Conidial Surface associated proteins of Aspergillus flavus and Aspergillus fumigatus
Ontology highlight
ABSTRACT:
INSTRUMENT(S): LTQ Orbitrap Velos
ORGANISM(S): Aspergillus Fumigatus Af293 Aspergillus Flavus (strain Atcc 200026 / Fgsc A1120 / Nrrl 3357 / Jcm 12722 / Srrc 167)
SUBMITTER: 
Jeya Maheshwari Jayapal
LAB HEAD: Jeya Maheshwari
PROVIDER: PXD022824 | Pride | 2025-01-17
REPOSITORIES: pride
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| 1698_CSP.sf3 | Other | |||
| DAL_CSP.sf3 | Other | |||
| UP_Aflavus_180910.fasta | Fasta | |||
| UP_Afumigatus_AF293_240118.fasta | Fasta | |||
| VL_CI1698_MQ_A_1.mzid.gz | Mzid |
Items per page: 5 1 - 5 of 101 |
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Project description:Immune inertness of Aspergillus fumigatus conidia, an airborne fungal pathogen, is attributed to its surface rodlet-layer made up of RodAp, a protein belonging to the hydrophobin family, characterized by eight conserved cysteine residues forming four disulfide bonding. Earlier, we showed that the conserved cysteine residue point (ccrp) mutations result in conidia devoid of the rodlet-layer. Here we extended our study in comparing ccrp-mutation with RODA deletion on their mutant conidial surface organization, permeability and immunoreactivity. Western blot using anti-RodAp antibodies indicated the absence of RodAp in the cytoplasm of ccrp-mutant conidia. Upon immunolabelling, ccrp-mutant conidia showed strong positivity for -(1,3)-glucan and weak positivity for -(1,3)-glucan, which was reverse in ∆rodA conidia, and the parental strain conidia were negative; all of their conidial cell wall permeability was similar. Proteomic analyses of the conidial surface exposed proteins of the ccrp-mutants, although lower in number, showed more similarities with the parental strain, but a significant difference with the RODA deletion mutant strain. Further, ccrp-mutant conidia are less immunostimulatory compared to ∆rodA conidia. Together, our data suggest that (i) the conserved cysteine residues are essential for the trafficking of RodAp and the organization of rodlet-layer on the conidial surface, and (ii) point-mutation could be an alternative strategy to study the proteins involved in the organization of fungal cell wall.
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Project description:We identified the proteins secreted by A. flavus and A. fumigatus conidia during the early stages of growth. A comparative analysis was done between the exoproteome of the two species to identify the core proteins that were common between the two Aspergilli as well as species specific signature protiens. The common proteins included cell wall polysaccharide modifying enzymes and those required for nutrient acquisition. The core proteome is an indication that A. flavus and A. fumigatus share the common events during germination and growth. On the other hand, each Aspergillus had a unique subset of proteins that could be potential virulence factors or effector molecules. This species-specific exoprotein signature probably reflects the specific requirements of the Aspergillus pathogen to establish an infection in a particular niche.
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Project description:The surface of Aspergillus fumigatus conidia, the first structure recognized by the host immune system, is covered by rodlets. We report that this outer cell wall layer contains two hydrophobins, RodAp and RodBp, which are found as highly insoluble complexes. The RODA gene was previously characterized, and DeltarodA conidia do not display a rodlet layer (N. Thau, M. Monod, B. Crestani, C. Rolland, G. Tronchin, J. P. Latgé, and S. Paris, Infect. Immun. 62:4380-4388, 1994). The RODB gene was cloned and disrupted. RodBp was highly homologous to RodAp and different from DewAp of A. nidulans. DeltarodB conidia had a rodlet layer similar to that of the wild-type conidia. Therefore, unlike RodAp, RodBp is not required for rodlet formation. The surface of DeltarodA conidia is granular; in contrast, an amorphous layer is present at the surface of the conidia of the DeltarodA DeltarodB double mutant. These data show that RodBp plays a role in the structure of the conidial cell wall. Moreover, rodletless mutants are more sensitive to killing by alveolar macrophages, suggesting that RodAp or the rodlet structure is involved in the resistance to host cells.
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Project description:Maize kernels are susceptible to infection by the opportunistic pathogen Aspergillus flavus. Infection results in reduction of grain quality and contamination of kernels with the highly carcinogenic mycotoxin, aflatoxin. To understand host response to infection by the fungus, transcription of approximately 9,000 maize genes were monitored during the host-pathogen interaction with a custom-designed Affymetrix GeneChip® DNA array. More than 1,000 maize genes were found differentially expressed at a fold change of 2 or greater. This included the up regulation of defense-related genes and signaling pathways. Transcriptional changes also were observed in primary metabolism genes. Starch biosynthetic genes were down regulated during infection, while genes encoding maize hydrolytic enzymes, presumably involved in the degradation of host reserves, were up regulated. These data indicate that infection of the maize kernel A. flavus induced metabolic changes in the kernel, including the production of a defense response, as well as a disruption in kernel development. Maize kernels were mock inoculated at the blister (R2) or dough (R4) stage or inoculated with A. flavus at the blister (R2), milk (R3), dough (R4), or dent (R5) stage, and harvested 4 days later. Each treatment consisted of three biological replications. For each biological replication, 8 kernels were ground and RNA was isolated and further processed.
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