Biomaterial Database

Polyphosphoinositide metabolism in aging human erythrocytes. 1985

F B Palmer

Normal human erythrocytes were fractionated in a density gradient. Capacity to metabolize polyphosphoinositides was compared in young (least dense) and old (most dense) cells. Polyphosphoinositide synthesis was assessed by following the incorporation of radioactivity from [gamma-32P]ATP into the 1-(3-sn-phosphatidyl)-D-myo-inositol 4-phosphate (PtdIns4P) and 1-(3-sn-phosphatidyl)-D-myo-inositol 4,5-bisphosphate (PtdIns(4,5)P2) of isolated membranes. There was no significant age-dependent change in the ability to synthesize PtdIns4P and PtdIns(4,5)P2 or in the response of the PtdIns and PtdIns4P kinases to Mg2+. The cytosolic Mg2+-dependent PtdIns(4,5)P2 phosphatase was also unaffected by age. The membrane cation-independent PtdIns4P phosphatase activity declined slightly (12%). Therefore, the capacity to catalyse the interconversion among the three phosphoinositides in the membrane is retained throughout the life of the erythrocyte. The Ca2+-dependent polyphosphoinositide phosphodiesterase activity in the membranes was reduced in old cells (57%) to the same extent as the glutamate-oxaloacetate transaminase activity used as an index of cell age. Thus, irreversible loss of polyphosphoinositide from the membrane by the action of this diesterase (prevented in healthy cells by the active maintenance of a very low intracellular Ca2+ concentration) is not very likely even in senescent cells when Ca2+ homeostasis begins to fail.

UI	MeSH Term	Description	Entries
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D010716	Phosphatidylinositols	Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to the hexahydroxy alcohol, myo-inositol. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid, myo-inositol, and 2 moles of fatty acids.	Inositide Phospholipid,Inositol Phosphoglyceride,Inositol Phosphoglycerides,Inositol Phospholipid,Phosphoinositide,Phosphoinositides,PtdIns,Inositide Phospholipids,Inositol Phospholipids,Phosphatidyl Inositol,Phosphatidylinositol,Inositol, Phosphatidyl,Phosphoglyceride, Inositol,Phosphoglycerides, Inositol,Phospholipid, Inositide,Phospholipid, Inositol,Phospholipids, Inositide,Phospholipids, Inositol
D010749	Phosphoprotein Phosphatases	A group of enzymes removing the SERINE- or THREONINE-bound phosphate groups from a wide range of phosphoproteins, including a number of enzymes which have been phosphorylated under the action of a kinase. (Enzyme Nomenclature, 1992)	Phosphoprotein Phosphatase,Phosphoprotein Phosphohydrolase,Protein Phosphatase,Protein Phosphatases,Casein Phosphatase,Ecto-Phosphoprotein Phosphatase,Nuclear Protein Phosphatase,Phosphohistone Phosphatase,Phosphoprotein Phosphatase-2C,Phosphoseryl-Protein Phosphatase,Protein Phosphatase C,Protein Phosphatase C-I,Protein Phosphatase C-II,Protein Phosphatase H-II,Protein-Serine-Threonine Phosphatase,Protein-Threonine Phosphatase,Serine-Threonine Phosphatase,Threonine Phosphatase,Ecto Phosphoprotein Phosphatase,Phosphatase C, Protein,Phosphatase C-I, Protein,Phosphatase C-II, Protein,Phosphatase H-II, Protein,Phosphatase, Casein,Phosphatase, Ecto-Phosphoprotein,Phosphatase, Nuclear Protein,Phosphatase, Phosphohistone,Phosphatase, Phosphoprotein,Phosphatase, Phosphoseryl-Protein,Phosphatase, Protein,Phosphatase, Protein-Serine-Threonine,Phosphatase, Protein-Threonine,Phosphatase, Serine-Threonine,Phosphatase, Threonine,Phosphatase-2C, Phosphoprotein,Phosphatases, Phosphoprotein,Phosphatases, Protein,Phosphohydrolase, Phosphoprotein,Phosphoprotein Phosphatase 2C,Phosphoseryl Protein Phosphatase,Protein Phosphatase C I,Protein Phosphatase C II,Protein Phosphatase H II,Protein Phosphatase, Nuclear,Protein Serine Threonine Phosphatase,Protein Threonine Phosphatase,Serine Threonine Phosphatase
D004905	Erythrocyte Aging	The senescence of RED BLOOD CELLS. Lacking the organelles that make protein synthesis possible, the mature erythrocyte is incapable of self-repair, reproduction, and carrying out certain functions performed by other cells. This limits the average life span of an erythrocyte to 120 days.	Erythrocyte Survival,Aging, Erythrocyte,Survival, Erythrocyte
D004909	Erythrocyte Indices	ERYTHROCYTE size and HEMOGLOBIN content or concentration, usually derived from ERYTHROCYTE COUNT; BLOOD hemoglobin concentration; and HEMATOCRIT. The indices include the mean corpuscular volume (MCV), the mean corpuscular hemoglobin (MCH), and the mean corpuscular hemoglobin concentration (MCHC).	Erythrocyte Hemoglobin, Mean Cell,Erythrocyte Size Determination,Erythrocyte Volume, Mean Cell,Hemoglobin, Erythrocyte, Mean Cell,Mean Corpuscular Volume,Red Cell Indices,Erythrocyte Diameter,Erythrocyte Index,Erythrocyte Indexes,Erythrocyte Thickness,Mean Cell Hemoglobin Concentration,Mean Cell Volume,Mean Corpuscular Hemoglobin,Mean Corpuscular Hemoglobulin Concentration,Red Cell Distribution Width,Red Cell Index,Red Cell Indexes,Cell Volumes, Mean,Corpuscular Volumes, Mean,Determination, Erythrocyte Size,Determinations, Erythrocyte Size,Diameter, Erythrocyte,Diameters, Erythrocyte,Erythrocyte Diameters,Erythrocyte Size Determinations,Hemoglobin, Mean Corpuscular,Hemoglobins, Mean Corpuscular,Index, Erythrocyte,Index, Red Cell,Indexes, Erythrocyte,Indexes, Red Cell,Indices, Erythrocyte,Indices, Red Cell,Mean Cell Volumes,Mean Corpuscular Hemoglobins,Mean Corpuscular Volumes,Size Determination, Erythrocyte,Size Determinations, Erythrocyte,Thickness, Erythrocyte,Volume, Mean Cell,Volume, Mean Corpuscular,Volumes, Mean Cell,Volumes, Mean Corpuscular
D004910	Erythrocyte Membrane	The semi-permeable outer structure of a red blood cell. It is known as a red cell 'ghost' after HEMOLYSIS.	Erythrocyte Ghost,Red Cell Cytoskeleton,Red Cell Ghost,Erythrocyte Cytoskeleton,Cytoskeleton, Erythrocyte,Cytoskeleton, Red Cell,Erythrocyte Cytoskeletons,Erythrocyte Ghosts,Erythrocyte Membranes,Ghost, Erythrocyte,Ghost, Red Cell,Membrane, Erythrocyte,Red Cell Cytoskeletons,Red Cell Ghosts
D004912	Erythrocytes	Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.	Blood Cells, Red,Blood Corpuscles, Red,Red Blood Cells,Red Blood Corpuscles,Blood Cell, Red,Blood Corpuscle, Red,Erythrocyte,Red Blood Cell,Red Blood Corpuscle
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000251	Adenosine Triphosphatases	A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.	ATPases,Adenosinetriphosphatase,ATPase,ATPase, DNA-Dependent,Adenosine Triphosphatase,DNA-Dependent ATPase,DNA-Dependent Adenosinetriphosphatases,ATPase, DNA Dependent,Adenosinetriphosphatases, DNA-Dependent,DNA Dependent ATPase,DNA Dependent Adenosinetriphosphatases,Triphosphatase, Adenosine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia