Die Funktion von TTF-I bei der Transkriptions-Termination in Chromatin und in der Organisation der Chomatinstruktur der rDNA Terminatoren
Zusammenfassung der Projektergebnisse
TTF-I plays a fundamental role in transcription termination and the activation of transcription initiation in chromatin. Transcription termination and the chromatin remodeling event at the rDNA promoter, a prerequisite for transcription initiation, requires auxiliary factors to exert this processes. Therefore Petr Jansa, in Ingrid Grummts laboratory, started a yeast two hybrid screen for TTF-I interacting proteins (Tip). One of these proteins (Tip5) showed a modular organization related to Acfl and WSTF, proteins that have been associated with chromatin structure and chromatin regulation. Tip5 is a nucleolar protein, co-lucalizing with the RNA polymerase I transcription factor UBF. Ralf Strohner purified a Tip5 containing protein complex with a molecular mass of 800 kDa, containing the ATPase Snf2H as a second subunit. This complex, termed NoRC (Nucleolar Remodeling Complex), belongs to the family of ISWI type chromatin remodeling complexes and is able to induce ATP-dependent nucleosome remodeling.
Projektbezogene Publikationen (Auswahl)
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Ciapier, C. R., Längst, G., Corona, D. F., Becker, P. B., and Nightingale, K. P. (2001). Critical role for the histone H4 N terminus in nucleosome remodeling by ISWI, Mol Cell Biol 21, 875-883.
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Eberharter, A., Ferrari, S., Längst, G., Straub, T., Imhof, A., Varga-Weisz, P., Wilm, M., and Becker, P. B. (2001). Acfl, the largest subunit of CHRAC, regulates ISWI-induced nucleosome remodeling, Embo J 20, 3781-3788.
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Längst, G., and Becker, P. B. (2001a). ISWI Induces Nucleosome Sliding on Nicked DNA, Mol Cell 8, 1085-1092.
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Längst, G., and Becker, P. B. (2001b). Nucleosome mobilization and positioning by ISWI-containing chromatin- remodeling factors, J Cell Sei 114, 2561-2568.
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Strohner, R., Nemeth, A., Jansa, P., Hof mann-Rohrer, U., Santoro, R., Längst, G., and Grummt, I. (2001). NoRC--a novel member of mammalian ISWI-containing chromatin remodeling machines, Embo J 20, 4892-4900.
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Bilbao-Cortes, D., Hetzer, M., Längst, G., Becker, P.B. and Mattaj, I.W. (2002). Ran binds to chromatin by two distinct mechanisms. Curr Biol., 12( 13), 1151 -1156.
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Bonaldi, T, Längst*, G, Strohner, R., Becker, P.B. and Bianchi, M. (2002) The DNA chaperone HMGB1 facilitates ACF/CHRAC-dependent nucleosome sliding. Embo J 21, 6865-6873.
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Bouazoune, K., Mitterweger, A., Längst, G., Imhof, A., Akhtar, A., Becker, P.B. and Brehm, A. (2002). The dMi-2 chromodomains are DNA binding modules important for ATP-dependent nucleosome mobilization. Embo J, 21, 2430-2440.
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Eberharter, A., Längst, G. and Becker, P.B. (2003) A nucleosome sliding assay for chromatin remodeling factors. Methods in Enzymology 377, 344-353.
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Chin, J., Längst, G., Becker, P.B. and Widom, J. (2004) Fluorescence Anisotropy Assays for Analysis of ISWI-DNA and ISWI-Nucleosome Interactions. Methods in Enzymology 376, 3-16.
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Längst, G. and Becker, P.B. (2004) Nucleosome remodeling - One mechanism, many phenomena? Biochim Biophys Acta. 1677(l-3):58-63.
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Nemeth, A. and Längst, G. (2004). Chromatin higher order structure: Opening up chromatin for transcription. Brief. Funct. Gen. Prot. 2(4), 334-343
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Strohner, R., Nemeth, A., Nightingale, K.P., Grummt, I-, Becker, P.B. and Längst, G. (2004). Recruitment of the nucleolar remodeling complex NoRC establishes rDNA silencing. Mol Cell Biol, 24(4), 1791-1798
