A eukaryotic capsular polysaccharide is synthesized intracellularly and secreted via exocytosis.

ABSTRACT: Cryptococcus neoformans, which causes fatal infection in immunocompromised individuals, has an elaborate polysaccharide capsule surrounding its cell wall. The cryptococcal capsule is the major virulence factor of this fungal organism, but its biosynthetic pathways are virtually unknown. Extracellular polysaccharides of eukaryotes may be made at the cell membrane or within the secretory pathway. To test these possibilities for cryptococcal capsule synthesis, we generated a secretion mutant in C. neoformans by mutating a Sec4/Rab8 GTPase homolog. At a restrictive temperature, the mutant displayed reduced growth and protein secretion, and accumulated approximately 100-nm vesicles in a polarized manner. These vesicles were not endocytic, as shown by their continued accumulation in the absence

SUBMITTER: Yoneda A 

PROVIDER: S-EPMC1679678 | biostudies-literature | 2006 Dec

REPOSITORIES: biostudies-literature