Molecular characterization of the Pri3 gene encoding a cysteine-rich protein, specifically expressed during fruiting initiation within the Agrocybe aegerita complex

Abstract

Coding and regulating sequences of Pri3 (a novel gene specifically expressed in both nucleus types of dikaryons during fruiting initiation) were compared within nine strains of the Agrocybe aegerita complex originating from Europe, Asia and Latin America. Highly homologous coding sequences were found; and the 95-amino-acid-long PRI3 deduced proteins all shared eight cysteines and eight glycines, a putative signal peptide suggesting an extra-cellular localization, a protein kinase C site (T(70)) and a cAMP-dependent kinase site (S(74)). The PRI3 proteins presented no significant homologies with already known proteins and constitute a new class of small cysteine-rich proteins. Within the 5' uncoding regions, two leader introns and a putative upstream regulating sequence resembling the QA1-F activator site were highly conserved. Comparison of the gene sequences within the A. aegerita complex suggested a divergent evolution of the European and Asian/Latin American groups of genes.

The genome sequence of the commercially cultivated mushroom Agrocybe aegerita reveals a conserved repertoire of fruiting-related genes and a versatile suite of biopolymer-degrading enzymes

“…The last group of FRGs is made up by four genes (Table 2 ), which were transcriptionally induced during fruit body formation of the dikaryotic A. aegerita wild type strain SM51 (=WT-1) [ 79 ]. According to the prediction A. aegerita AAE-3 has homologs for each of these FRGs (Table 2 ).…”

Opposing developmental functions of Agrocybe aegerita galectin (AAL) during mycelia differentiation

“…Leader introns have been characterized in 5 0 non-coding sequences of cgl1, cgl2 (Boulianne et al 2000) and A.a-Pri4 gene from Agrocybe aegerita (Sirand-Pugnet et al 2003). Two leader introns in the Pri3 gene from A. aegerita primordia were recently described (Sirand-Pugnet & Labarere 2002). We hypothesize that the leader introns of aal gene might contribute to the high-level and regulated expression of AAL during fruiting body development.…”

“…Aa-Pri2 is a single copy gene that encodes a LEU zipper rich hydrophobic protein (Santos & Labarere 1999). Aa-Pri3 encodes a cysteinerich protein (Sirand-Pugnet & Labarere 2002). Aa-Pri4 gene, with a CT rich leader intron in the 5 0 uncoding region, has been characterized (Sirand-Pugnet et al 2003).…”

The SC15 protein of Schizophyllum commune mediates formation of aerial hyphae and attachment in the absence of the SC3 hydrophobin

“…brackets and mushrooms) by homobasidiomycetes is a very complex but poorly understood developmental process. A role for the SC7 and SC14 genes of S. commune (Schuren et al ., 1993a), the galectin genes of Coprinus cinereus (Cooper et al ., 1997) and pri3 of Agrocybe aegerita (Sirand‐Pugnet and Labarère, 2002) has been proposed on basis of their expression. However, hydrophobins are so far the only secreted proteins that by gene deletions have been shown to be instrumental in formation of fruiting bodies (van Wetter et al ., 2000a).…”