Marjorie Brand PhD
Tel. (613) 737 7700 ext. 70336
Fax. (613) 739 6294
Senior Scientist, Regenerative Medicine, Ottawa Hospital Research Institute
Associate Professor, University of Ottawa, Department of Medicine, Division of Hematology
Canada Research Chair in the Regulation of Gene Expression
Associate Member of the Ottawa Institute for Systems Biology
|Postdoctoral Fellow||Fred Hutchinson Cancer Research Center (Seattle, WA, USA)|
|PhD||Institut de Génétique et de Biologie Moléculaire et Cellulaire (Strasbourg, France)|
Our main research interest is the regulation of gene expression at the level of transcription and chromatin. We are particularly interested in the transcriptional regulatory network that controls hematopoietic stem cell differentiation towards the erythroid lineage to understand how deregulation of this process can cause leukemia.
Chromatin, Transcription, Epigenetics, Quantitative Mass Spectrometry, ß-globin locus, Leukemia, Hematopoiesis.
Hematopoietic Stem cells have the capacity to differentiate along multiple lineages potentially giving rise to all cells present in the blood. This process is controlled by cell-specific and ubiquitously expressed transcription factors and cofactors. Defects in the transcriptional regulatory network of these cells can lead to leukemia. The major goal of our lab at the Sprott Centre for Stem Cell Research is to decipher the molecular mechanism of Hematopoietic Stem Cell differentiation towards the Erythroid Lineage (i.e. giving rise to red blood cells) and to understand how deregulation of this process can cause Leukemia. Towards this goal, we are using a systems biology approach including quantitative proteomics (isotope tagged methods), genomics (expression microarray, ChIP-sequencing), bioinformatics as well as molecular and cellular biology to understand the regulation of gene expression at the level of transcription, epigenetics and chromatin structure.
Notably, we are employing a recently developed cell culture protocol to induce differentiation of red blood cells ex vivo from Hematopoietic Stem Cells that have been previously extracted from human blood, bone marrow or cord blood. This system provides us with large quantities of cells at various stages of hematopoietic differentiation to perform proteomics experiments.
Our approach involves the isolation of endogenous transcription factors at various stages of hematopoietic differentiation of healthy and/or leukemic cells and identifying their interacting partners by mass spectrometry. Notably, we are using Quantitative Proteomics (ICAT, iTRAQ) methods to pinpoint the dynamics of protein interactions within the transcriptional regulatory network. We expect that understanding the dynamic changes in transcription factors' interactions during cell differentiation will allow us to better control cell fate decisions. For example, we have shown that the bZIP protein MafK regulates ß-globin expression by exchanging its heterodimerization partner from the repressor Bach1 to the activator p45 during erythroid differentiation (Nature Structural and Molecular Biology, 11 (1): 73-80, 2004).
We are also using chromatin immunoprecipitation to study targeting of the identified transcription factors and cofactors to specific genes and/or genome wide as well as the resulting epigenetics modifications. Notably, the ß-globin locus is one of our major model systems. For example, we have shown that during erythroid differentiation, the hematopoietic activator NF-E2 is implicated in recruiting the H3K4 methyltransferase complex MLL2 to the ß-globin locus. Following its recruitment to a distal DNA regulatory region, MLL2 is transferred to the active ß-globin gene over a distance of 40 kb via a "spreading" mechanism (Molecular Cell, 27: 573-584, 2007).
Our most recent studies have focused on the regulation of ß-globin transcription by the histone methyltransferase G9a. We have shown that G9a is involved in maintaining the embryonic ß-globin gene in a repressed state while simultaneously activating the adult ß-globin genes in adult erythroid cells. While the repressive role of G9a relies on methylation of histone H3 at Lys9 and Lys27, its activating function is independent of its methyltransferase activity and involves cooperation with the H3K27 demethylase UTX. Importantly, we have shown that following its recruitment to the ß-globin LCR via interaction with the activator NF-E2, G9a spreads over the entire ß-globin locus in a manner similar to MLL2. (PNAS, 106 (43): 18303-18308, 2009). This reactivation of embryonic ß-globin transcription upon G9a knockdown in adult erythroid cells could play a role in future therapies for patients affected with ß-thalassemia and sickle-cell anemia.
L. Guevel, J.R. Lavoie, C. Perez-Iratxeta, K. Rouger, L. Dubreil, M. Feron, S. Talon, M. Brand* & L. A. Megeney*. Quantitative proteomic analysis of dystrophic dog muscle Journal of Proteome Research, 10 (5): 2465-2478, 2011 * MB and LAM share equal contribution as senior authors
C.G. Palii, R. Pasha & M. Brand. Lentiviral-mediated knockdown during ex vivo erythropoiesis of human hematopoietic stem cells. Journal of Visualized Experiments doi: 10.3791/2813 in press
C.G. Palii*, C. Perez-Iratxeta*, Z. Yao, Y. Cao, F. Dai, J. Davison, H. Atkins, D. Allan, F.J. Dilworth, R. Gentleman, S. Tapscott & M. Brand. Differential genomic targeting of the transcription factor TAL1 in alternate hematopoietic lineages. The EMBO Journal, 30 (3): 494-509, 2011 * co-authors
A.M. Hosey, C-P Chaturvedi & M. Brand. Crosstalk between histone modifications maintains the developmental pattern of gene expression on a tissue-specific locus. Epigenetics, 5 (4): 273-281, 2010
S. Seenundun*, S. Rampalli*, Q. Liu*, A. Aziz, C. Palii, S. Hong, A. Blais, M. Brand, K. Ge & F.J. Dilworth. UTX mediates demethylation of H3K27me3 at muscle-specific genes during myogenesis. The EMBO Journal, 29 (8):1401-1411, 2010 * co-authors
A.M. Hosey & M. Brand. Chromatin-mediated spreading on active genes. Nature Structural and Molecular Biology 16 (1): 11-13, 2009
S. Seenundun*, S. Rampalli*, Q. Liu, S. Hong, C. Palii, A. Blais, M. Brand, K. Ge & F.J. Dilworth. UTX-mediated demethylation of nucleosomes occurs through a two-step mechanism to activate developmentally-regulated gene expression. The EMBO Journal, in press * co-authors
C-P. Chaturvedi*, A.M. Hosey*, C. Palii, C. Perez-Iratxeta, Y. Nakatani, J.A. Ranish, F.J. Dilworth & M. Brand. Dual role for the methyltransferase G9a in the maintenance of ß-globin gene transcription in adult erythroid cells. Proceedings of the National Academy of Sciences, 106 (43): 18303-18308, 2009 * co-authors
M. Brand, S. Rampalli, C-P. Chaturvedi, and F.J. Dilworth. Analysis of epigenetic modifications of chromatin at specific gene loci by native chromatin immunoprecipitation (N-ChIP) of nucleosomes isolated using hydroxyapatite chromatography. Nature Protocols 3 (3): 398-409, 2008
S. Rampalli, L. Li, E. Mak, K. Ge, M. Brand, S.J. Tapscott, and F.J. Dilworth. p38 MAPK signaling pathway regulates recruitment of Ash2L-containing methyltransferase complexes to specific genes during differentiation. Nature Structural and Molecular Biology 14: 1150-1156, 2007
C. Demers, C.P. Chaturvedi, J. A. Ranish, G. Juban, P. Lai, F. Morle, R. Aebersold, F. Dilworth, M. Groudine & M. Brand. Activator-mediated Recruitment of the MLL2 Methyltransferase Complex to the ß-globin Locus. Molecular Cell, 27: 573-584, 2007
J.A Ranish, M. Brand and R. Aebersold. Using stable isotope tagging and MS to characterize protein complexes and to detect changes in their composition. Methods in Molecular Biology, 359:17-35, 2007
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
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
N. Cavusoglu, M. Brand, L. Tora and A. Van Dorsselaer. Novel subunits of the TATA Binding Protein Free TAFII-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
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 *co-authors
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
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
M. Brand*, C. Leurent*, V. Mallouh, L. Tora and P. Schultz. Three dimensional structures of the TAFII-containing complexes TFIID and TFTC. Science 286: 2151-2153, 1999 *co-authors
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
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 *co-authors
Current Lab Members
Chandra-Prakash Chaturvedi, PhD - postdoctoral fellow (CIHR) firstname.lastname@example.org
Fengtao Amanda Dai - PhD student email@example.com
Carmen Palii, PhD - postdoctoral fellow firstname.lastname@example.org
Roya Pasha, PhD - research associate email@example.com
Brinda Somasundaram - MSc student firstname.lastname@example.org
Camilia Thieba - MSc student email@example.com
Jianguo Wu, MSc - research technician firstname.lastname@example.org
Cathy Zhang (MSc student 2007-2010) - PhD student in Dr Min Lin's lab, University of Ottawa
Alison Hosey (Postdoctoral fellow 2008-2010) - Associate, Institute of Strategic Initiatives, CIHR
Zeshawn Awan (MSc student 2005-2007) - Scientific officer, Health Canada
To apply for a postdoctoral position, please send your CV with a list of publication(s) and contact information for three references.
To apply for a graduate student position, please send your CV, university transcripts and a short paragraph describing your career goals. Note that graduate students in the Brand lab should enroll in the CMM program at the University of Ottawa.
Work in our laboratory is funded by:
Canadian Institutes of Health Research
Canadian Research Chairs program
Foundation for Innovation (CFI)
Ontario Ministry of Research and Innovation