Dawn Clifford Hart, PhD

Associate Professor of Cell & Molecular Biology
322 Henry Hall
hartdaw@gvsu.edu

 

Education:

B.S., (Biology and Psychology as a Natural Science) University of Michigan, Ann Arbor

Ph.D., (Cancer Biology) Wayne State University & Karmanos Cancer Institute, Detroit, Laboratory of George Brush, Ph.D.

NRSA Postdoctoral Fellow, Vanderbilt University & HHMI, Nashville, Laboratory of Kathy Gould, Ph.D.

 

Courses Taught:

CMB250: Introduction to Biotechnology

BIO405: Cell & Molecular Biology

BIO411: Genetics of Development and Cancer

BIO/CMB 426: Nucleic Acids Laboratory

CMB626: Advanced Nucleic Acids Laboratory

CMB697: Colloquium in Biotechnology

 

Research Interests: Cell Division and Protein Phosphorylation

Big Picture Questions: How does a cell know where to divide? How does a cell know when to divide?

Mitosis is the phase of the cell division cycle when chromosomes are pulled to the opposite ends of a cell and the nucleus is evenly divided (Figure 1, nucleus in blue). Concurrently, proteins that are essential for cell division, cell shape and cell motility, namely actin (Figure 1, green) and myosin, undergo dynamic rearrangements within the cell to concentrate at the future site of cell division. Once recruited to the medial region of the cell, actin, myosin and several regulatory proteins coalesce into a ring structure called the “acto-myosin ring”. Physical separation of the mother cell into two identical cells occurs when the acto-myosin ring constricts, a mechanism analogous to muscle contraction. This terminal stage of the cell division cycle is called cytokinesis.

Accurate division of a mother cell into two identical daughter cells is absolutely required to ensure all genes are properly transferred and prevent diseases that may result from cell division defects, such as cancer. Central to this multi-step process is proper assembly of the acto-myosin ring in the center of the cell. In fission yeast, Mid1 is one of the first proteins to concentrate in the mid-region of the cell and functions to specify the future site of cell division. To maintain placement of the acto-myosin ring in the center of the cell, Mid1 acts like a large scaffold or “bridge” that connects the cell wall and cell division machinery. Specifically, Mid1 directly interacts with lipids in the cell membrane and recruits other acto-myosin ring components, such as myosin and actin regulatory proteins. Cells lacking the Mid1 scaffold form “floating” acto-myosin ring structures that appear non-centered and/or tilted. Consequently, the cell divides unevenly and chromosomes are often unequally distributed to the newly generated daughter cells, a situation that can be detrimental to the cell.

Our research employs fission yeast as a model system to study cell division. We utilize genetics, biochemistry, molecular biology and cell imaging to achieve our primary research goal: Elucidate the molecular details of mitosis and cytokinesis. Our current research focuses on understanding acto-myosin ring assembly, maturation and constriction.

 

Undergraduate Research Opportunities: Are you a motivated undergraduate student with a strong interest in research? The Clifford Hart lab has undergraduate fellowships funded by the National Science Foundation RUI Award #1157997. Active participation in a research project related to the goals of the NSF grant will be the main focus of the summer. Students will be expected to participate in research for at least 40 hours per week for 12 weeks, and may not enroll in classes or hold outside employment that will interfere with their research progress. Students are required to continue the project during the following fall and winter semester, either for credit or voluntarily (if credits are not needed towards graduation). The summer stipend is $4000.

The next round of applications will be accepted in January 2014 for fellowships to begin in May 2014. Interested students should e-mail Dr. Clifford Hart the following materials: 1) A current resume or CV and 2) A brief statement (~1 paragraph) that briefly outlines your goals, both for the summer and following graduation from college. What are you hoping to get out of undergraduate research? Where do you see yourself in five years?

 

Publications (*GVSU students underlined):

Almonacid M, Celton-Morizur S, Jakubowski JL*, Dingli F, Loew D, Mayeux A, Chen JS, Gould KL, Clifford DM & Paoletti A. Temporal control of contractile ring assembly by Plo1-dependent regulation of Myosin II recruitment by Mid1/Anillin. Current Biology. 2011, 21(6): 473-479.

Bohnert KA, Chen JS, Clifford DM, Vander Kooi CW, Gould KL. “A Link between Aurora Kinase and Clp1/Cdc14 Regulation Uncovered by the Identification of a Fission Yeast Borealin-like Protein.” Molecular Biology of the Cell. 2009, 20(16):3646-3659.

Clifford DM, Wolfe BA, Roberts-Galbraith RH, McDonald WH, Yates III JR, and Gould KL  “Clp1/Cdc14 phosphatase contributes to the robustness of cytokinesis by association with anillin-related Mid1.”  Journal of Cell Biology. 2008, 181(1):79-88. (Highlighted in VU Reporter, May 2008)

Chen CT, Feoktistova A, Chen JS, Shim YS, Roberts RH, Clifford DM, Gould KL, and McCollum D. “The SIN kinase Sid2 regulates cytoplasmic retention of the S. pombe Cdc14-like phosphatase Clp1.” Current Biology. 2008, 18(20):1594-1599.

Clifford DM, Chen CT, Roberts RH, Feoktistova A, Wolfe BA, Chen JS, McCollum D, and Gould KL. “The role of Cdc14 phosphatases in the control of cell division.” Biochemical Society Transactions. 2008, 36(3):1-3.

Clifford DM, Stark KE, Gardner KE, Hoffmann-Benning S, Brush GS. Mechanistic insight into the Cdc28-related protein kinase Ime2 through analysis of replication protein A phosphorylation. Cell Cycle. 2005, 4(12):1826-1833.

Clifford DM, Marinco SM, Brush GS. The meiosis-specific protein kinase Ime2 directs phosphorylation of replication protein A. Journal of Biological Chemistry. 2004, 279(7):6163-6170.

Brush GS, Clifford DM, Marinco SM, Bartrand AJ. Replication protein A is sequentially phosphorylated during meiosis. Nucleic Acids Research. 2001, 29(23):4808-4817.

 

Presentations with GVSU student researchers (presenter underlined, *GVSU student):
A. International/National Conferences

Marian J. Testori*, Ashley K. DeWitt, Jennifer L. Jakubowski*, David R. Kovar, Dawn M. Clifford Hart. Inhibition of F-actin elongation by the fission yeast Mid1 PH domain. American Society of Cell Biology Annual Conference, New Orleans, LA. December 14-18, 2013.

Marian J. Testori*, Ashley K. DeWitt*, Jennifer Jakubowski*, Brandon Nader*, David Kovar, Dawn Clifford Hart. Elucidation of Mid1 interactions and regulatory mechanisms contributing to stable cortical localization. EMBO Conference on Fission Yeast: pombe 2013 7th International Fission Yeast Meeting. London, UK. June 24-29, 2013.

Ashley K. DeWitt*, Jennifer Phelan*, Brandon Nader*, Kathleen L. Gould, Dawn M. Clifford Hart. Sid2 phospho-regulation of the anillin-related scaffolding protein Mid1 in fission yeast cytokinesis . EMBO Conference on Fission Yeast: pombe 2013 7th International Fission Yeast Meeting. London, UK. June 24-29, 2013.

Marian J. Testori*, Jennifer L. Jakubowski*, David R. Kovar, Dawn M. Clifford Hart. Interaction of the fission yeast Mid1 Pleckstrin Homology domain with the major contractile ring element, F-actin . EMBO Conference on Fission Yeast: pombe 2013 7th International Fission Yeast Meeting. London, UK. June 24-29, 2013.

Ashley DeWitt*, Elizabeth Kranz*, Jennifer Phelan*, Brandon Nader*, Kathleen L. Gould, & Dawn M. Clifford Hart. Phospho-regulation of the anillin-related scaffolding protein Mid1 in fission yeast. American Society of Cell Biology Annual Conference, Denver, CO. December 3-7, 2011.

Justin Hackett*, Jennifer Phelan*, Kathleen L. Gould, & Dawn M. Clifford Hart. Fission yeast cyclin-dependent kinase, Cdc2, regulates the Mid1 scaffolding protein during cytokinesis. American Society of Cell Biology Annual Conference, Denver, CO. December 3-7, 2011.

Jennifer Phelan*, Brandon Nader*, Jennifer L. Jakubowski*, Kathleen L. Gould, & Dawn M. Clifford Hart. Phospho-regulation of the anillin-related scaffolding protein, Mid1. The 6th International Fission Yeast Meeting, Boston, MA. June 25-30, 2011.

Jennifer Phelan*, Kathleen L. Gould, & Dawn M. Clifford Hart. Phospho-regulation of the anillin-related scaffolding protein, Mid1. American Society of Cell Biology Annual Conference, Philadelphia, PA. December 11-15, 2010.

Jennifer Phelan* & Dawn M. Clifford Hart. Phospho-regulation of the anillin-related scaffolding protein, Mid1. Council of Undergraduate Research, Washington D.C. October 2010.

Jennifer L. Jakubowski* & Dawn M. Clifford Hart. Association of the anillin-related protein Mid1 with Actin. American Society of Biochemistry and Molecular Biology Annual Conference, Anaheim, CA. April 2010.

B. Regional and/or Undergraduate Conferences (last two years)

Eric Moore*, Ashley DeWitt & Dawn M. Clifford Hart. Investigating the cellular interaction of Mid1 and protein phosphatase Dis2 in in Schizosaccharomyces pombe cell division. West Michigan Regional Undergraduate Science Research Conference, Van Andel Research Institute, November 16, 2013.

Patrick Schneider*, Ashley K. DeWitt & Dawn M. Clifford Hart. Codifying the proteins involved in the nuclear localization of the Mid1 protein in fission yeast cell division. West Michigan Regional Undergraduate Science Research Conference, Van Andel Research Institute, November 16, 2013.

Sarah VanOeveren*, Marian Testori* & Dawn M. Clifford Hart. Identification of potential cytoskeletal proteins as binding partners of Mid1 in Schizosaccharomyces pombe. West Michigan Regional Undergraduate Science Research Conference, Van Andel Research Institute, November 16, 2013.

Eric Moore* & Dawn M. Clifford Hart. Investigating the cellular interaction of Mid1 and protein phosphatase Dis2 in in Schizosaccharomyces pombe cell division. Midwest Yeast Meeting, Northwestern University, Evanston, IL. September 28-29, 2013.

Jessica Thoe*, Patrick Schneider* & Dawn M. Clifford Hart. Relationships between Mid1 and Polarity Proteins Cka1 and Orb6 in Fission Yeast Cytokinesis. Midwest Yeast Meeting, Northwestern University, Evanston, IL. September 28-29, 2013.

Patrick Schneider*, Ashley K. DeWitt & Dawn M. Clifford Hart. Codifying the proteins involved in the nuclear localization of the Mid1 protein in fission yeast cell division. Midwest Yeast Meeting, Northwestern University, Evanston, IL. September 28-29, 2013.

Sarah VanOeveren*, Marian Testori* & Dawn M. Clifford Hart. Identification of potential cytoskeletal proteins as binding partners of Mid1 in Schizosaccharomyces pombe. Midwest Yeast Meeting, Northwestern University, Evanston, IL. September 28-29, 2013.

Jessica Thoe* & Dawn M. Clifford Hart. Characterizing protein-protein interactions for accurate cell division in fission yeast. Student Scholars Day, GVSU. April 10, 2013.

Jessica Thoe* & Dawn M. Clifford Hart. Characterizing protein-protein interactions for accurate cell division in fission yeast. West Michigan Regional Undergraduate Science Research Conference, Van Andel Research Institute, November 17, 2012.

Marian Testori*, Jennifer L. Jakubowski, Cody Hager and Dawn M. Clifford Hart. The interaction of Mid1 and F-actin in fission yeast. Chicago Cytoskeleton meeting, Northwestern University, March 16, 2012.

Ashley DeWitt*, Elizabeth Kranz*, Jennifer Phelan*, Brandon Nader*, Kathleen L. Gould, & Dawn M. Clifford Hart. Phospho-regulation of the anillin-related scaffolding protein Mid1 in fission yeast. West Michigan Regional Undergraduate Science Research Conference, Van Andel Research Institute, November 12, 2011.

Justin Hackett*, Jennifer Phelan*, Kathleen L. Gould, & Dawn M. Clifford Hart. Fission yeast cyclin-dependent kinase, Cdc2, regulates the Mid1 scaffolding protein during cytokinesis. West Michigan Regional Undergraduate Science Research Conference, Van Andel Research Institute, November 12, 2011.

Elizabeth Kranz*, Brandon Nader*, Kathleen L. Gould,& Dawn M Clifford Hart. Sid2 Phosphorylation Events Regulate Mid1 Membrane Association. West Michigan Regional Undergraduate Science Research Conference, Van Andel Research Institute, November 12, 2011.

Cody Hager*, Jennifer L. Jakubowski* & Dawn M Clifford Hart. Identifying an atypical actin binding domain in the fission yeast Mid1 scaffold. West Michigan Regional Undergraduate Science Research Conference, Van Andel Research Institute, November 12, 2011.

Justin Hackett* & Dawn M. Clifford Hart. Regulation of the scaffolding protein Mid1 in fission yeast cell division. Student Summer Scholar Showcase, GVSU, August 4, 2011.

Cody Hager*, Jennifer L. Jakubowski* & Dawn M Clifford Hart. Identifying an atypical actin binding domain in the fission yeast Mid1 scaffold. Student Scholars Day, GVSU. April 13, 2011.

Brandon Nader* & Dawn M Clifford Hart. Phospho-regulation of Mid1 Assocation with the Medial Cortex. Student Scholars Day, GVSU. April 13, 2011.

Jennifer Phelan* & Dawn M. Clifford Hart. Phospho-regulation of the scaffolding protein, Mid1. Student Scholars Day, GVSU. April 13, 2011.


Other GVSU Presentations:

Clifford Hart, DM. Phospho-regulation of the anillin-related scaffolding protein, Mid1. Chicago Cytoskeleton meeting, Northwestern University, March 16, 2012. (Invited speaker)

Clifford Hart DM, Split down the middle: coordinating cell division in fission yeast. CLAS Faculty Research Colloquia; Allendale, MI. Oct 23, 2009.

Page last modified March 14, 2014