Type IV carbonic anhydrase is present in the gills of spiny dogfish (Squalus acanthias)

2007 ◽  
Vol 292 (1) ◽  
pp. R556-R567 ◽  
Author(s):  
K. M. Gilmour ◽  
M. Bayaa ◽  
L. Kenney ◽  
B. McNeill ◽  
S. F. Perry
Keyword(s):  
Amino Acids ◽  
Phylogenetic Analysis ◽  
Epithelial Cells ◽  
Carbonic Anhydrase ◽  
Indirect Evidence ◽  
Gill Tissue ◽  
Squalus Acanthias ◽  
Type Iv ◽  
Pillar Cells ◽  
Branchial Membrane

Physiological and biochemical studies have provided indirect evidence for a membrane-associated carbonic anhydrase (CA) isoform, similar to mammalian type IV CA, in the gills of dogfish ( Squalus acanthias). This CA isoform is linked to the plasma membrane of gill epithelial cells by a glycosylphosphatidylinositol anchor and oriented toward the plasma, such that it can catalyze the dehydration of plasma HCO[Formula: see text] ions. The present study directly tested the hypothesis that CA IV is present in dogfish gills in a location amenable to catalyzing plasma HCO[Formula: see text] dehydration. Homology cloning techniques were used to assemble a 1,127 base pair cDNA that coded for a deduced protein of 306 amino acids. Phylogenetic analysis suggested that this protein was a type IV CA. For purposes of comparison, a second cDNA (1,107 base pairs) was cloned from dogfish blood; it encoded a deduced protein of 260 amino acids that was identified as a cytosolic CA through phylogenetic analysis. Using real-time PCR and in situ hybridization, mRNA expression for the dogfish type IV CA was detected in gill tissue and specifically localized to pillar cells and branchial epithelial cells that flanked the pillar cells. Immunohistochemistry using a polyclonal antibody raised against rainbow trout type IV CA revealed a similar pattern of CA IV immunoreactivity and demonstrated a limited degree of colocalization with Na+-K+-ATPase immunoreactivity. The presence and localization of a type IV CA isoform in the gills of dogfish is consistent with the hypothesis that branchial membrane-bound CA with an extracellular orientation contributes to CO2 excretion in dogfish by catalyzing the dehydration of plasma HCO[Formula: see text] ions.

scholarly journals Phylogenetic analysis and predicted functional effect of protein mutations of E6 and E7 HPV16 strains isolated in Indonesia

2015 ◽  
Vol 24 (4) ◽  
pp. 197-205
Author(s):  
Dwi Wulandari ◽  
Lisnawati Rachmadi ◽  
Tjahjani M. Sudiro
Keyword(s):  
Amino Acids ◽  
Phylogenetic Analysis ◽  
Amino Acid ◽  
Asian American ◽  
Protein Function ◽  
Single Amino Acid ◽  
Hpv16 E6 ◽  
E6 And E7 ◽  
Neutral Mutations

Background: E6 and E7 are oncoproteins of HPV16. Natural amino acid variation in HPV16 E6 can alter its carcinogenic potential. The aim of this study was to analyze phylogenetically E6 and E7 genes and proteins of HPV16 from Indonesia and predict the effects of single amino acid substitution on protein function. This analysis could be used to reduce time, effort, and research cost as initial screening in selection of protein or isolates to be tested in vitro or in vivo.Methods: In this study, E6 and E7 gene sequences were obtained from 12 samples of  Indonesian isolates, which  were compared with HPV16R (prototype) and 6 standard isolates in the category of European (E), Asian (As), Asian-American (AA), African-1 (Af-1), African-2 (Af-2), and North American (NA) branch from Genbank. Bioedit v.7.0.0 was used to analyze the composition and substitution of single amino acids. Phylogenetic analysis of E6 and E7 genes and proteins was performed using Clustal X (1.81) and NJPLOT softwares. Effects of single amino acid substitutions on protein function of E6 and E7 were analysed by SNAP.Results: Java variants and isolate ui66* belonged to European branch, while the others belonged to Asian and African branches. Twelve changes of amino acids were found in E6 and one in E7 proteins. SNAP analysis showed two non neutral mutations, i.e. R10I and C63G in E6 proteins. R10I mutations were found in Af-2 genotype (AF472509) and Indonesian isolates (Af2*), while C63G mutation was found only in Af2*.Conclusion: E6 proteins of HPV16 variants were more variable than E7. SNAP analysis showed that only E6 protein of African-2 branch had functional differences compared to HPV16R.

Carbonic anhydrase activators: Activation of the human isoforms VII (cytosolic) and XIV (transmembrane) with amino acids and amines

2007 ◽  
Vol 17 (15) ◽  
pp. 4107-4112 ◽  
Author(s):  
Daniela Vullo ◽  
Alessio Innocenti ◽  
Isao Nishimori ◽  
Andrea Scozzafava ◽  
Kai Kaila ◽  
...  
Keyword(s):  
Amino Acids ◽  
Carbonic Anhydrase ◽  
Human Isoforms

Characterization of an endothelin ET(B) receptor in the gill of the dogfish shark Squalus acanthias

1999 ◽  
Vol 202 (24) ◽  
pp. 3605-3610 ◽  
Author(s):  
D.H. Evans ◽  
M.P. Gunderson
Keyword(s):  
Blood Vessels ◽  
Gill Tissue ◽  
Squalus Acanthias ◽  
Single Site ◽  
Acid Base Balance ◽  
Ion Regulation ◽  
Base Balance ◽  
Dogfish Shark ◽  
Kinetics Of

Endothelins (ETs) are potent vasoconstrictive peptides that are secreted by the vascular endothelium and other tissues in vertebrates. Previous studies have demonstrated that ETs are expressed in a variety of fish tissues and contract various blood vessels. In order to determine if receptors for ET are expressed in fish gill tissue, we examined the binding kinetics of (125)I-labeled, human ET-1 to membrane fragments isolated from the gill of the dogfish shark, Squalus acanthias. (125)I-ET-1 bound at a single site, with a dissociation constant (K(d)) and binding site number (B(max)) very similar to those described in a variety of mammalian blood vessels. ET-1 and ET-3 competed equally with (125)I-ET-1, suggesting that the receptor was ET(B), which has been shown in mammalian systems to bind to both ligands equally. The ET(B)-specific agonists sarafotoxin S6c, IRL-1620, and BQ-3020 also competed against (125)I-ET-1 at a single site, supporting this hypothesis. We conclude that the shark gill expresses an ET(B) receptor with substantial homology to the mammalian receptor and that ET may play an important role in modulating such vital gill functions as gas exchange, ion regulation, acid-base balance, and excretion of nitrogen.

Transport of amino acids by isolated gills of the mussel Mytilus californianus Conrad

1975 ◽  
Vol 62 (2) ◽  
pp. 313-325
Author(s):  
S. H. Wright ◽  
T. L. Johnson ◽  
J. H. Crowe
Keyword(s):  
Amino Acids ◽  
Significant Role ◽  
Transport Mechanism ◽  
Surrounding Medium ◽  
Gill Tissue ◽  
Mytilus Californianus ◽  
Animal Nutrition ◽  
Neutral Amino Acids ◽  
Kinetics Of

The unidirectional influx of cycloleucine into in vitro preparations of gill tissue of the mussel, Mytilus californianus, was determined. Influx was found to be linear for at least an hour, and the kinetics of cycloleucine influx conformed to Michaelis-Menten type kinetics. The transport mechanism(s) for cycloleucine is relatively specific for the L-enantiomorph of neutral amino acids, and is capable of accumulating cycloleucine to intracellular concentrations much higher than those of the surrounding medium. Evedence is presented that the transport of amino acids by gill tissue plays a significant role in whole animal nutrition.

Collection and analysis of absorbate from proximal straight tubules

1981 ◽  
Vol 241 (6) ◽  
pp. F597-F604 ◽  
Author(s):  
D. W. Barfuss ◽  
J. A. Schafer
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Epithelial Cells ◽  
Water Absorption ◽  
Glucose Concentration ◽  
Volume Absorption ◽  
Steady Rate ◽  
Straight Tubules ◽  
The Difference ◽  
Solute Composition

When isolated segments of rabbit proximal straight tubules were perfused under oil at 37 degrees C, we observed that droplets of absorbate formed on the peritubular surface. Volume absorption under these conditions was the same as with customary aqueous bathing solutions when calculated either from the rate of absorbate formation (0.39 +/- 0.03 nl X min-1 X mm-1) or from the difference in measured perfusion and collection rates (0.37 +/- 0.04 nl X min-1 X mm-1). Absorbate formation continued at a steady rate for at least 2 h but was inhibited by 71% at 28 degrees C. The absorbate was found to have a composition that differed from the perfusate, as would be expected in the presence of preferential absorption of glucose, amino acids, and HCO-3. The Cl- concentration in the absorbate was 11.2 +/- 1.8 mM less than in the perfusate. The glucose concentration in the absorbate was 4.5 mM compared with 0.9 mM in the perfusate. Finally, the nonmetabolizable amino acid cycloleucine, which was added to the perfusate at 0.35 mM, had a concentration of 2.9 mM in the epithelial cells compared with 1.6 mM in the absorbate. These data establish the usefulness of this technique for examining solute and water absorption in the proximal nephron and show that the absorbate can differ considerably in solute composition from the luminal perfusate.

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