ASF1 activation PI3K/AKT pathway regulates sexual and asexual development in filamentous ascomycete

Abstract

Sexual and asexual reproduction is ubiquitous in eukaryotes. PI3K/AKT signaling pathway can modulate sexual reproduction in mammals. However, this signaling pathway modulating sexual and asexual reproduction in fungi is scarcely understood. SeASF1, a SeH4 chaperone, could manipulate sexual and asexual reproduction of Stemphylium eturmiunum. SeDJ-1, screened from Se{Delta}asf1 transcriptome, was confirmed to regulate sexual and asexual development by RNAi, of which the mechanism was demonstrated by detecting transcriptional levels and protein interactions of SeASF1, SeH4 and SeDJ-1 by qRT-PCR, and Y2H, Co-IP and Pull-down, respectively. SeASF1 coupling SeH4 bound SeDJ-1 to arouse the sexual and asexual activity. In S. eturmiunum genome, SeDJ-1 was upstream while SeGSK3 was downstream in PI3K/AKT signaling pathway. Moreover, SeDJ-1 interacted with SePI3K or SeGSK3 in vivo and in vitro. Significantly, SeDJ-1 or SePI3K could effectively stimulate sexual activity alone, but SePI3K could recover the sexual development of SiSeDJ-1. Meanwhile, SeDJ-1-M6 was a critical segment for interaction of SeDJ-1 with SePI3K. SeDJ-1-M6 played a critical role in irritating sexual reproduction in SiSePI3K, which further uncovered the regulated mechanism of SeDJ-1. Summarily, SeASF1 coupling SeH4 motivates SeDJ-1 to arouse SePI3K involved in sexual reproduction. Thus, SeASF1 can activate PI3K/AKT signaling pathway to regulate sexual and asexual development in filamentous ascomycete.