The Prr1 response regulator is essential for transcription of ste11 + and for sexual development in fission yeast

Abstract

Schizosaccharomyces pombe expresses a putative transcription factor, named Prr1, which is intriguing in the sense that it contains a bacterial type of phospho-accepting receiver domain, preceded by a mammalian heat shock factor (HSF2)-like DNA-binding domain. The receiver domain is most probably involved in an as yet unidentified histidine-to-aspartate (His-to-Asp) phosphorelay pathway in S. pombe. In this study, the structure, function, and cellular localization of Prr1 were assessed in the context of oxidative stress and His-to-Asp phosphorelay. As the most intriguing result of this study, we found that Prr1 is essential not only for the expression of genes induced by oxidative stress (e.g., ctt1+ and trr1+), but also for the expression of ste11+, which in turn is responsible for the expression of a variety of genes required for sexual development. Accordingly, Prr1-deficient cells are not only hypersensitive to oxidative stress, but also severely defective in conjugation and/or spore formation. These results suggested that the transcription factor Prr1 plays a pivotal role in an as yet unknown signal transduction pathway that is implicated in sexual differentiation. These findings are discussed with special reference to the well-characterized transcription factors Pap1 and Atf1 of S. pombe.

The SskA and SrrA Response Regulators Are Implicated in Oxidative Stress Responses of Hyphae and Asexual Spores in the Phosphorelay Signaling Network ofAspergillus nidulans

“…12) The role of SrrA in A. nidulans is also analogous to those reported previously for Skn7p (S. cerevisiae) 29) and Prr1 (S. pombe), 30,46) and Candida albicans). 47,48) This suggests that a characteristic stress-responsive signaling pathway consisting of the prokaryotic and the eukaryotic signaling modes is highly conserved within a variety of species belonging to fungi.…”

“…It has been found for Prr1 of S. pombe that this SrrA ortholog binds to a DNA sequence with an HSF-consensus nGAAnn(A/T)TC(G/T). 46) Taking all this together, it may be assumed that SrrA activates catB transcription by binding directly to its promoter region. It may also be assumed that the DNA-binding activity of SrrA is modulated through phosphorylation by certain upstream HKs.…”

Oxidative stress response pathways: Fission yeast as archetype

“…In addition to its Pap1-supporting role (Chen et al, 2008;Calvo et al, 2012), Prr1 induces stress genes independently of Sty1 (Ohmiya et al, 1999(Ohmiya et al, , 2000 and it supports the induction of Atf1-dependent genes (Calvo et al, 2012;Greenall et al, 2002). No orthologous protein of Prr1 exists in humans (Penkett et al, 2006), while one of the Prr1 orthologs in budding yeast, SKN7, assists the YAP1 TF (i.e.…”

His-to-Asp Phosphorelay Circuitry for Regulation of Sexual Development inSchizosaccharomyces pombe

“…At intervals, total RNA samples were prepared from the cells, as described previously. 17) After denaturation with formamideformaldehyde, RNA (10 mg W lane) was fractionated on a 1.4z agarose gel containing formaldehyde, and blotted in alkaline solution onto Hybond-N+ (Amersham). Hybridization was carried out with appropriated 32 P-labelled probes at 659 C for 2 hours in a hybridization kit, as recommended by the supplier (Amersham).…”

“…17) With regard to Mcs4, the results of extensive studies supported the view that it plays a role in mitotic cell cycle control, and also that it appears to function immediately upstream of the S. pombe stress-activated Sty1-mitogen-activated protein kinase (MAPK) cascade. [18][19][20][21][22] Then, an upstream HPt factor (named Spy1, also known as Mpr1) was discovered, demonstrating that this phosphotransfer intermediate, together with Mcs4, plays a role in control of the timing of mitotic initiation (i.e., G2 W M transition), and also in adaptive responses to oxidative stress.…”