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Laboratory of gene expression regulation

Principal investigator : Dr. Petr Folk

The Laboratory is interested 1) in the mechanisms of splicing regulation and the relationship between splicing and transcription using yeast as model organisms, and 2) in the functioning of CSL (CBF1/ RBP-Jkappa/Suppressor of Hairless/LAG-1) transcription factor family orthologs in yeast.

1) Most eukaryotic protein-coding transcripts contain introns, which vary in number, lenit, and position along the transcript body. Splicing - the process of intron removal is regulated by transcription factor atracted to promoters as well as tightly linked to RNA transcription by RNA polymerase II as it translocates along each gene. Both Saccharomyces cerevisiae and Schizosaccharomyces pombe are used to study evolutionarily conserved regulatory factors of the synthesis and maturation phases of RNA transcript production. Introns in S. cerevisiae are relatively few (less than ~5% of genes) and short; the spliceosomes still contain an almost complete array of splicing factors as compared to other organisms (S. pombe or higher eukaryotes). The study of splicing factors in an organism with reduced intronome complexity should help to identify interactions that link splicing to other gene expression processes.

Recently, we have identified a single nucleotide substitution in the region between branch point (BP) and 3’ splice site (3’ss) of S. cerevisiae COF1 intron, which dramatically impaired its splicing. RNA structure prediction and in-line probing showed that this mutation disrupted a stem in the BP-3’ss region. Analyses of various modifications in predicted stem revealed that this structure brought about the reduction of BP to 3’ss distance and also masked potential 3’splice sites upstream the used one. We also demonstrated that such secondary structure may support splicing almost all distant BP introns in S. cerevisiae and for selected examples in several other Saccharomycotina species, suggesting the existence of a general pre-mRNA structure based mechanism of 3’ss recognition.

2) CSL (CBF1/RBP-Jkappa/Suppressor of Hairless/LAG-1) transcription factor family comprises of evolutionarily conserved proteins that in animals mediate the transcriptional responses to the Notch signalling, which is crucial for development. In addition to this role, metazoan CSL proteins also have Notch-independent functions that are poorly understood. We have found that CSL proteins also exist in some fungi, i.e., in organisms lacking the Notch pathway. In the fission yeast Schizosaccharomyces pombe, there are two CSL paralogs, Cbf11 and Cbf12 which have antagonistic roles in the regulation of cell adhesion and the coordination of cell cycle events.

Our recent experiments indicate that Cbf11 and Cbf12 also play important roles in genome stability and associated checkpoints. Our goals is to identify the step in DNA-integrity checkpoint pathways in which the CSL factors function, and to understand the genome-wide roles of CSL transcriptional control and DNA binding during cell proliferation and genotoxic stress. Our research should afford unique insight into novel aspects of CSL function, bringing together two important signalling pathways with fundamental relevance for carcinogenesis: CSL-dependent transcriptional control and DNA-integrity checkpoints.

Contact information:


Doc. RNDr. Petr Folk, CSc. petr.folk@natur.cuni.cz

Doc. RNDr. František Půta, CSc. frantisek.puta@natur.cuni.cz

RNDr. Martin Převorovský, Ph.D. martin.prevorovsky@natur.cuni.cz (projekty S. pombe)

Mgr. Kateřina Abrhámová, Ph.D. katerina.abrhamova@natur.cuni.cz (projekty S. cerevisiae)

Lab location: Viničná 5, 1. basement (right), door n. S08; tel. 22195 1785


More informations on czech version of our website:Laboratoř regulace genové exprese




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