The novel ER membrane protein PRO41 is essential for sexual development in the filamentous fungus Sordaria macrospora

Abstract

SummaryThe filamentous fungus Sordaria macrospora develops complex fruiting bodies (perithecia) to propagate its sexual spores. Here, we present an analysis of the sterile mutant pro41 that is unable to produce mature fruiting bodies. The mutant carries a deletion of 4 kb and is complemented by the pro41 open reading frame that is contained within the region deleted in the mutant. In silico analyses predict PRO41 to be an endoplasmic reticulum (ER) membrane protein, and a PRO41-EGFP fusion protein colocalizes with ER-targeted DsRED. Furthermore, Western blot analysis shows that the PRO41-EGFP fusion protein is present in the membrane fraction. A fusion of the predicted N-terminal signal sequence of PRO41 with EGFP is secreted out of the cell, indicating that the signal sequence is functional. pro41 transcript levels are upregulated during sexual development. This increase in transcript levels was not observed in the sterile mutant pro1 that lacks a transcription factor gene. Moreover, microarray analysis of gene expression in the mutants pro1, pro41 and the pro1/41 double mutant showed that pro41 is partly epistatic to pro1. Taken together, these data show that PRO41 is a novel ER membrane protein essential for fruiting body formation in filamentous fungi.

Circadian rhythms of superhelical status of DNA in cyanobacteria

“…In S. elongatus, the activities of essentially all promoters are rhythmically orchestrated, whereas in eukaryotes, microarray analyses suggest that only Ϸ5-15% of genes display circadian rhythms of mRNA abundance (3)(4)(5)(6)(7)(8)(9)(10)(11). Although microarrays are informative, this technique is not sensitive to small changes in mRNA abundance and is not a quantitative measure of rhythmic transcriptional activity for mRNAs that are either very unstable or very stable.…”

Three α-Subunits of Heterotrimeric G Proteins and an Adenylyl Cyclase Have Distinct Roles in Fruiting Body Development in the Homothallic Fungus Sordaria macrospora

“…Moreover, developmental defects are immediately apparent in this self-fertile fungus without the necessity of fertilization (Pö ggeler et al 2006a). To date, several S. macrospora pro mutants that develop protoperithecia but no perithecia have been generated and characterized, thereby revealing essential components of fruiting body development Nowrousian et al 1999Nowrousian et al , 2007aPö ggeler and Kü ck 2004;Kü ck 2005;Engh et al 2007). In addition, despite the fact that S. macrospora completes the sexual cycle without a mating partner, two pheromone-precursor (ppg1 and ppg2) and two pheromonereceptor genes (pre1 and pre2) were shown to be involved in sexual development (Pö ggeler and Kü ck 2000; Mayrhofer and Pö ggeler 2005;Mayrhofer et al 2006;Pö ggeler et al 2006b).…”

Circadian rhythmicity mediated by temporal regulation of the activity of p38 MAPK

“…10). To date, Ͼ180 ccgs have been identified in N. crassa (10)(11)(12)(13)(14), including genes associated with rhythms in asexual spore development (conidiation; ref. 15), metabolism (16), pheromone production (17), and stress responses (18).…”