Faculty Profile: Alison DeLong, PHD

Alison DeLong, PHD
Associate Professor of Biology
Molecular Biology, Cell Biology, & Biochemistry
Work: +1 401-863-3888
We are using molecular and genetic approaches to gain insight into the mechanisms that control plant growth and development. Many plant signal transduction pathways involve reversible protein phosphorylation events that regulate key steps in development, as well as responses to the environment. Our goal is to gain insight into the function of protein phosphatase 2A (PP2A), an enzyme that performs important roles in phosphorylation circuits governing growth, morphogenesis and cell fate.

Biography

1982 B.A. with Honors, English Literature
Swarthmore College, Swarthmore, PA

1989 Ph.D., Microbiology and Molecular Genetics
Harvard University, Cambridge MA

1989 - 1992 Postdoctoral Fellow
Biology Department, Yale University
Laboratory of Stephen Dellaporta

1992 - 1994 Postdoctoral Fellow
Department of Molecular Biophysics and Biochemistry, Yale University
Laboratory of Dieter Söll

1994 - 1995 Associate Research Scientist
Department of Molecular Biophysics and Biochemistry, Yale University
Laboratory of Dieter Söll

1996 - 2002 Assistant Professor (Research)
Department of Molecular Biology, Cell Biology and Biochemistry, Brown University

2002 - 2008 Assistant Professor of Biology
Department of Molecular Biology, Cell Biology and Biochemistry, Brown University

2008 - present Associate Professor of Biology
Department of Molecular Biology, Cell Biology and Biochemistry, Brown University

Research Description

We are using molecular and genetic approaches to gain insight into the mechanisms that control plant growth and development. Many plant signal transduction pathways involve reversible protein phosphorylation events that regulate key steps in development, as well as responses to the environment. The activities of protein phosphatases make important contributions to the regulatory circuitry controlling cell biology and development. It is clear that protein phosphatase activities themselves are tightly regulated. Our goal is to gain insight into the function of protein phosphatase 2A (PP2A), an enzyme that performs important roles in phosphorylation cascades governing cell proliferation, morphogenesis and cell fate. Our current research focuses on elucidating the biological functions of PP2A in Arabidopsis thaliana, a 'model species' for which a wealth of molecular genetic tools and techniques have been developed, and for which a completed genome sequence is now available.

My laboratory is using both molecular genetic and proteomic approaches to study PP2A functions in Arabidopsis. Our analysis of one PP2A mutant has already shown that PP2A activity plays a role in regulating plant responses to gravity, a major environmental cue for plant growth. Genetic experiments also suggest a role for PP2A in embryogenesis. Our studies focus on determining the mechanism through which PP2A activity influences these processes, using analytical tools provided by proteomics and biochemistry, as well as molecular biology and genetics.

We are also using a functional genomics approach to isolate new PP2A mutants, to identify additional signal transduction and growth control roles of PP2A. We have systematically analyzed the roles of the three regulatory A subunits of PP2A. Our results suggest that these proteins play overlapping but non-equivalent roles. The RCN1 protein, product of one gene family member, plays a cardinal role in regulation of phosphatase activity, while functions of the other two A subunits are unmasked only when RCN1 is absent. These roles include regulation of embryogenesis, cell expansion and reproductive development.

Grants and Awards

1989-1992 National Science Foundation Postdoctoral Fellowship
1982-1985 National Science Foundation Graduate Fellowship
1982 Phi Beta Kappa

Affiliations

American Society of Plant Biologists

Funded Research

Regulation of Protein Phosphatase 2A Activity in Arabidopsis by the RCN1 Protein
Funded by the National Science Foundation

Selected Publications

  • Tran H.T., M. Nimick, R.G. Uhrig, G. Templeton, N. Morrice, R. Gourlay, A. DeLong, G.B. Moorhead. (2012) Arabidopsis thaliana histone deacetylase 14 (HDA14) is an α-tubulin deacetylase that associates with PP2A and enriches in the microtubule fraction with the putative histone acetyltransferase ELP3. Plant J. 71(2):263-72. doi: 10.1111/j.1365-313X.2012.04984.x. (2012)
  • Skottke, K.R., G.M. Yoon, J.J. Kieber and A. DeLong. (2011) Protein phosphatase 2A controls ethylene biosynthesis by differentially regulating the turnover of ACC synthase isoforms. PLoS Genetics 7(4):e1001370. (2011)
  • Tang, W., M. Yuan, R. Wang, Y. Yang, C. Wang, J.A. Oses-Prieto, T.-W. Kim, H.-W. Zhou, Z. Deng, S.S. Gampala, J.M. Gendron, E.M. Jonassen, C. Lillo, A. DeLong, A.L. Burlingame, Y. Sun and Z.-Y. Wang. (2011) PP2A activates brassinosteroid-responsive gene expression and plant growth by dephosphorylating BZR1. Nature Cell Biology 13:124-31. (2011)
  • Sukumar, P., K.S. Edwards, A. Rahman, A. DeLong and G.K. Muday (2009) PINOID Kinase Regulates Root Gravitropism through Modulation of PIN2-Dependent Basipetal Auxin Transport in Arabidopsis. Plant Physiology 150:722-735. (2009)
  • Blakeslee, J.J., H.-W. Zhou, J.T. Heath, K.R. Skottke, J.A. Rodriguez Barrios, S.Y. Liu and A. DeLong (2008) Specificity of RCN1-mediated protein phosphatase 2A regulation in meristem organization and stress response in roots. Plant Physiology 146:539-53. (2008)
  • Muday, G.K., S. Brady, C. Argueso, J. Deruère, J. Kieber and A. DeLong (2006) RCN1-regulated phosphatase activity and EIN2 modulate hypocotyl gravitropism by a mechanism that does not require ethylene signaling. Plant Physiology 141:1617-29. (2006)
  • DeLong A. Switching the flip: protein phosphatase roles in signaling pathways. Current Opinion in Plant Biology 9:470-477. (2006)
  • Zhou, H.-W., C. Nussbaumer, Y. Chao and A. DeLong (2004) Disparate roles for the regulatory A subunit isoforms in Arabidopsis protein phosphatase 2A. Plant Cell 16:709-722. (2004)
  • DeLong, A., K. Mockaitis and S. Christensen (2002) Protein phosphorylation in the delivery of and response to auxin signals. Plant Mol Biol. 49: 285-303. (2002)
  • Kwak, J.M., J.-H. Moon, Y. Murata, K. Kuchitsu, N. Leonhardt, A. DeLong and J.I. Schroeder (2002) Disruption of a guard cell-expressed protein phosphatase 2A regulatory subunit, RCN1, confers abscisic acid insensitivity in Arabidopsis. Plant Cell 14:2849-2861. (2002)
  • Rashotte, A.M., A. DeLong and G.K. Muday (2001) Genetic and chemical reductions in protein phosphatase activity alter auxin transport, gravity response and lateral root growth. Plant Cell 13:1683-1697. (2001)
  • Muday, G.K. and A. DeLong (2001) Polar auxin transport: Controlling where and how much. Trends in Plant Science 6:535-542. (2001)
  • Deruère, J., K. Jackson, C. Garbers, D. Söll, and A. DeLong (1999) The RCN1-encoded A subunit of protein phosphatase 2A increases phosphatase activity in vivo. Plant Journal 20:389-399. (1999)
  • Lizotte, D., D.D. McManus, H.R. Cohen, and A. DeLong (1999) Functional expression of human and Arabidopsis protein phosphatase 2A in Saccharomyces cerevisiae and isolation of dominant-defective mutants. Gene 234:35-44. (1999)
  • Garbers, C., A. DeLong, J. Deruère, P. Bernasconi and D. Söll (1996) A mutation in Protein Phosphatase 2A Regulatory Subunit A Affects Auxin Transport in Arabidopsis. EMBO J. 15: 2115-2124. (1996)