Biomaterial Database

Cell wall alpha-1,3-glucan is required to anchor the Cryptococcus neoformans capsule. 2003

Amy J Reese, and Tamara L Doering

Department of Molecular Microbiology, Washington University School of Medicine, Campus Box 8230, 660 South Euclid Avenue, St Louis, MO 63110-1093, USA.

Cryptococcus neoformans is an opportunistic pathogen responsible for serious disease in humans. Critical for virulence of this fungus is an elaborate polysaccharide capsule, which impedes the host immune response. We found that association of the capsule with the cell requires a specific component of the cell wall, alpha-1,3-glucan. Post-transcriptional inhibition of alpha-1,3-glucan synthase expression, using double-stranded RNA interference, yields cells that are unable to assemble a capsule although they generate its polysaccharide components. The resulting cryptococci are slow-growing and acapsular. This finding demonstrates a novel mode of polysaccharide attachment and an important application of RNA interference in fungi. The elimination of the capsule by reducing the expression of a single gene suggests a potential avenue for antifungal chemotherapy.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D002473	Cell Wall	The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.	Cell Walls,Wall, Cell,Walls, Cell
D003455	Cryptococcus neoformans	A species of the fungus CRYPTOCOCCUS. Its teleomorph is Filobasidiella neoformans.	Blastomyces neoformans,Debaryomyces neoformans,Filobasidiella neoformans,Lipomyces neoformans,Saccharomyces neoformans,Torula neoformans,Torulopsis neoformans,Cryptococcus neoformans var. grubii
D005936	Glucans	Polysaccharides composed of repeating glucose units. They can consist of branched or unbranched chains in any linkages.	Glucan,Polyglucose,Polyglucoses,Glucan (BO),Glucose Polymer,Polycose,Polymer, Glucose
D005964	Glucosyltransferases	Enzymes that catalyze the transfer of glucose from a nucleoside diphosphate glucose to an acceptor molecule which is frequently another carbohydrate. EC 2.4.1.-.	Glucosyltransferase
D006026	Glycoside Hydrolases	Any member of the class of enzymes that catalyze the cleavage of the glycosidic linkage of glycosides and the addition of water to the resulting molecules.	Endoglycosidase,Exoglycosidase,Glycohydrolase,Glycosidase,Glycosidases,Glycoside Hydrolase,Endoglycosidases,Exoglycosidases,Glycohydrolases,Hydrolase, Glycoside,Hydrolases, Glycoside
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D016415	Sequence Alignment	The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.	Sequence Homology Determination,Determination, Sequence Homology,Alignment, Sequence,Alignments, Sequence,Determinations, Sequence Homology,Sequence Alignments,Sequence Homology Determinations
D034622	RNA Interference	A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.	Gene Silencing, Post-Transcriptional,Post-Transcriptional Gene Silencing,Co-Suppression,Cosuppression,Posttranscriptional Gene Silencing,RNA Silencing,RNAi,Co Suppression,Gene Silencing, Post Transcriptional,Gene Silencing, Posttranscriptional,Gene Silencings, Posttranscriptional,Interference, RNA,Post Transcriptional Gene Silencing,Post-Transcriptional Gene Silencings,Silencing, Post-Transcriptional Gene