Anion Exchange Protein 1, Erythrocyte
A major integral transmembrane protein of the ERYTHROCYTE MEMBRANE. It is the anion exchanger responsible for electroneutral transporting in CHLORIDE IONS in exchange of BICARBONATE IONS allowing CO2 uptake and transport from tissues to lungs by the red blood cells. Genetic mutations that result in a loss of the protein function have been associated with type 4 HEREDITARY SPHEROCYTOSIS.
SLC4A Proteins
Bicarbonate transporters that move BICARBONATE IONS in exchange of CHLORIDE IONS or SODIUM IONS across membranes. They regulate acid-base HOMEOSTASIS, cell volume and intracellular pH. Members include CHLORIDE-BICARBONATE ANTIPORTERS (SLC4A1, 2, 3, and 9); SODIUM-COUPLED BICARBONATE TRANSPORTERS (SLC4A4 and 5, 7, 8 and 10); and a sodium borate cotransporter (SLC4A11 protein).
Anion Transport Proteins
4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid
A non-penetrating amino reagent (commonly called SITS) which acts as an inhibitor of anion transport in erythrocytes and other cells.
Erythrocytes
Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.
Antiporters
Erythrocyte Membrane
The semi-permeable outer structure of a red blood cell. It is known as a red cell 'ghost' after HEMOLYSIS.
Anions
Anion Exchange Resins
High-molecular-weight insoluble polymers that contain functional cationic groups capable of undergoing exchange reactions with anions.
Guanine Nucleotide Exchange Factors
Protein factors that promote the exchange of GTP for GDP bound to GTP-BINDING PROTEINS.
rap1 GTP-Binding Proteins
A genetically related subfamily of RAP GTP-BINDING PROTEINS that share homology with RAS PROTEINS. They bind to Ras effectors but do not activate them, therefore they may antagonize the effects of RAS PROTEINS. This enzyme was formerly listed as EC 3.6.1.47.
Chromatography, Ion Exchange
Separation technique in which the stationary phase consists of ion exchange resins. The resins contain loosely held small ions that easily exchange places with other small ions of like charge present in solutions washed over the resins.
Cyclic AMP
rab3 GTP-Binding Proteins
A genetically related subfamily of RAB GTP-BINDING PROTEINS involved in calcium-dependent EXOCYTOSIS. This enzyme was formerly listed as EC 3.6.1.47.
rap GTP-Binding Proteins
A family of MONOMERIC GTP-BINDING PROTEINS that are related to RAS PROTEINS.This enzyme was formerly listed as EC 3.6.1.47.
Erythrocyte Aging
Cyclic AMP-Dependent Protein Kinases
A group of enzymes that are dependent on CYCLIC AMP and catalyze the phosphorylation of SERINE or THREONINE residues on proteins. Included under this category are two cyclic-AMP-dependent protein kinase subtypes, each of which is defined by its subunit composition.
4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid
Chloride-Bicarbonate Antiporters
Electroneutral chloride bicarbonate exchangers that allow the exchange of BICARBONATE IONS exchange for CHLORIDE IONS across the cellular membrane. The action of specific antiporters in this class serve important functions such as allowing the efficient exchange of bicarbonate across red blood cell membranes as they passage through capillaries and the reabsorption of bicarbonate ions by the kidney.
Hydrogen-Ion Concentration
rho-Specific Guanine Nucleotide Dissociation Inhibitors
A subcategory of guanine nucleotide dissociation inhibitors that are specific for RHO GTP-BINDING PROTEINS.
Ion Exchange
Reversible chemical reaction between a solid, often one of the ION EXCHANGE RESINS, and a fluid whereby ions may be exchanged from one substance to another. This technique is used in water purification, in research, and in industry.
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Carrier Proteins
Transport proteins that carry specific substances in the blood or across cell membranes.
Bicarbonates
Guanine Nucleotide Dissociation Inhibitors
Protein factors that inhibit the dissociation of GDP from GTP-BINDING PROTEINS.
Amino Acid Sequence
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Guanosine Diphosphate
ras Guanine Nucleotide Exchange Factors
Biological Transport
Erythrocyte Deformability
Ability of ERYTHROCYTES to change shape as they pass through narrow spaces, such as the microvasculature.
Electrophoresis, Polyacrylamide Gel
Ion Exchange Resins
High molecular weight, insoluble polymers which contain functional groups that are capable of undergoing exchange reactions (ION EXCHANGE) with either cations or anions.
Phosphatidylcholines
Exoribonucleases
Membrane Proteins
GTP-Binding Proteins
Regulatory proteins that act as molecular switches. They control a wide range of biological processes including: receptor signaling, intracellular signal transduction pathways, and protein synthesis. Their activity is regulated by factors that control their ability to bind to and hydrolyze GTP to GDP. EC 3.6.1.-.
Son of Sevenless Proteins
A class of RAS GUANINE NUCLEOTIDE EXCHANGE FACTORS that are genetically related to the Son of Sevenless gene from DROSOPHILA. Sevenless refers to genetic mutations in DROSOPHILA that cause loss of the R7 photoreceptor which is required to see UV light.
Cell Membrane
Cattle
Hemolysis
The destruction of ERYTHROCYTES by many different causal agents such as antibodies, bacteria, chemicals, temperature, and changes in tonicity.
Chromatography, High Pressure Liquid
Phospholipid Transfer Proteins
A ubiquitous family of proteins that transport PHOSPHOLIPIDS such as PHOSPHATIDYLINOSITOL and PHOSPHATIDYLCHOLINE between membranes. They play an important role in phospholipid metabolism during vesicular transport and SIGNAL TRANSDUCTION.
Protein Binding
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
Bromides
Chromatography, Gel
Oxalates
Signal Transduction
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
Erythrocyte Aggregation
The formation of clumps of RED BLOOD CELLS under low or non-flow conditions, resulting from the attraction forces between the red blood cells. The cells adhere to each other in rouleaux aggregates. Slight mechanical force, such as occurs in the circulation, is enough to disperse these aggregates. Stronger or weaker than normal aggregation may result from a variety of effects in the ERYTHROCYTE MEMBRANE or in BLOOD PLASMA. The degree of aggregation is affected by ERYTHROCYTE DEFORMABILITY, erythrocyte membrane sialylation, masking of negative surface charge by plasma proteins, etc. BLOOD VISCOSITY and the ERYTHROCYTE SEDIMENTATION RATE are affected by the amount of erythrocyte aggregation and are parameters used to measure the aggregation.
Proteins
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
Sodium-Calcium Exchanger
An electrogenic ion exchange protein that maintains a steady level of calcium by removing an amount of calcium equal to that which enters the cells. It is widely distributed in most excitable membranes, including the brain and heart.
Cells, Cultured
Enzyme Activation
Substrate Specificity
Isoelectric Point
The pH in solutions of proteins and related compounds at which the dipolar ions are at a maximum.
Epichlorohydrin
Colforsin
Potent activator of the adenylate cyclase system and the biosynthesis of cyclic AMP. From the plant COLEUS FORSKOHLII. Has antihypertensive, positive inotropic, platelet aggregation inhibitory, and smooth muscle relaxant activities; also lowers intraocular pressure and promotes release of hormones from the pituitary gland.
Sodium
Liposomes
Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.
Calcium
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Base Sequence
Phospholipids
Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.
Binding Sites
Biological Transport, Active
8-Bromo Cyclic Adenosine Monophosphate
A long-acting derivative of cyclic AMP. It is an activator of cyclic AMP-dependent protein kinase, but resistant to degradation by cyclic AMP phosphodiesterase.
Deuterium Exchange Measurement
Erythrocyte Volume
Volume of circulating ERYTHROCYTES . It is usually measured by RADIOISOTOPE DILUTION TECHNIQUE.
Organic Anion Transporters
Proteins involved in the transport of organic anions. They play an important role in the elimination of a variety of endogenous substances, xenobiotics and their metabolites from the body.
Models, Biological
Benzylammonium Compounds
Glycophorin
The major sialoglycoprotein of the human erythrocyte membrane. It consists of at least two sialoglycopeptides and is composed of 60% carbohydrate including sialic acid and 40% protein. It is involved in a number of different biological activities including the binding of MN blood groups, influenza viruses, kidney bean phytohemagglutinin, and wheat germ agglutinin.
Pulmonary Gas Exchange
DNA, Single-Stranded
Cloning, Molecular
Cell Membrane Permeability
Exchange Transfusion, Whole Blood
Repetitive withdrawal of small amounts of blood and replacement with donor blood until a large proportion of the blood volume has been exchanged. Used in treatment of fetal erythroblastosis, hepatic coma, sickle cell anemia, disseminated intravascular coagulation, septicemia, burns, thrombotic thrombopenic purpura, and fulminant malaria.
Guanosine Triphosphate
Rabbits
Proto-Oncogene Proteins p21(ras)
Cellular proteins encoded by the H-ras, K-ras and N-ras genes. The proteins have GTPase activity and are involved in signal transduction as monomeric GTP-binding proteins. Elevated levels of p21 c-ras have been associated with neoplasia. This enzyme was formerly listed as EC 3.6.1.47.
Chromatography
Techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. A mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. Usage is both analytical for small amounts and preparative for bulk amounts.
Plasmodium falciparum
Sister Chromatid Exchange
An exchange of segments between the sister chromatids of a chromosome, either between the sister chromatids of a meiotic tetrad or between the sister chromatids of a duplicated somatic chromosome. Its frequency is increased by ultraviolet and ionizing radiation and other mutagenic agents and is particularly high in BLOOM SYNDROME.
Sodium-Hydrogen Antiporter
Temperature
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
Osmotic Fragility
RED BLOOD CELL sensitivity to change in OSMOTIC PRESSURE. When exposed to a hypotonic concentration of sodium in a solution, red cells take in more water, swell until the capacity of the cell membrane is exceeded, and burst.
Blood Proteins
Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.
Mutation
Spectrin
A high molecular weight (220-250 kDa) water-soluble protein which can be extracted from erythrocyte ghosts in low ionic strength buffers. The protein contains no lipids or carbohydrates, is the predominant species of peripheral erythrocyte membrane proteins, and exists as a fibrous coating on the inner, cytoplasmic surface of the membrane.
Rad51 Recombinase
Hemagglutination
The aggregation of ERYTHROCYTES by AGGLUTININS, including antibodies, lectins, and viral proteins (HEMAGGLUTINATION, VIRAL).
Phosphorylation
Resins, Synthetic
Polymers of high molecular weight which at some stage are capable of being molded and then harden to form useful components.
p-Aminohippuric Acid
The glycine amide of 4-aminobenzoic acid. Its sodium salt is used as a diagnostic aid to measure effective renal plasma flow (ERPF) and excretory capacity.
Potassium
An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
Recombination, Genetic
Guanosine 5'-O-(3-Thiotriphosphate)
Guanosine 5'-(trihydrogen diphosphate), monoanhydride with phosphorothioic acid. A stable GTP analog which enjoys a variety of physiological actions such as stimulation of guanine nucleotide-binding proteins, phosphoinositide hydrolysis, cyclic AMP accumulation, and activation of specific proto-oncogenes.
Organic Anion Transporters, Sodium-Independent
A subclass of ORGANIC ANION TRANSPORTERS that do not rely directly or indirectly upon sodium ion gradients for the transport of organic ions.
Chromatography, Affinity
Magnetic Resonance Spectroscopy
Transfection
Amiloride
A pyrazine compound inhibiting SODIUM reabsorption through SODIUM CHANNELS in renal EPITHELIAL CELLS. This inhibition creates a negative potential in the luminal membranes of principal cells, located in the distal convoluted tubule and collecting duct. Negative potential reduces secretion of potassium and hydrogen ions. Amiloride is used in conjunction with DIURETICS to spare POTASSIUM loss. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p705)
Saccharomyces cerevisiae Proteins
Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.
Protein Processing, Post-Translational
Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.
Ion Transport
Ethoxzolamide
Structure-Activity Relationship
Recombinant Fusion Proteins
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
Voltage-Dependent Anion Channels
A family of voltage-gated eukaryotic porins that form aqueous channels. They play an essential role in mitochondrial CELL MEMBRANE PERMEABILITY, are often regulated by BCL-2 PROTO-ONCOGENE PROTEINS, and have been implicated in APOPTOSIS.
Carbohydrate Sequence
The sequence of carbohydrates within POLYSACCHARIDES; GLYCOPROTEINS; and GLYCOLIPIDS.
Mass Spectrometry
Adenosine Triphosphate
An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.
Saccharomyces cerevisiae
Carbohydrates
The largest class of organic compounds, including STARCH; GLYCOGEN; CELLULOSE; POLYSACCHARIDES; and simple MONOSACCHARIDES. Carbohydrates are composed of carbon, hydrogen, and oxygen in a ratio of Cn(H2O)n.