Transcription initiation by RNA polymerase II (pol II) is very often the major regulatory step in differential gene expression in eukaryotic cells, and as such, has important roles in normal cell growth and division, the proper response of a cell to signaling pathways, and in the development and differentiation of multicellular organisms. It is therefore fundamental that we fully understand the basic components of the transcription machinery, their mechanism of action, and how their activities are regulated.

 To identify general transcription factors or their regulators in vivo, our studies rely upon a highly successful genetic selection to identify mutations that increase basal transcription. (see BUR selection figure for details)  Using this selection we identified six genes, designated BUR1 through BUR6. All of the BUR genes have now been cloned, and the results place these genes right at the heart of the transcription machinery. BUR1 encodes a cyclin-dependent protein kinase, and BUR2 encodes a cyclin required for Bur1 kinase activity. We demonstrated that the Bur1-Bur2 kinase complex can phosphorylate RNA polymerase II and that it has an essential role during transcription elongation. BUR3 and BUR6 each regulate the TATA-binding protein (TBP), although by different mechanisms: BUR3 encodes an ATPase that dissociates TBP from the promoter, while Bur6 blocks interactions between TBP and the other general transcription factors.  BUR1, BUR2, BUR3, and BUR6 thus directly regulate TBP and pol II, the two most central components of the transcription machinery.

Our recent genetic analysis revealed exciting links between Bur1 and histone methylation;  strains that contain a deletion of BUR1 are nearly dead, but the poor growth of bur1 deletion strains is suppressed by mutations in SET2, which encodes a histone methylase that is also implicated in transcription elongation.  Furthermore, the Bur1-Bur2 complex is required for the progression of histone H3 from a di-methylated to a tri-methylated form.  Genetics has also provided insight into a link between BUR3 (also known as MOT1) and the SUMO pathway.  The SUMO pathway is a highly conserved yet poorly understood system that results in the covalent post-translational modification of many proteins.  More specifically, we have identified two genes (SLX5 and SLX8) that are new components or regulators of the SUMO pathway.  We are currently studying the role of these proteins in the SUMO pathway and how they impact on Mot1 and regulation of TBP.

 We have recently begun a new large-scale project to begin genome-wide analysis of gene overexpression.  We have constructed a new plasmid library that has become a major tool that enabling us to systematically overexpress every gene and examine the phenotypic consequences.  This library, which currently covers ~98% of the genome, is being used to explore genes involved in transcriptional regulation, the SUMO pathway, drug sensitivity, and other cellular processes.

Lab Publications:

Jones, G.M., Stalker, J., Humphray, S., West, A., Cox, T., Rogers, J., Dunham, I., and Prelich, G. (2008) A systematic library for comprehensive overexpression screens in Saccharomyces cerevisiae.  Nature Methods 5: 239-241.

Chu, Y., Simic, R., Warner, M.H., Arndt, K.M., and Prelich, G. (2007) Regulation of histone modification and cryptic transcription by the Bur1 and Paf1 complexes.  EMBO J. 26: 4646-4656.

Chu, Y., Sutton, A., Sternglanz, R., and Prelich, G. (2006) The Bur1 cyclin-dependent protein kinase is required for the normal pattern of histone methylation by Set2.  Mol. Cell. Biol. 26: 3029-3038.

Wang, Z., Jones, G.M., and Prelich, G. (2006) Genetic analysis connects SLX5 and SLX8 to the SUMO pathway in Saccharomyces cerevisae.  Genetics 172: 1499-1509.

Cang, Y. and G. Prelich. (2002)  Direct stimulation of transcription by Negative Cofactor 2 (NC2) through TATA-binding protein (TBP).  Proc. Natl. Acad. Sci. USA  99: 12727-12732.

Prelich, G.  (2002)  The RNA polymerase II CTD kinases: emerging clues to their function.  Eukaryotic Cell 1:153-162.

Yao, S. and G. Prelich.  (2002)  Activation of the Bur1-Bur2 cyclin-dependent kinase complex by Cak1.  Mol. Cell. Biol.  22: 6750-6758.

Murray, S., Udupa, R., Yao, S., Hartzog, G., and Prelich, G.  (2001)  Phosphorylation of the RNA polymerase II Carboxy-terminal domain by the Bur1 cyclin-dependent kinase. Mol. Cell. Biol. 21:4089-4096.

Yao, S., Neiman, A., and Prelich, G.  (2000) BUR1 and BUR2 encode a divergent cyclin-dependent kinase-cyclin complex important for transcription in vivo. Mol. Cell. Biol. 20: 7080-7087.

Prelich, G. (1999) Suppressor mechanisms: themes from variations. Trends in Genetics 15: 261-266

Cang, Y., Auble, D.T., and G. Prelich. (1999) A new regulatory domain on the TATA-binding protein. EMBO J. 18: 6662-6671.

Prelich, G. (1997) Saccharomyces cerevisiae BUR6 encodes a DRAP1/NC2a homolog that has both positive and negative roles in transcription in vivo. Mol. Cell. Biol. 17: 2057-2065.

Prelich, G. and Winston, F. (1993) Mutations that suppress the deletion of an Upstream Activating Sequence in yeast: involvement of a protein kinase and histone H3 in repressing transcription in vivo. Genetics 135: 665-676.