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Mary Bryk

Bryk, Mary
Mary Bryk
Associate Professor
BioBio / Room 334A
Undergraduate Education
B.Sc. Cornell University (1985)
Graduate Education
M.S. Albany Medical College (1991)
Ph.D. Albany Medical College (1994)
Postdoc. Wadsworth Center, Albany (1995-1997)
Harvard Medical School, Boston (1997-2002)
Joined Texas A&M in 2002

Transcriptional Regulation/Chromatin Structure

How cells regulate gene expression is fundamental to most aspects of biology. My laboratory is interested in the regulation of gene expression at active and inactive regions of the yeast genome. We identify proteins that regulate transcription using classic and modern genetic techniques. Then, we investigate how these factors influence transcription and chromatin structure using a combination of genetic, molecular, and biochemical methods.
Our current research addresses complex questions regarding the role of histone methylation in the regulation of transcription of the HIS3 gene. In budding yeast, there is a single lysine methyltransferase, Set1, that catalyzes mono-, di- and tri-methylation of the fourth residue, lysine 4, of histone H3. Set1 is a great model to study because it generates three chromatin marks and each mark is not equivalent. We exploit novel genetic variants of the conserved Set1 protein that differentially affect methylation of lysine 4 (K4) of histone H3 (e.g. abolish H3K4 tri-methylation while keeping H3K4 mono-methylation intact). Studies using these Set1 mutants provide insights into the roles of different H3K4 methyl marks in transcription by Pol II. We are also investigating the role of antisense transcription in regulation of the HIS3 gene. This research is expected to define new paradigms in gene regulation.
Our research on silent chromatin focuses on Pol II-transcribed genes located in the ribosomal DNA (rDNA) locus. We use Pol II-transcribed genes to characterize mechanisms that regulate silent chromatin. Silent chromatin not only represses Pol II transcription but also genetic recombination. Alterations in rDNA recombination reduce the stability of the rDNA locus and the yeast genome, leading to premature aging and cell death.
The goal of my lab is to learn about mechanisms that regulate Pol II transcription and chromatin structure. We use several methods, such as growth assays, RNA analysis, chromatin immunoprecipitation, mutagenesis and genetic screens, to characterize Pol II transcription and chromatin function. Our findings will increase our understanding of how chromatin dynamics influence gene expression and genome integrity. Many of the factors we study have homologues in human cells indicating that our discoveries may provide insights into mechanisms that regulate gene expression in higher eukaryotes.

Recent Publications

  1. Williamson, K, Schneider, V, Jordan, RA, Mueller, JE, Henderson Pozzi, M, Bryk, M et al.. Catalytic and functional roles of conserved amino acids in the SET domain of the S. cerevisiae lysine methyltransferase Set1. PLoS ONE. 2013;8 (3):e57974.
    doi: 10.1371/journal.pone.0057974. PubMed PMID:23469257. PubMed Central PMC3585878.

  2. Blank, HM, Li, C, Mueller, JE, Bogomolnaya, LM, Bryk, M, Polymenis, M et al.. An increase in mitochondrial DNA promotes nuclear DNA replication in yeast. PLoS Genet. 2008;4 (4):e1000047.
    doi: 10.1371/journal.pgen.1000047. PubMed PMID:18404213. PubMed Central PMC2289842.

  3. Li, C, Mueller, JE, Elfline, M, Bryk, M. Linker histone H1 represses recombination at the ribosomal DNA locus in the budding yeast Saccharomyces cerevisiae. Mol. Microbiol. 2008;67 (4):906-19.
    doi: 10.1111/j.1365-2958.2007.06101.x. PubMed PMID:18179596. .

  4. Mueller, JE, Li, C, Bryk, M. Isw2 regulates gene silencing at the ribosomal DNA locus in Saccharomyces cerevisiae. Biochem. Biophys. Res. Commun. 2007;361 (4):1017-21.
    doi: 10.1016/j.bbrc.2007.07.140. PubMed PMID:17689493. PubMed Central PMC2083704.

  5. Mueller, JE, Bryk, M. Isw1 acts independently of the Isw1a and Isw1b complexes in regulating transcriptional silencing at the ribosomal DNA locus in Saccharomyces cerevisiae. J. Mol. Biol. 2007;371 (1):1-10.
    doi: 10.1016/j.jmb.2007.04.089. PubMed PMID:17561109. PubMed Central PMC1995125.

  6. Li, C, Mueller, JE, Bryk, M. Sir2 represses endogenous polymerase II transcription units in the ribosomal DNA nontranscribed spacer. Mol. Biol. Cell. 2006;17 (9):3848-59.
    doi: 10.1091/mbc.e06-03-0205. PubMed PMID:16807355. PubMed Central PMC1593162.

  7. Mueller, JE, Canze, M, Bryk, M. The requirements for COMPASS and Paf1 in transcriptional silencing and methylation of histone H3 in Saccharomyces cerevisiae. Genetics. 2006;173 (2):557-67.
    doi: 10.1534/genetics.106.055400. PubMed PMID:16582434. PubMed Central PMC1526511.

  8. Bryk, M, Briggs, SD, Strahl, BD, Curcio, MJ, Allis, CD, Winston, F et al.. Evidence that Set1, a factor required for methylation of histone H3, regulates rDNA silencing in S. cerevisiae by a Sir2-independent mechanism. Curr. Biol. 2002;12 (2):165-70.
    . PubMed PMID:11818070. .

  9. Briggs, SD, Bryk, M, Strahl, BD, Cheung, WL, Davie, JK, Dent, SY et al.. Histone H3 lysine 4 methylation is mediated by Set1 and required for cell growth and rDNA silencing in Saccharomyces cerevisiae. Genes Dev. 2001;15 (24):3286-95.
    doi: 10.1101/gad.940201. PubMed PMID:11751634. PubMed Central PMC312847.

  10. Bryk, M, Banerjee, M, Conte, D Jr, Curcio, MJ. The Sgs1 helicase of Saccharomyces cerevisiae inhibits retrotransposition of Ty1 multimeric arrays. Mol. Cell. Biol. 2001;21 (16):5374-88.
    doi: 10.1128/MCB.21.16.5374-5388.2001. PubMed PMID:11463820. PubMed Central PMC87260.

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