This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (71) Citing Articles via Google Scholar Google Scholar Articles by Price, G. D. Articles by Badger, M. R. Search for Related Content PubMed PubMed Citation Articles by Price, G. D. Articles by Badger, M. R. Agricola Articles by Price, G. D. Articles by Badger, M. R.

Metabolism and Enzymology

Ethoxyzolamide Inhibition of CO₂ Uptake in the Cyanobacterium Synechococcus PCC7942 without Apparent Inhibition of Internal Carbonic Anhydrase Activity ¹

Plant Environmental Biology Group, Research School of Biological Sciences, Australian National University, P.O. Box 475, Canberra City, A.C.T. 2601, Australia

In high inorganic carbon grown (1% CO₂ [volume/volume]) cells of the cyanobacterium Synechococcus PCC7942, the carbonic anhydrase (CA) inhibitor, ethoxyzolamide (EZ), was found to inhibit the rate of CO₂ uptake and to reduce the final internal inorganic carbon (C_i) pool size reached. The relationship between CO₂ fixation rate and internal C_i concentration in high C_i grown cells was little affected by EZ. This suggests that in intact cells internal CA activity was unaffected by EZ. High C_i grown cells readily took up CO₂ but had little or no capacity for HCO₃^– uptake. These cells appear to possess a CO₂ utilizing C_i pump that has a CA-like function associated with the transport step such that HCO₃^– is the species delivered to the cell interior. This CA-like step may be the site of inhibition by EZ. Low C_i grown cells possess both CO₂ uptake and HCO₃^– uptake activities and EZ inhibited both activities to a similar degree, suggesting that a common step in CO₂ and HCO₃^– uptake (such as the C_i pump) may have been affected. The inhibitor had no apparent effect on internal CO₂/HCO₃^– equilibria (internal CA function) in low C_i grown cells.

This article has been cited by other articles:

				F. J. Woodger, D. A. Bryant, and G. D. Price Transcriptional Regulation of the CO2-Concentrating Mechanism in a Euryhaline, Coastal Marine Cyanobacterium, Synechococcus sp. Strain PCC 7002: Role of NdhR/CcmR J. Bacteriol., May 1, 2007; 189(9): 3335 - 3347. [Abstract] [Full Text] [PDF]

				F. J. Woodger, M. R. Badger, and G. D. Price Sensing of Inorganic Carbon Limitation in Synechococcus PCC7942 Is Correlated with the Size of the Internal Inorganic Carbon Pool and Involves Oxygen Plant Physiology, December 1, 2005; 139(4): 1959 - 1969. [Abstract] [Full Text] [PDF]

				G. D. Price, F. J. Woodger, M. R. Badger, S. M. Howitt, and L. Tucker Identification of a SulP-type bicarbonate transporter in marine cyanobacteria PNAS, December 28, 2004; 101(52): 18228 - 18233. [Abstract] [Full Text] [PDF]

				F. J. Woodger, M. R. Badger, and G. D. Price Inorganic Carbon Limitation Induces Transcripts Encoding Components of the CO2-Concentrating Mechanism in Synechococcus sp. PCC7942 through a Redox-Independent Pathway Plant Physiology, December 1, 2003; 133(4): 2069 - 2080. [Abstract] [Full Text]

				H. Ohkawa, G. D. Price, M. R. Badger, and T. Ogawa Mutation of ndh Genes Leads to Inhibition of CO2 Uptake Rather than HCO3- Uptake in Synechocystis sp. Strain PCC 6803 J. Bacteriol., May 1, 2000; 182(9): 2591 - 2596. [Abstract] [Full Text]

				D. Sültemeyer, B. Klughammer, M. R. Badger, and G. Dean Price Fast Induction of High-Affinity HCO3- Transport in Cyanobacteria Plant Physiology, January 1, 1998; 116(1): 183 - 192. [Abstract] [Full Text]