University of Pennsylvania: School of Veterinary Medicine

Michael Atchison Ph.D.

Professor of Biochemistry
Director of the VMD-PhD combined degree program

Department of Animal Biology
3800 Spruce Street
School of Veterinary Medicine
University of Pennsylvania
Philadelphia , PA 19104-6010

Qualifications

SUNY at Albany, B.S. (Biology), 1977
New York University School of Medicine, Ph.D. (Cell and Molecular Biology), 1983
Fox Chase Cancer Center, Postdoctoral Fellow (Molecular Biology), 1984-1988

Research Interests

Control of Gene Expression, Development, Immunoglobulins, and Oncogenesis.

Research Summary

The Atchison laboratory is interested in determining the molecular mechanisms responsible for transcriptional regulation and the control of differentiation. To pursue these studies, we explore the functions of a number of transcription factors that regulate immunoglobulin gene expression and that play important roles in lineage differentiation, embryonic development, or oncogenesis. These transcription factors include PU.1, IRF-4, E47, Pax-5, YY1, and Oct4. Each of these proteins is crucial for either proper B cell, myeloid or erythroid development, or for embryonic development. Some may also be involved in the process of somatic hypermutation of rearranged immunoglobulin genes. We pursue our studies by biochemical, molecular biological, genetic, and developmental approaches using a variety of experimental systems including cell lines representing defined stages of B cell development, multipotential tumor lines, transgenic animals, and chimeric mice. In addition to the above mammalian systems, some projects utilize Drosophila systems.

Selected Publications

Bai, Y., Srinivasan, L., Perkins, L., and Atchison, M.L. Protein acetylation regulates both PU.1 transactivation and Igκ 3’ enhancer activity. J. Immunol. 175:5160-5169 (2005).

McDevit, D.C., Perkins, L., Atchison, M.L. , and Nikolajczyk, B.S. The Igκ 3’ enhancer is activated by gradients of chromatin accessibility and protein association. J. Immunol. 174: 2834-2842 (2005).

Srinivasan, L. and Atchison, M.L. YY1 DNA Binding and PcG Recruitment Requires CtBP. Genes Dev. 18: 2596-2601 (2004).

Joo, M., Park, G.Y., Wright, J.G., Blackwell, T.S., Atchison, M. and Christman, J.W. Transcriptional regulation of cyclooxygenase-2 gene in macrophages by PU.1. J. Biol. Chem. 279:6658-6665 (2004).

Atchison, L., Ghias, A., Wilkinson, F., Bonini, N., and Atchison, M.L. Transcription factor YY1 functions as a PcG in vivo. EMBO J. 22:1347-1358 (2003).

Yu, D., Allman, D., Goldschmidt, M.H., Atchison, M.L. , Monroe, J.G., and Thomas-Tikhonenko, A. Oscillation between B-lymphoid and myeloid lineages in Myc-induced hematopoietic tumors following spontaneous silencing/reactivation of the EBF/Pax5 pathway. Blood101:1950-1955(2003).

Lab personnel

Michael Atchison, Ph.D. P.I.
Dr. Atchison tries to work in the lab, and on occasion, actually succeeds. Recent projects include the function of YY1 in developing organisms and the role of PU.1 in somatic hypermutation.

Kyoungsook Park, Ph.D. Visiting Scientist
Dr. Park is studying subcellular localization of CtBP and YY1, and the role of proteins sumoylation in these processes.

Frank Wilkinson, Ph.D. Post-doc
Dr. Wilkinson is studying the role of co-repressor protein CtBP on the ability of YY1 to repress transcription in developing mammalian and fly systems. He is also using transgenic approaches to define specific YY1 regions needed for specific molecular functions.

Lakshmi Srinivasan, Ph.D. Post-doc
Dr. Srinivasan is exploring mechanism of YY1 repression and control of development in mouse and fly systems. She is exploring YY1 recruitment of proteins to DNA by ChIP, and function of YY1 in mammalian development and the immune system

Fang Wei, Ph.D Post-doc
Dr. Wei is exploring the function of transcription factor Oct4 in embryonic stem cells and the function of YY1 and Pax5 in immunoglobulin locus nuclear localization.

Christina Zaprazna, M.S. Graduate Student
Ms. Zaprazna is exploring the mechanism of transcription factor recruitment to DNA of enzymes needed for somatic hypermutation of immunoglobulin V regions.

Suchita Hodawadekar, B.S. Research Specialist
Ms. Hodawadekar is studying developmental alterations in chromatin structure at the mouse Ig locus using chromatin immunoprecipitation assays. She is also is studying the role of Pax5 in controlling B cell vs macrophage development and its role in oncogenesis.

Aisha Ghias, Research Specialist
Ms. Ghias is studying the physical properties of PU.1-Pip-DNA ternary complexes. She is also exploring protein complexes that bind to the immunoglobulin kappa enhancers.

Brandan Youngman, Undergraduate student
Mr. Youngman is studying the mechanisms of PcG protein interactions by GST-pull down assays.

Kathleen O’Roark, Undergraduate student
Ms. O’Roark is studying in vivo interactions of AID with the immunoglobulin loci using cell transfection and ChIP approaches.