A novel family of cyclic oligopeptides derived from ribosomal peptide synthesis of an in planta-induced gene, gigA, in Epichloë endophytes of grasses.
Fungal Genet Biol
; 85: 14-24, 2015 Dec.
Article
in En
| MEDLINE
| ID: mdl-26519220
ABSTRACT
Fungal endophytes belonging to the genus Epichloë form associations with temperate grasses belonging to the sub-family Poöideae that range from mutualistic through to pathogenic. We previously identified a novel endophyte gene (designated gigA for grass induced gene) that is one of the most abundantly expressed fungal transcripts in endophyte-infected grasses and which is distributed and highly expressed in a wide range of Epichloë grass associations. Molecular and biochemical analyses indicate that gigA encodes a small secreted protein containing an imperfect 27 amino acid repeat that includes a kexin protease cleavage site. Kexin processing of GigA liberates within the plant multiple related products, named here as epichloëcyclins, which we have demonstrated by MS/MS to be cyclic peptidic in nature. Gene deletion of gigA leads to the elimination of all epichloëcyclins with no conspicuous phenotypic impact on the host grass, suggesting a possible bioactive role. This is a further example of a ribosomal peptide synthetic (RiPS) pathway operating within the Ascomycetes, and is the first description of such a pathway from a mutualistic symbiotic fungus from this Phylum.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Fungal Proteins
/
Epichloe
/
Endophytes
/
Poaceae
Language:
En
Journal:
Fungal Genet Biol
Journal subject:
GENETICA
/
MICROBIOLOGIA
Year:
2015
Document type:
Article