ISSN:
0739-4462
Keywords:
superoxide dismutase
;
catalase
;
enzyme regulation
;
oxidant
;
anti-oxidant
;
reactive oxygen species
;
sigma factors
;
Chemistry
;
Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
Sophisticated biochemical networks allow organisms such as bacteria and insects to switch from very rapid growth and development in ideal environments to dormancy during severely unfavorable conditions. These switches may be accompanied by abrupt changes in oxidation/reduction involving reactive oxygen species (ROS). ROS have the potential of damaging nucleic acids, proteins, and membranes. In Escherichia coli, certain genetically regulated circuits (regulons) turn on synthesis of anti-oxidant enzymes to protect against distinct ROS excesses (superoxide, hydrogen peroxide, organic or lipid peroxides, etc.). As examples, the soxRS regulon controls synthesis of Mn-superoxide dismutase, oxyR controls catalase HPI, rpoS positively regulates HPII, and fur regulates several oxidative reactions that involve iron uptake. Our studies have focused on the regulatory role of rpoS, known to be a sigma factor (σ38) that combines with RNA polymerase and is a regulator of those gene products needed to protect cells during dormancy. Since insect cells, during both active growth and dormancy, endure severe environments, analogous protective gene products may be induced. Examples are presented of insect anti-oxidant metabolism, including those involved in the aging process. In addition, we searched several DNA and protein sequence data banks to compare resemblances between anti-oxidant gene products of bacteria and insects. © 1995 Wiley-Liss, Inc.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/arch.940290206
Permalink
