Robert Gunsalus Phd


Department of Microbiology, Immunology, and Molecular Genetics

1602 Molecular Science
310-206-8201 | 310-206-5231 (fax)

Research Interests

Research interests of the Gunsalus laboratory address the
physiology and molecular biology of gene expression in the Bacteria and
Archaea. We are studying how cells sense changing environmental conditions, and
adapt their metabolism accordingly. Experimental approaches being used include
whole genome DNA microarrays, classical microbial genetics, biochemistry, and
molecular/structural biology. Model organisms include the methanogenic Archaea
(Methanosarcina acetivorans and Methanosarcina mazei) and enteric bacterial
species including Escherichia coli K-12. The former two microbes produce
methane from the biological precursors, acetate, methanol, methyl-amines, and
in most instances, H2/CO2. We are identifying the gene families involved in use
of the alternative carbon substrates leading to methane formation with the goal
of understanding the regulatory networks and the key regulatory factors. The
Methanosarcina are also versatile in their ability to withstand stress; for
example, they can grow fresh water environments, marine environments, and to
hyper saline environments (ca to 1.2 M NaCl). They do so by synthesis and/or
transport of osmolytes (i.e., N-acetyl-beta-lysine, alpha-glutamate, betaine,
and potassium) whereby the levels of these osmolytes are modulated over a wide
range to adjust osmotic balance. Finally, we are examining the regulatory
mechanisms that allow the common enteric bacterium, E. coli to switch from
aerobic to anaerobic growth. This ability allows comensual as well as
pathogenic strains to adapt and grow successfully inside and outside the human
body by using a variety of genetically programmed strategies.


Recent Papers

  1. Plugge C.M., Henstra A.M., Worm P., Swarts D.C., Paulitsch-Fuchs A.H., Scholten J.C., Lykidis A., Lapidus A.L., Goltsman E., Kim E., McDonald E., Rohlin L., Crable B.R., Gunsalus R.P., Stams A.J., McInerney M.J. “Complete genome sequence of Syntrophobacter fumaroxidans strain (MPOB(T)).” Stand Genomic Sci. 2012 Oct 10;y(1):91-106.
  2. Keseler I.M., Mackie A., Peralta-Gil M., Santos-Zavaleta A., Gama-Castro S., Bonavides-Martinez C., Fulcher C., Huerta A.M., Kothari A., Krummennacker M., Latendresse M., Muñiz-Rascado L., Ong Q., Paley S., Schröder I., Shearer A.G., Subhraveti P., Travers M., Weerasinghe D., Weiss V., Collado-Vides J., Gunsalus R.P., Paulsen I., Karp P.D. “EcoCyc: fusing model organism databases with systems biology.” Nucleic Acids Res. 2013 Jan;41:D605-12.
  3. Sieber J.R., McInerney M.J., Gunsalus R.P. “Genomic insights into syntrophy: the paradigm for anaerobic metabolic cooperation.” Annu Reve Microbiol. 2012;66:429-52.
  4. Arbing M.A., Chan S., Shin A., Phan T., Ahn C.J., Rohlin L., Gunsalus R.P. “Structure of the surface layer of the methanogenic archaean Methanosarcina acetivorans.” Proc Natl Acad Sci USA. 2012 Jul 17;109(29):11812-7.
  5. Rohlin L., Leon D.R., Kim U., Loo J.A., Orgorzalek Loo R.R., Gunsalus R.P. “Identification of the major expressed S-layer and cell surface-layer-related proteins in the model methanogenic archaea: Methanosarcina barkeri Fusaro and Methanosarcina acetivorans C2A.” Archaea. 2012;2012:873589.
  6. Toso D.B., Henstra A.M., Gunsalus R.P., Zhou Z.H., “Structural, mass and elemental analyses of storage granules in methanogenic archaeal cells,” Environ Microbiol. 2011 Sep;13(9):2587-99. Epub 2011 Aug 19.
  7. Keseler I.M., Collado-Vides J., Santos-Zavaleta A., Peralta-Gil M., Gama-Castro S., Muniz-Rascado L., Bonavides-Martinez C., Paley S., Krummenacker M., Altman T., Kaopa P., Spaulding A., Pacheco J., Latendresse M., Fulcher C., Sarker M., Shearer A.G., Mackie A., Paulsen I., Gunsalus R.,P., Karp P.D., “EcoCyc: a comprehensive database of Escherichia coli biology,” Nucleic Acids Res. 2011 Jan;39(Database issue):D593-90. Epub 2010 Nov 21.
  8. Chan S., Giuroiu I., Chernishof I., Sawaya M.R., Chiang J., Gunsalus R.P., Arbing M.A., Perry L.J., “Apo and ligand-bound structures of ModA from the archaeon Methanosarcina acetivorans,” Acta Crystallogr Sect F. Struct Biol Cryst Commun. 2010 Mar 1;66(Pt 3):242-50. Epub 2010 Feb 23.
  9. Rohlin L., Gunsalus R.P., “Carbon-dependent control of electron transfer and central carbon pathway genes for methane biosynthesis in the Archaean, Methanosarcina acetivorans strain C2A,” BMC Microbiol. 2010 Feb 23;10:62.
  10. Lai D., Lluncor B., Schroder I. Gunsalus R.P. Liao J.C., Monbouquette H.G., “Reconstruction of the archaeal isoprenoid ether lipid biosynthesis pathway in Escherichia coli through digeranylgeranylglyceryl phosphate,” Metab Eng. 2009 May;11(3):184-91. Epub 2009 Feb 12.