The University of Texas Medical School at Houston
Department of Microbiology and Molecular Genetics

Samuel Kaplan, Ph.D.


  • Samuel Kaplan, Ph.D.Professor Emeritus
  • Department of Microbiology &
    Molecular Genetics
  • University of Texas-Houston Medical School
    6431 Fannin Street, MSB 1.200
    Houston, Texas 77030
  • Telephone: (713) 500-5502
    Laboratory Telephone: (713) 500-7436



Ph.D., University of California-San Diego, 1963

Postdoctoral Fellow, MRC laboratories, Cambridge, UK

Research Interests:

Role of oxygen and light in the regulation of gene expression and the nature of
genome complexity in microorganisms

In the laboratory of Professor Samuel Kaplan, the inducible intracytoplasmic membrane system of the bacterium Rhodobacter sphaeroides is employed as a model to study the role(s) of oxygen and light in the regulation of gene expression.

    We are interested in:
  • a molecular genetic analysis of cis and trans-acting genetic elements which respond to light and oxygen. The processing of these signals through electron transport chains, resulting in the control of gene expression.
  • a determination of how the flux of cellular reductant through the various redox pools and terminal oxidases serves to regulate gene expression.
  • the roles of assembly factors and redox intermediates in regulating the assembly of membrane complexes.
  • the use of DNA chip technology to understand how redox-mediated signals serve to regulate global gene expression.

Selected Publications:

  • Seok J-S, Kaplan S, and Oh J-I (2006) Interacting specificity of a histidine kinase and its cognate response regulator: the PrrBA system of Rhodobacter sphaeroides. Microbiol. 152:2479-2490. [abstract]
  • Kim YJ, Ko IJ, Lee JM, Kang HY, Kim YM, Kaplan S, Oh JI (2007) Dominant role of the cbb3 oxidase in regulation of photosynthesis gene expression through the PrrBA system in Rhodobacter sphaeroides 2.4.1. J. Bacteriol. 189(15):5617-5625. [abstract]
  • Mackenzie C, Eraso JM, Choudhary M, Roh JH, Zeng X, Bruscella P, Puskás Á, Kaplan S (2007) Postgenonic adventures with Rhodobacter sphaeroides Annu. Rev. Microbiol. 61:283-307. [abstract]
  • Pan D, Hu D, Liu R, Zeng X, Kaplan S, Lu HP (2007) Fluctuating two-state light harvesting in a photosynthetic membrane. J. Phys. Chem. 111:8948-8956. [abstract]
  • Hemp J, Han H, Roh JH, Kaplan S, Martinez TJ, Gennis RB (2007) Comparitive genomics and site-directed mutagenesis support the existence of only one input channel for protons in the C-family (cbb3 oxidase) of heme-copper oxygen reductases. Biochem. 46(35):9963-9972. [abstract]
  • Moskvin OV, Kaplan S, Gilles-Gonzalez M-A, Gomelsky M (2007) Novel heme-based oxygen sensor with a revealing evolutionary history J. Biol. Chem. 282(39):28740-28748. [abstract]
  • Zeng X, Roh JH, Callister SJ, Tavano CL, Donohue TJ, Lipton MS, Kaplan S (2007) Proteomic characterization of the Rhodobacter sphaeroides 2.4.1. photosynthetic membrane: identification of new proteins. J. Bacteriol. 189(20):7464-7474. [abstract]
  • Arai H, Roh JH, Kaplan S (2007) Transcriptome dynamics during the transition from anaerobic photosynthesis to aerobic respiration in Rhodobacter sphaeroides 2.4.1. J. Bacteriol. In press. [abstract]

[Search PubMed for more papers by Samuel Kaplan]