3258 TAMU
College Station, TX 77843-3258

Office:
Biological Sciences Building East
Room 314C
979-845-9824

Lab:
Biological Sciences Building East
Room 320
979-845-9821

Fax: 979-845-2891
Email: sgolden@tamu.edu

Susan Stephens Golden joined the Department of Biology at Texas A&M University in 1986. She was promoted to Associate Professor in 1990, to Professor in 1995, and to Distinguished Professor in 2003. Susan graduated salutatorian from Pine Bluff High School (Arkansas) in 1976. She received a B.A. (1978) in Biology from Mississippi University for Women, and a Ph.D. (1983) in Genetics from the University of Missouri. Her postdoctoral work at the University of Chicago was supported by an NIH fellowship.

During her graduate work she developed genetic tools for the cyanobacterium Synechococcus elongatus (PCC 7942), the first cyanobacterium shown to be subject to genetic transformation. This led to work on regulation of light-responsive photosynthesis gene expression in this organism during her postdoctoral research and at TAMU. In the early 1990s she began a collaborative project with C.H. Johnson (Vanderbilt University) and T. Kondo (Nagoya University) that demonstrated circadian rhythms of gene expression in S. elongatus, which is currently the only model organism for a prokaryotic circadian clock. The molecular basis of timekeeping in S. elongatus is now a major focus of her lab. Susan teaches Introductory Biology, Microbial Biotechnology, and a graduate seminar. She is a member of the Center for Research on Biological Clocks and a Fellow of the American Academy of Microbiology.

Diverse eukaryotes, and at least one group of prokaryotes—cyanobacteria—use a circadian (24 h) clock to control physiological events and gene expression. S. elongatus shows a circadian rhythm of bioluminescence when it is transformed with a reporter gene that encodes the luciferase of a bioluminescent marine bacterium or firefly. We are using this reporter system to identify components of circadian system. A group of interacting proteins, KaiA, KaiB, and KaiC are at the heart of the cyanobacterial clock, and kinases help to set the clock and transmit temporal information from it to the genes it regulates. Our goal is to understand the basic mechanism of timekeeping and how the clock becomes synchronized with the environment and controls cellular processes.

Functional Genomics in S. elongatus
We are identifying all of the genes in the S. elongatus genome that contribute to circadian rhythms by creating a mutation in each gene and assaying each mutant for circadian phenotypes. This project uses transposon insertions into cosmids and plasmids that contain pieces of S. elongatus DNA; each clone that carries a transposon insertion can be used for recombination into the S. elongatus genome to produce a gene 'knockout.' A description of the strategy and an update on our progress are available at: http://www.bio.tamu.edu/synecho/.

Metabolic Engineering of Cyanobacteria for the production of Biofuels and other Molecules of Interest
Because cyanobacteria grow photosynthetically using water and CO2 and are easy to manipulate genetically, they are attractive organisms for the production of molecules that have industrial applications. One such application is the production of biofuels as a supplementation of or eventual replacement of petroleum fuels. We using the powerful genetic tools that have been developed for S. elongatus to explore the production of biofuels in cyanobacteria.

Mackey, S.R., J-S. Choi, Y. Kitayama, H. Iwasaki, and S.S. Golden. 2008. Proteins found in a CikA-interaction assay link the circadian clock, metabolism, and cell division in Synechococcus elongatus. J. Bacteriol., in press.

Chen, Y., C.K. Holtman, R.D. Magnuson, P.A. Youderian, S.S. Golden. 2008. The complete sequence and functional analysis of pANL, the large plasmid of the unicellular freshwater cyanobacterium Synechococcus elongatus PCC 7942. Plasmid, in press.

Sharon, I., S. Tzahor, S. Williamson, M. Shmoish, D. Man-Aharonovich, D.B. Rusch, S. Yooseph, Gil Zeidner, S.S. Golden, S.R. Mackey, N. Adir, U. Weingart, D. Horn, J.C. Venter, Y. Mandel-Gutfreund, and O. Béjà. 2007. Viral photosynthetic reaction centre genes and transcripts in the marine environment. ISME J. 1:492-501.

Gao, T., X. Zhang, N.B. Ivelva, S.S. Golden, and A. LiWang. 2007. NMR structure of the pseudo-receiver domain of CikA. Protein Science, 16:465-75.

Mackey, S.R. and S.S. Golden. 2007. Winding up the cyanobacterial circadian clock. Trends Microbiol., 15:381-388. Ivleva, N.B., T. Gao, A. LiWang, and S.S. Golden. 2006. Quinone sensing by the circadian input kinase of the cyanobacterial circadian clock. Proc. Natl. Acad. Sci. USA, 46:17468-17473.

Zhang, X., G. Dong, and S.S. Golden. 2006. The pseudo-receiver domain of CikA regulates the cyanobacterial circadian input pathway. Mol. Microbiol. 60:658-668.

Ditty, J.L., S.R. Canales, B.E. Anderson, S.B. Williams, and S.S. Golden. 2005. Stability of the Synechococcus elongatus PCC 7942 circadian clock under directed anti-phase expression of the kai genes. Microbiology 151:2605-2613.

Ivleva, N.B., M.R. Bramlett, P.A. Lindahl, and S.S. Golden. 2005. LdpA: a component of the circadian clock senses redox state of the cell. EMBO J. 24, 1202-1210.

Vakonakis, I., D.A. Klewer, S.B. Williams, S.S. Golden, and A.C. LiWang. 2004. Structure of the N-terminal domain of the circadian clock-associated histidine kinase SasA. J. Mol. Biol. 42:9-17.

Min, H., Y. Liu, C.H. Johnson, and S.S. Golden. 2004. Phase determination of circadian gene expression in Synechococcus elongatus PCC 7942. J. Biol. Rhythms 19:103-112.

Vakonakis, I., J. Sun, T. Wu, A. Holzenburg, S.S. Golden, and A.C. LiWang. 2004. NMR Structure of the KaiC-interacting C-terminal domain of KaiA, a circadian clock protein: implications for the KaiA-KaiC interaction. Proc. Natl. Acad. Sci. USA 101:1479-1484.

Golden, S.S., and S.R. Canales. 2003. Cyanobacterial circadian clocks - timing is everything. Nature Reviews Microbiol. 1:191-199.

Mutsuda, M., K.P. Michel, X. Zhang, B.L. Montogomery, and S.S. Golden. 2003. Biochemical properties of CikA, an unusual phytochrome-like histidine protein kinase that resets the circadian clock in Synechococcus elongatus PCC 7942. J. Biol. Chem. 278: 19102-19110.

Williams, S.B., I. Vakonakis, S.S. Golden, and A.C. LiWang. 2002. Structure and function from the circadian clock protein KaiA of Synechococcus elongatus: a potential clock input mechanism. Proc. Natl. Acad. Sci. USA 99: 15357-15362.

Nair, U., J.L. Ditty, Y. Xu, H. Min, and S.S. Golden. 2002. Roles for sigma factors in global circadian regulation of the cyanobacterial genome. J. Bacteriol. 184: 3530-3538.

Andersson, C.R., N.F. Tsinoremas, J. Shelton, N.V. Lebedeva, J. Yarrow, H. Min, and S.S. Golden. 2000. Application of bioluminescence to the study of circadian rhythms in cyanobacteria. Methods Enzymol. 305: 527-542.

Schmitz, O., M. Katayama, S.B. Williams, T. Kondo, and S.S. Golden. 2000. CikA, a bacteriophytochrome that resets the cyanobacterial circadian clock. Science 289:765-768.

Iwasaki, H., S.B. Williams, Y. Kitayama, M.. Ishiura, S.S. Golden, and T. Kondo. 2000. A KaiC-interacting sensory histidine kinase, SasA, necessary to sustain robust circadian oscillation in cyanobacteria. Cell 101: 223-233.