PubMed Citation Articles by Siriputthaiwan, P. Articles by Dumas, B. Social Bookmarking                         What's this?

Functional analysis of CLPT1, a Rab/GTPase required for protein secretion and pathogenesis in the plant fungal pathogen Colletotrichum lindemuthianum

¹ UMR 5546 CNRS-Université Paul Sabatier
² IFR 40 Pôle de Biotechnologie Végétale, 24 Chemin de Borde Rouge, BP17 Auzeville, 31326 Castanet-Tolosan, France

^* Author for correspondence (e-mail: dumas{at}scsv.ups-tlse.fr)

Accepted 27 October 2004

In eukaryotic cells, Rab/GTPases are major regulators of vesicular trafficking and are involved in essential processes including exocytosis, endocytosis and cellular differentiation. To investigate the role of these proteins in fungal pathogenicity, a dominant-negative mutant allele of CLPT1, a Rab/GTPase of the bean pathogen Colletotrichum lindemuthianum, was expressed in transgenic strains. This mutated gene encodes the amino-acid substitution N123I analogous to the N133I substitution in a known trans-dominant inhibitor of the Sec4 Rab/GTPase from Saccharomyces cerevisiae. A pectinase gene promoter was used to drive the CLPT1(N123I) allele in C. lindemuthianum, allowing the expression of the foreign gene on pectin medium and during pathogenesis, but not on glucose. The same strategy was used to overexpress the wild-type CLPT1 allele. During growth on pectin medium, production of extracellular pectinases was strongly impaired only in CLPT1(N123I)-expressing strains. Cytological analysis revealed that CLPT1(N123I) strains accumulated intracellular aggregates only on pectin, resulting from the fusion of vesicles containing polysaccharides or glycoproteins. Moreover, these strains showed a severe reduction of pathogenesis and were unable to penetrate the host cells. These results indicated that the Rab/GTPase CLPT1 is essential for fungal pathogenesis by regulating the intracellular transport of secretory vesicles involved in the delivery of proteins to the extracellular medium and differentiation of infectious structures.

Key words: Fungal pathogenicity, Colletotrichum lindemuthianum, Secretion

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

This article has been cited by other articles:

				A. Yoneda and T. L. Doering A Eukaryotic Capsular Polysaccharide Is Synthesized Intracellularly and Secreted via Exocytosis Mol. Biol. Cell, December 1, 2006; 17(12): 5131 - 5140. [Abstract] [Full Text] [PDF]