Egy fork-head típusú transzkripciós faktor sejtosztódásban játszott szerepének elemzése
Title in English
Analysis of the role of a fork-head transcription factor in cell division
Panel
Cellular and Developmental Biology
Department or equivalent
Department of Genetics and Applied Microbiology (University of Debrecen)
Starting date
2005-01-01
Closing date
2008-12-31
Funding (in million HUF)
6.767
FTE (full time equivalent)
1.47
state
closed project
Final report
Results in Hungarian
A sejtosztódáshoz szukseges sok szaz gen periodikus mukodtetese, amelynek molekularis mechanizmusarol nagyon keveset tudunk. Azonban szamos rakos megbetegedes kialakulasaban megtalalhato ok a periodikusan mukodo genek szabalyozasanak hibaja, amely igy folyamatos aktivalast es kontrollalatlan osztodast eredmenyez. A kutatasi projekt soran egy, a periodikus transzkripcioban szerepet jatszo gént (sep1) vizsgaltunk elesztoben, kolcsonhato partnereket is azonositottunk, hogy jobban megismerjuk a molekularis mechanizmust. Kimutattuk, hogy a sep1 protein szabalyozasa sejtciklus fuggo foszforilacio/defoszforilacioval tortenik es azonositottuk a protein foszforilaciohoz szukseges regioit. Azonositottunk kolcsonhato partnereket is. Egy fork head tipusu regulatort (fkh2), és funkciojat kimutattuk a sejosztodas szabalyozasaban. Továbbá a transzkripcios szabalyozashoz az elesztotol az emberig szukseges Mediator komplexet, kimutattuk sejciklusfuggo kotodeset sep1 fuggo promoteren, időben egyutt a sep1 kotodesevel. Tovabba szamos Mediator alegysegben mutans sejt nem kepes sep1 target genek megfelelo aktivalasara. A kapott eredmenyek alapjan feltetelezzuk, hogy a sep1p aktivitasa a foszforilacioval szabalyozodik, sejtciklus fuggő módon kotodik a promoterhez, kolcsonhat a fkh2-vel es a Mediator komplex-el, amelyek reven a transzkripcio aktivalódik. A tovabbiakban a protein-protein kolcsonhatasok reszletes vizsgalata reven szeretnenk jobban megismerni a folyamat molekularis mechanizmusat.
Results in English
Acomplishment of the cell division cycle requires the periodic regulation of hundreds of genes in eukaryotic cells. Although defects in the periodic regulation of some of these cell cycle genes are major causes of development of various cancers, molecular mechanism of periodic transcription is poorly understood.
In this project, we focused on the characterization of sep1, a regulator of periodic transcription of genes required for mitosis and cytokinesis. We found that sep1 activity is regulated by periodic phosphorylation/dephosphorylation and that elimination of C-terminal regions is critical for phosphorylation and target activation. We also identified and characterized functionally interacting partners of sep1, namely fkh2, a fork head regulator and we showed its function in the regulation of mitosis, similarly to sep1. We also identified that periodic transcription requires the evolutionary conserved Mediator complex, and deletion of Mediator subunits impair transcription of sep1 targets . The complex binds to sep1 target promoter in its binding attached to sep1p binding and Mediator binding is lost in sep1 deleted cells. We propose a model, where sep1 activity is regulated by periodic phosphorylation which probably enables the recruitment of the Mediator complex to bring about transcription. In further work, we focus on to study protein-protein interactions of sep1, fkh2 and Mediator to understand the molecular mechanism of periodic transcription at mitosis.
Lee, K. M.,Miklos, I. Du, H. Watt, S. Szilagyi, Z. Saiz, J. E. Madabhushi, R. Penkett, C. J. Sipiczki, M. Bahler, J. Fisher, R. P.: Impairment of the TFIIH-associated CDK-activating kinase selectively affects cell cycle-regulated gene expression in fission yeast, Mol Biol Cell, 16:2734-45, 2005
GYULA BATTA, RÉKA NAGY, ZSUZSA ANTUNOVICS, IDA MIKLÓS, ZSOLT SZILÁGYI, JÜRG BAHLER, MATTHIAS SIPICZKI: TRANSCRIPTIONAL REGULATION BY MEDIATOR SUBUNITS IN SCHIZOSACCHAROMYCES POMBE, Acta Microbiologica et Immunologica Hungarica, 53 (3), pp. 247, 2006
ZSOLT SZILÁGYI, MATTHIAS SIPICZKI: THE ROLE OF PHOSPHORYLATION OF THE SEP1 FORK HEAD TRANSCRIPTION FACTOR IN THE REGULATION OF CYTOKINESIS IN FISSION YEAST, Acta Microbiologica et Immunologica Hungarica, 53 (3), pp. 348, 2006
Miklos I, Szilagyi Z, Watt S, Zilahi E, Batta G, Antunovics Z, Enczi K, Bähler J, Sipiczki M.: Genomic expression patterns in cell separation mutants of Schizosaccharomyces pombe defective in the genes sep10 ( + ) and sep15 ( + ) coding for the Mediator subunits Me, Mol Genet and Genomics, 279:225-38, 2008
Szilagyi, Z. Batta, G. Enczi, K. Sipiczki, M.: Characterisation of two novel fork-head gene homologues of Schizosaccharomyces pombe: their involvement in cell cycle and sexual differentiation, Gene, 348:101-9, 2005
