Antagonistic regulation of cyclin expression by the bZIP transcription factors Pcr1 and Atf1 during G2/M transition

Abstract

The transcription factor Atf1 is known to promote cell survival during various stress conditions in Schizosaccharomyces pombe by activating the expression of appropriate genes. It can also activate transcription of other important genes responsible for cell cycle progression. An Atf1-dependent increase in the expression of cell division promoting genes will oppose activation of checkpoints necessary to ensure repairs and cell survival during stress. Hence, selective inhibition of the cell cycle-related functions of Atf1 would be indispensable for cellular survival during stress. Here we present evidence in favour of selective inhibition of Atf1's ability to activate cdc13+ transcription. We show that the transcription factor Pcr1 can specifically inhibit the recruitment of Atf1 on cdc13 promoter and thereby prevent Atf1-mediated mitotic acceleration. We also show that this opposition of Atf1 functions by Pcr1 extends to the G1-S transition event as well. Altogether these results suggest a previously unknown antagonistic function of Atf1 and Pcr1 in regulating Cdc13 expression during cell cycle progression.

Dataset describing the genome wide effects on transcription resulting from alterations in the relative levels of the bZIP transcription factors Atf1 and Pcr1 in Schizosaccharomyces pombe

“…Studies done in our lab have established Pcr1 to be important in combating stress responses and to have contrasting outcomes on cell cycle progression [1] . In this study, we used genetic manipulations to vary the relative levels of Atf1 and Pcr1 in S. pombe cells.…”

Genetic Interaction of Global Regulators AflatfA and AflatfB Mediating Development, Stress Response and Aflatoxins B1 Production in Aspergillus flavus

“…In Schizosaccharomyces pombe, Atf1 lowers the transition barrier for nucleosome-mediated establishment of heterochromatin, activates the fbp1 gene transcription induced upon glucose starvation and modulates meiotic recombination and heterochromatin formation [5][6][7][8][9][10]. Atf1 frequently forms heterodimers with other bZIP TF Pcr1, and the interaction of Atf1 and Pcr1 regulates not only stress response genes but also cyclin expression during G2/M transition [8,11,12]. Moreover, Atf1 is a target for the ubiquitin-proteasome system and that its degradation is dependent upon an SCF E3 ligase containing the F box protein Fbh1 [13].…”