scholarly journals Role of Trp19 and Tyr200 in catalysis by the γ-class carbonic anhydrase from Methanosarcina thermophila

2013 ◽  
Vol 529 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Sabrina Zimmerman ◽  
John F. Domsic ◽  
Chingkuang Tu ◽  
Arthur H. Robbins ◽  
Robert McKenna ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Methanosarcina Thermophila

Silicon Substitution for Calcium in the Shell of the Fingernail Clam, Musculium Transversum Studied By X-Ray Analysis

1980 ◽  
Vol 38 ◽  
pp. 560-561
Author(s):  
Judith A. Murphy ◽  
Anthony Paparo ◽  
Richard Sparks
Keyword(s):  
Carbonic Anhydrase ◽  
River Water ◽  
Food Chains ◽  
Well Water ◽  
Shell Formation ◽  
X Ray ◽  
Molluscan Shell ◽  
Fingernail Clams

Fingernail clams (Muscu1ium transversum) are dominant bottom-dwelling animals in some waters of the midwest U.S. These organisms are key links in food chains leading from nutrients in water and mud to fish and ducks which are utilized by man. In the mid-1950’s, fingernail clams disappeared from a 100-mile section of the Illinois R., a tributary of the Mississippi R. Some factor(s) in the river and/or sediment currently prevent clams from recolonizing areas where they were formerly abundant. Recently, clams developed shell deformities and died without reproducing. The greatest mortality and highest incidence of shell deformities appeared in test chambers containing the highest proportion of river water to well water. The molluscan shell consists of CaCO3, and the tissue concerned in its secretion is the mantle. The source of the carbonate is probably from metabolic CO2 and the maintenance of ionized Ca concentration in the mantle is controlled by carbonic anhydrase. The Ca is stored in extracellular concentric spherical granules(0.6-5.5μm) which represent a large amount of inertCa in the mantle. The purpose of this investigation was to examine the role of raw river water and well water on shell formation in the fingernail clam.

scholarly journals CHOP-Dependent Stress-Inducible Expression of a Novel Form of Carbonic Anhydrase VI

1999 ◽  
Vol 19 (1) ◽  
pp. 495-504 ◽  
Author(s):  
John Sok ◽  
Xiao-Zhong Wang ◽  
Nikoleta Batchvarova ◽  
Masahiko Kuroda ◽  
Heather Harding ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Target Gene ◽  
Target Genes ◽  
Direct Evidence ◽  
Nuclear Protein ◽  
Intracellular Form ◽  
Carbonic Anhydrase Vi ◽  
Responsive Element

ABSTRACT CHOP (also called GADD153) is a stress-inducible nuclear protein that dimerizes with members of the C/EBP family of transcription factors and was initially identified as an inhibitor of C/EBP binding to classic C/EBP target genes. Subsequent experiments suggested a role for CHOP-C/EBP heterodimers in positively regulating gene expression; however, direct evidence that this is the case has so far not been uncovered. Here we describe the identification of a positively regulated direct CHOP-C/EBP target gene, that encoding murine carbonic anhydrase VI (CA-VI). The stress-inducible form of the gene is expressed from an internal promoter and encodes a novel intracellular form of what is normally a secreted protein. Stress-induced expression of CA-VI is both CHOP and C/EBPβ dependent in that it does not occur in cells deficient in either gene. A CHOP-responsive element was mapped to the inducibleCA-VI promoter, and in vitro footprinting revealed binding of CHOP-C/EBP heterodimers to that site. Rescue of CA-VIexpression in c/ebpβ−/− cells by exogenous C/EBPβ and a shorter, normally inhibitory isoform of the protein known as LIP suggests that the role of the C/EBP partner is limited to targeting the CHOP-containing heterodimer to the response element and points to a preeminent role for CHOP in CA-VI induction during stress.

The role of carbonic anhydrase α-CA4 in the adaptive reactions of photosynthetic apparatus: the study with α-CA4 knockout plants

PROTOPLASMA ◽  
2019 ◽  
Vol 257 (2) ◽  
pp. 489-499 ◽  
Author(s):  
Natalia N. Rudenko ◽  
Tatyana P. Fedorchuk ◽  
Vasily V. Terentyev ◽  
Olga V. Dymova ◽  
Ilya A. Naydov ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Photosynthetic Apparatus ◽  
Adaptive Reactions

Role of Carbonic Anhydrase in Thyroidal Iodide Transport

1984 ◽  
Vol 429 (1 Biology and C) ◽  
pp. 604-606 ◽  
Author(s):  
SIEN YAO CHOW ◽  
JOHN W. KEMP ◽  
DIXON M. WOODBURY
Keyword(s):  
Carbonic Anhydrase ◽  
Iodide Transport

scholarly journals Functional coupling of the downregulated in adenoma Cl−/base exchanger DRA and the apical Na+/H+ exchangers NHE2 and NHE3

2009 ◽  
Vol 296 (2) ◽  
pp. G202-G210 ◽  
Author(s):  
Mark W. Musch ◽  
Donna L. Arvans ◽  
Gary D. Wu ◽  
Eugene B. Chang
Keyword(s):  
Carbonic Anhydrase ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Intestinal Epithelial Cells ◽  
Functional Coupling ◽  
Intestinal Epithelial ◽  
Colon Cells ◽  
Base Exchange ◽  
Synaptotagmin I

Non-nutrient-dependent salt absorption across the brush-border membrane of intestinal epithelial cells is primarily mediated by coupled apical Na+/H+ (aNHE) and anion exchange transport, with the latter suspected of being mediated by DRA (downregulated in adenoma; SLC26A3) that is defective in congenital chloridorrhea. To investigate DRA in greater detail and determine whether DRA and NHE activities can be coupled, we measured 22Na+ and 36Cl− uptake in Caco2BBE colon cells infected with the tet-off-inducible DRA transgene. Under basal conditions, DRA activity was low in normal and infected Caco2BBE cells in the presence of tetracycline, whereas NHE activities could be easily detected. When apical NHE activity was increased by transfection or serum-induced expression of the aNHE isoforms NHE2 and NHE3, increased 36Cl− uptake was observed. Inhibition of DRA activity by niflumic acid was greater than that by DIDS as well as by the NHE inhibitor dimethylamiloride and the carbonic anhydrase inhibitor methazolamide. DRA activity was largely aNHE-dependent, whereas a component of DRA-independent aNHE uptake continued to be observed. Coupled aNHE and DRA activities were inhibited by increased cellular cAMP and calcium and were associated with synaptotagmin I-dependent, clathrin-mediated endocytosis. In summary, these data support the role of DRA in electroneutral NaCl absorption involving functional coupling of Cl−/base exchange and apical NHE.

Methanol Production via Bioelectrocatalytic Reduction of Carbon Dioxide: Role of Carbonic Anhydrase in Improving Electrode Performance

2011 ◽  
Vol 14 (4) ◽  
pp. E9 ◽  
Author(s):  
Paul K. Addo ◽  
Robert L. Arechederra ◽  
Abdul Waheed ◽  
James D. Shoemaker ◽  
William S. Sly ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbonic Anhydrase ◽  
Methanol Production ◽  
Electrode Performance

scholarly journals The Periplasmic α-Carbonic Anhydrase Activity of Helicobacter pylori Is Essential for Acid Acclimation

2005 ◽  
Vol 187 (2) ◽  
pp. 729-738 ◽  
Author(s):  
Elizabeth A. Marcus ◽  
Amiel P. Moshfegh ◽  
George Sachs ◽  
David R. Scott
Keyword(s):  
Helicobacter Pylori ◽  
Membrane Potential ◽  
Carbonic Anhydrase ◽  
Membrane Integrity ◽  
Carbonic Anhydrase Activity ◽  
Knockout Mutant ◽  
Inner Membrane ◽  
Acid Acclimation

ABSTRACT The role of the periplasmic α-carbonic anhydrase (α-CA) (HP1186) in acid acclimation of Helicobacter pylori was investigated. Urease and urea influx through UreI have been shown to be essential for gastric colonization and for acid survival in vitro. Intrabacterial urease generation of NH3 has a major role in regulation of periplasmic pH and inner membrane potential under acidic conditions, allowing adequate bioenergetics for survival and growth. Since α-CA catalyzes the conversion of CO2 to HCO3 −, the role of CO2 in periplasmic buffering was studied using an α-CA deletion mutant and the CA inhibitor acetazolamide. Western analysis confirmed that α-CA was bound to the inner membrane. Immunoblots and PCR confirmed the absence of the enzyme and the gene in the α-CA knockout. In the mutant or in the presence of acetazolamide, there was an ∼3 log10 decrease in acid survival. In acid, absence of α-CA activity decreased membrane integrity, as observed using membrane-permeant and -impermeant fluorescent DNA dyes. The increase in membrane potential and cytoplasmic buffering following urea addition to wild-type organisms in acid was absent in the α-CA knockout mutant and in the presence of acetazolamide, although UreI and urease remained fully functional. At low pH, the elevation of cytoplasmic and periplasmic pH with urea was abolished in the absence of α-CA activity. Hence, buffering of the periplasm to a pH consistent with viability depends not only on NH3 efflux from the cytoplasm but also on the conversion of CO2, produced by urease, to HCO3 − by the periplasmic α-CA.

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