• Conspectus
• Lékařské vědy. Lékařství
• NML Fields
• hematologie a transfuzní lékařství
• fyziologie

• MeSH
• Biochemistry MeSH
• Enzymes MeSH
• Hemoglobins MeSH
• Molecular Biology MeSH
• Proteins MeSH

• Conspectus
• Biochemie. Molekulární biologie. Biofyzika
• NML Fields
• biochemie

During vertebrate evolution, structural changes in red blood cells (RBC) and hemoglobin (Hb), have probably resulted in the importance of blood carbon dioxide transport. The chloride/bicarbonate exchange across the RBC membrane, which is an integral part of the blood CO2 transport process in vertebrates, has been examined on two different species of teleost fish, Euthynnus alletteratus and Thunnus thynnus, at several oxygenation states of erythrocyte HOS (high-oxygenation state, about 90 % of saturation) and LOS (low-oxygenation state, about 15 % of saturation). The results were compared with those observed in human RBC under the same experimental conditions and with the chicken (Gallus gallus) erythrocytes, which have particular modifications at the N-terminus of the band 3 protein (B3). In fish the kinetic measurements have shown a different anion transport in several oxygenation states of erythrocytes, indicating that also at lower levels of vertebrate evolution there exists a modulation of the anionic flow affected by oxygen. The functional correlation of anion transport to changes of parts of the hemoglobin sequence responsible for alterations in the interactions with the cytoplasmic domain of band 3 protein (cdb3) allowed us to suggest a hypothesis about fish physiology. The highest values of kinetic measurements observed in fish have been attributed to the metabolic need of the RBC in response to the removal of CO2 that in teleosts is also of endogenous origin.

• MeSH
• Adult MeSH
• Species Specificity MeSH
• Anion Exchange Protein 1, Erythrocyte physiology   MeSH
• Erythrocytes metabolism   MeSH
• Hemoglobins chemistry   metabolism   MeSH
• Ion Transport physiology   MeSH
• Chickens MeSH
• Oxygen blood   MeSH
• Middle Aged MeSH
• Humans MeSH
• Carbon Dioxide blood   MeSH
• Fish Proteins physiology   MeSH
• Tuna metabolism   MeSH
• Animals MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Animals MeSH

• MeSH
• Bacteriology MeSH
• Hematology MeSH
• Chemistry, Clinical MeSH
• Clinical Laboratory Techniques MeSH
• Parasitology MeSH
• Serology MeSH
• Toxicology MeSH
• Tropical Medicine MeSH
• Publication type
• Monograph MeSH
• Textbook MeSH

• Conspectus
• Patologie. Klinická medicína
• Učební osnovy. Vyučovací předměty. Učebnice
• NML Fields
• diagnostika
• chemie, klinická chemie

• Keywords
• Hematologie,
• MeSH
• Hematology MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• hematologie a transfuzní lékařství
• alergologie a imunologie
• vnitřní lékařství

• Keywords
• Hematologie, Učebnice,
• MeSH
• Hematology MeSH
• Publication type
• Textbook MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• hematologie a transfuzní lékařství
• vnitřní lékařství

• MeSH
• Hematology MeSH
• Hematologic Diseases diagnosis   therapy   MeSH
• Publication type
• Monograph MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• hematologie a transfuzní lékařství

• MeSH
• Chronic Disease MeSH
• Persons with Disabilities MeSH
• Publication type
• Monograph MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• zdravotně postižení

• MeSH
• Hematology MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• hematologie a transfuzní lékařství
• NML Publication type
• kolektivní monografie

Blood-feeding parasites are inadvertently exposed to high doses of potentially cytotoxic haem liberated upon host blood digestion. Detoxification of free haem is a special challenge for ticks, which digest haemoglobin intracellularly. Ticks lack a haem catabolic mechanism, mediated by haem oxygenase, and need to dispose of vast majority of acquired haem via its accumulation in haemosomes. The knowledge of individual molecules involved in the maintenance of haem homeostasis in ticks is still rather limited. RNA-seq analyses of the Ixodes ricinus midguts from blood- and serum-fed females identified an abundant transcript of glutathione S-transferase (gst) to be substantially up-regulated in the presence of red blood cells in the diet. Here, we have determined the full sequence of this encoding gene, ir-gst1, and found that it is homologous to the delta-/epsilon-class of GSTs. Phylogenetic analyses across related chelicerates revealed that only one clear IrGST1 orthologue could be found in each available transcriptome from hard and soft ticks. These orthologues create a well-supported clade clearly separated from other ticks' or mites' delta-/epsilon-class GSTs and most likely evolved as an adaptation to tick blood-feeding life style. We have confirmed that IrGST1 expression is induced by dietary haem(oglobin), and not by iron or other components of host blood. Kinetic properties of recombinant IrGST1 were evaluated by model and natural GST substrates. The enzyme was also shown to bind haemin in vitro as evidenced by inhibition assay, VIS spectrophotometry, gel filtration, and affinity chromatography. In the native state, IrGST1 forms a dimer which further polymerises upon binding of excessive amount of haemin molecules. Due to susceptibility of ticks to haem as a signalling molecule, we speculate that the expression of IrGST1 in tick midgut functions as intracellular buffer of labile haem pool to ameliorate its cytotoxic effects upon haemoglobin intracellular hydrolysis.

• MeSH
• Phylogeny * MeSH
• Glutathione Transferase * biosynthesis   chemistry   genetics   MeSH
• Hemoglobins chemistry   metabolism   MeSH
• Ixodes * enzymology   genetics   MeSH
• Arthropod Proteins * biosynthesis   chemistry   genetics   MeSH
• Gene Expression Regulation, Enzymologic physiology   MeSH
• Substrate Specificity MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH