eas (also ccg-2, clock-controlled gene 2) encodes a class I hydrophobin that forms the rodlet layer on the surface of Neurospora crassa macroconidia and aerial hyphae. This small, amphipathic, self-assembling protein confers spore-surface hydrophobicity required for aerial growth and conidial dispersal; its expression is light-induced and clock-controlled.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0042243 asexual spore wall assembly | IMP PMID:1459460 The Neurospora circadian clock-controlled gene, ccg-2, is al... | NEW | Summary: Proposed new annotation. EAS builds the rodlet monolayer that forms the outer layer of the macroconidial (asexual spore) wall; GOA carries only the structural and localization terms, leaving the assembly process itself unannotated. Reason: Grounded in loss-of-function genetics rather than in vitro self-assembly. RIP inactivation of ccg-2/eas produces the eas phenotype with loss of rodlet fascicles, and transformation of an eas mutant with ccg-2 DNA restores surface rodlets - reciprocal mutant and complementation evidence that the gene product is required to assemble the outer layer of the asexual spore wall. The homologous A. nidulans hydrophobins rodA and dewA both carry GO:0042243 on comparable mutant evidence; grounding it here also supplies the evidence for the neu_eas annoton's process assertion in the conidiation module. Supporting Evidence: PMID:1459460 inactivation of the ccg-2 gene, by RIP, results in an eas phenotype including loss of rodlet fascicles PMID:1459460 transformation of an eas mutant strain with ccg-2 DNA results in phenotypic complementation, including restoration of surface rodlets |
| GO:0005199 structural constituent of cell wall | IEA GO_REF:0000002 | ACCEPT | Summary: Accept: structural constituent of cell wall. Reason: The InterPro hydrophobin signature that drives this IEA is corroborated by genetics for this specific protein - eas mutants lack rodlet fascicles and complementation restores them, so EAS is a structural component of the outer conidial wall layer rather than an enzyme or regulator acting on it. This is the term the core function rests on. Supporting Evidence: PMID:1459460 inactivation of the ccg-2 gene, by RIP, results in an eas phenotype including loss of rodlet fascicles |
| GO:0005576 extracellular region | IEA GO_REF:0000120 | ACCEPT | Summary: Accept: extracellular region. Reason: EAS has a predicted cleaved signal peptide (residues 1-26) and UniProt records it as Secreted on the strength of three experimental papers; it does its work outside the plasma membrane, assembling at the hydrophobic:hydrophilic interface. The location is broad but not wrong - the spore wall and fungal-type cell wall terms below refine it. |
| GO:0009277 fungal-type cell wall | IEA GO_REF:0000002 | ACCEPT | Summary: Accept: fungal-type cell wall. Reason: The rodlet layer is the outermost layer of the fungal-type wall of aerial cells, and EAS coats aerial hyphae as well as macroconidia - so this term, unlike spore wall, also covers the non-spore aerial surface where EAS is deposited. |
| GO:0031160 spore wall | IEA GO_REF:0000044 | ACCEPT | Summary: Accept: spore wall. Reason: The most specific and most useful of the four location terms - the rodlet fascicles EAS builds sit on the macroconidial surface, and their absence is exactly what the eas mutant phenotype scores. Independently supported by the three EXP rows below. |
| GO:0005576 extracellular region | EXP PMID:16537446 Structural basis for rodlet assembly in fungal hydrophobins. | ACCEPT | Summary: Accept: extracellular region. Reason: This paper solved the monomeric EAS structure and showed complete segregation of charged and hydrophobic residues on its surface - the architecture of a protein that functions at an air/water interface outside the cell, and the basis for the UniProt Secreted assignment citing it. Supporting Evidence: PMID:16537446 EAS forms a beta-barrel structure punctuated by several disordered regions and displays a complete segregation of charged and hydrophobic residues on its surface |
| GO:0005576 extracellular region | EXP PMID:18674544 The Cys3-Cys4 loop of the hydrophobin EAS is not required fo... | ACCEPT | Summary: Accept: extracellular region. Reason: This study measured the surface activity of EAS directly, showing that loop deletions leave both rodlet formation and surface activity intact - an assay that only makes sense for a protein acting at an extracellular interface. Supporting Evidence: PMID:18674544 deletion of up to 15 residues from this 25-residue loop does not impair rodlet formation or reduce the surface activity of the protein |
| GO:0005576 extracellular region | EXP PMID:22308366 Self-assembly of functional, amphipathic amyloid monolayers ... | ACCEPT | Summary: Accept: extracellular region. Reason: The self-assembly this paper characterises is explicitly interfacial - EAS polymerises at hydrophobic:hydrophilic interfaces into amphipathic monolayers, which places the assembled form outside the cell. Supporting Evidence: PMID:22308366 Self-assembly of EAS into fibrillar rodlets occurs spontaneously at hydrophobic:hydrophilic interfaces and the rodlets further associate laterally to form amphipathic monolayers |
| GO:0031160 spore wall | EXP PMID:16537446 Structural basis for rodlet assembly in fungal hydrophobins. | ACCEPT | Summary: Accept: spore wall. Reason: The paper's X-ray fibre diffraction on EAS rodlets ties the structural model to the actual rodlet polymer, and it frames class I hydrophobins as forming the monolayer on spore surfaces. Note the spore-wall placement itself rests on the older mutant genetics (PMID:1459460) rather than on in situ imaging here. Supporting Evidence: PMID:16537446 X-ray fiber diffraction data from EAS rodlets are consistent with our model |
| GO:0031160 spore wall | EXP PMID:18674544 The Cys3-Cys4 loop of the hydrophobin EAS is not required fo... | ACCEPT | Summary: Accept: spore wall. Reason: Works on EAS specifically as the N. crassa class I hydrophobin and characterises the rodlet monolayers that coat spore surfaces; the mutant series shows the rodlet-forming capability is robust to loop truncation, reinforcing that rodlet assembly is EAS's constitutive surface role. Supporting Evidence: PMID:18674544 we investigated the role of the Cys3-Cys4 loop in EAS, a class I hydrophobin from Neurospora crassa |
| GO:0031160 spore wall | EXP PMID:22308366 Self-assembly of functional, amphipathic amyloid monolayers ... | ACCEPT | Summary: Accept: spore wall. Reason: Identifies the region of EAS that drives rodlet assembly and shows the rodlets are the functional amyloid form deployed on the spore surface. The spore-wall localisation is inherited framing from the mutant genetics rather than newly demonstrated in this in vitro study, but it is not in doubt. Supporting Evidence: PMID:22308366 We have used site-directed mutagenesis and peptide experiments to identify the region of EAS that drives intermolecular association and formation of the cross-Ξ² rodlet structure |
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Download this section (compressed HTML)UniProt Q04571. Class I rodlet hydrophobin (clock-controlled gene 2). Neurospora variant, structural-output tier.
- Fungal hydrophobin required for the conidial rodlet layer / surface hydrophobicity; light-induced, clock-controlled. [file:NEUCR/eas/eas-uniprot.txt "encodes a fungal hydrophobin required for formation of the conidial"].
- Core MF GO:0005199 structural constituent of cell wall; all annotations ACCEPT. Analog of Aspergillus RodA/DewA.
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