• Scientist , Molecular Medicine Program, Ottawa Health Research Institute
• Assistant Professor , University of Ottawa, Department of Medicine, Division of Hematology
• Canadian Research Chair (Tier 2) in The Regulation of Gene Expression

Biographical Sketch

Dr. Brand received her Ph.D. in Molecular Biology from the Universite Louis Pasteur. During her thesis training, Dr. Brand worked in the laboratory of Dr. Laszlo Tora at the Institut de Genetique et de Biologie Moleculaire et Cellulaire (Strasbourg, France), where she isolated and functionally characterized the “ TBP -Free TAF-containing Complex” (TFTC). Then, she joined the laboratory of Dr. Mark Groudine at the Fred Hutchinson Cancer Research Center (Seattle, WA) as a post-doctoral fellow to study the regulation of transcription at the ?-globin locus during erythroid differentiation. During that time, she collaborated with the mass spectrometry group directed by Dr. Ruedi Aebersold at the Institute for Systems Biology (Seattle, WA) in order to apply the recently developed ICAT technique of quantitative proteomics to study ?-globin transcription. At the OHRI , Dr. Brand's group continues to use quantitative proteomics to examine mechanisms involved in regulating gene expression.

Research Interest

Regulation of gene expression during hematopoiesis

Keywords

Chromatin, Transcription, ?-globin locus, enhanceosome, Erythroid Differentiation, ICAT (Isotope Coded Affinity Tag), Quantitative Proteomics, Nuclear Localization, NF-E2, SCL , EKLF, GATA, Post-translational Modifications

Research Activities

Understanding the mechanism by which pluripotential stem cells differentiate to give rise to mature, terminally differentiated cells through a progressive restriction of lineage potential is central to developmental biology and is the long-term goal of the research performed in my lab. My research program is geared toward the identification and the functional characterization of transcription factors and cofactors responsible for regulating gene expression during hematopoietic differentiation.

1- Identify functionally important changes in the interactions between transcription factors occurring on the ?-globin locus during erythroid differentiation

Erythroid differentiation is controlled through changes in transcription factor interactions. Because of its quantitative aspect, the ICAT (Isotope-coded Affinity Tag) technique of proteomics (combined with immunoprecipitation) is the ideal tool to identify functionally important changes in transcription factors' interactions during biological processes. We are currently using a combination of immunoprecipitation and ICAT mass spectrometry technology to identify functionally important changes in transcription factors interactions during erythroid differentiation. Furthermore, we test whether the identified transcription factors and co-factors are recruited to the ?-globin locus during erythroid differentiation using chromatin immunoprecipitation. These experiments are geared toward a complete description of the ?-globin LCR enhanceosome and the changes in interactions occurring within this complex, which leads to the activation of ?-globin transcription during erythroid differentiation.

2- Functional characterization of ?-globin transcriptional co-regulator complexes

Transcriptional co-regulators often possess enzymatic activities (i.e. acetylation, methylation, ubiquitination) and as such are able to modify chromatin structure and/or the function of other non-chromatin associated proteins. Using a combination of in vivo (RNA interference, nucleosome positioning) and in vitro (immunoprecipitations, enzymatic assays) approaches, we are attempting to define the specific role of the identified co-regulator complexes at the levels of chromatin structure, ?-globin transcription and erythroid differentiation.

3- Decipher the role of MafK subnuclear localization in the control of ?-globin transcription during erythroid differentiation.

In differentiated erythrocytes the bZIP factor MafK relocalizes from heterochromatin to euchromatin, coinciding with the movement of the ?-globin locus to the same nuclear compartment. Our hypothesis is that before differentiation, a significant portion of MafK is retained to heterochromatin in order to prevent ?-globin transcription. Conversely, after differentiation the majority of MafK is released into the euchromatic compartment leading to the activation of ?-globin transcription. In order to decipher the molecular mechanism by which a portion of MafK is released from heterochromatin during terminal erythroid differentiation, we are currently purifying MafK-interacting partners from the heterochromatic fraction. These proteins will be identified and compared to euchromatic MafK-interacting proteins using the ICAT proteomics technique.

Major Awards

• Career Award, Canadian Research Chair (Tier 2) in Gene Expression, 2004 - 2009
• Career Development Award, Human Frontier Science Program Organization, 2005 -2007
• Postdoctoral Fellowship, Human Frontier Science Program, 2001-2004
• Postdoctoral Fellowship, European Molecular Biology Organization, 2001

Active Research Funding

• National Cancer Institute of Canada, Operating Grant 2005 – 2008
• Human Frontier Science Program Organization, Career Development Award 2005 – 2007
• Canada Research Chair in Gene Expression, 2004 – 2009

Publications

1. J. Sun, M. Brand , Y. Zenke, S. Tashiro, M. Groudine and K. Igarashi. Heme regulates dynamics of Bach1 and NF-E2-related factors in the Maf transcription factor network. Proceedings of the National Academy of Sciences , 101 (6): 1461-1466, 2004
    
2. M. Brand , J. A. Ranish, N. T. Kummer, J. Hamilton, K. Igarashi, C. Francastel, T. Chi, G. R. Crabtree, R. Aebersold and M. Groudine. Dynamic changes in transcription factors complexes during erythroid differentiation revealed by quantitative proteomics. Nature Structural and Molecular Biology , 11 (1): 73-80, 2004
    
3. N. Cavusoglu , M. Brand , L. Tora and A. Van Dorsselaer. Novel subunits of the TATA Binding Protein Free TAF II -containing transcription complex identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry following one dimensional gel electrophoresis. Proteomics , 3 (2): 217-223, 2003
    
4. S. Hardy, M. Brand , G. Mittler, J. Yanagisawa, S. Kato, M. Meisterernst and L. Tora. TATA-binding protein-Free TAF-containing complex (TFTC) and p300 are both required for efficient transcriptional activation . Journal of Biological Chemistry 277: 32875-32882, 2002, S. Hardy and M. Brand are considered as equal first authors.
    
5. Y. G. Gangloff, J. C. Pointud, S. Thuault, L. Carre, C. Romier, S. Muratoglu, M. Brand , L. Tora, J. L. Couderc and I. Davidson. The TFIID components human TAF(II)140 and Drosophila BIP2 (TAF(II)155) are novel metazoan homologues of yeast TAF(II)47 containing a histone fold and a PHD finger. Molecular and Cellular Biology 21 (15): 5109-51021, 2001
    
6. M. Brand , J. G. Moggs, M. Oulad-Abdelghani, F. Lejeune, F. J. Dilworth, J. Stevenin, G. Almouzni and L. Tora. UV-damaged DNA binding protein in the TFTC complex links DNA damage recognition to nucleosome acetylation. The EMBO Journal 20 (12): 3187-3196, 2001
    
7. L. Tora, M. Brand , E. Wieczorek and D. Metzger. The role of TAF II 30-containing complexes in vertebrate gene regulation. in: Human Frontier Workshop VII on "Transcription Regulation in Eukaryotes" Eds. P. Chambon, R.D. Kornberg, T. Fukasawa and C. Coath. HFSP, Strasbourg, France. pp. 162-170, 1999
    
8. M. Brand , C. Leurent, V. Mallouh, L. Tora and P. Schultz. Three dimensional structures of the TAF II -containing complexes TFIID and TFTC. Science 286: 2151-2153, 1999 , M. Brand and C. Leurent are considered as equal first authors.
    
9. M. Brand , K. Yamamoto, A. Staub and L.Tora. Identification of TFTC subunits suggests a role in nucleosome acetylation and signal transduction. Journal of Biological Chemistry 274 (26): 18285-18289, 1999
    
10. E. Wieczorek, M. Brand , X. Jacq and L. Tora. Function of TAFII-containing complex without TBP in transcription by RNA polymerase II. Nature 393: 187-191, 1998 , E. Wieczorek and M. Brand are considered as equal first authors.