The intraerythrocytic human malaria parasite, Plasmodium falciparum, requires a source of hypoxanthine for nucleic acid synthesis and energy metabolism. Adenosine has been implicated as a major source for intraerythrocytic hypoxanthine production via deamination and phosphorolysis, utilizing adenosine deaminase and purine nucleoside phosphorylase, respectively. To study the expression and chara...

Full-length cDNA species encoding two forms of acyl-CoA synthetase from a K-562 human erythroleukaemic cell line were cloned, sequenced and expressed. The first form, named long-chain acyl-CoA synthetase 5 (LACS5), was found to be a novel, unreported, human acyl-CoA synthetase with high similarity to rat brain ACS2 (91% identical). The second form (66% identical with LACS5) was 97% identical wi...

THE PRESENT STUDIES INDICATE THAT ACCUMULATION OF DIGOXIN BY INTACT HUMAN ERYTHROCYTES IS THE RESULT OF TWO PROCESSES: binding of digoxin to the erythrocyte membrane and uptake of digoxin across the membrane into the cell. In contrast, accumulation of ouabain by human erythrocytes is entirely attributable to binding of this glycoside to the plasma membrane. Digoxin binding to the erythrocyte me...

Rosette formation with unsensitized sheep erythrocytes is a characteristic of human thymus dependent lymphocytes. Release of glycopeptides from the sheep erythrocyte by trypsin reduces rosette formation. These tryptic glycopeptides inhibit rosette formation by untrypsinized sheep erythrocytes; this suggests that rosetting is mediated by erythrocyte surface glycopeptides. To investigate the mole...

By BERTRAM A. Lowi’ AND MARJORIE K. WILLIAMS T HE MATURE human erythrocyte, which is incapable of de novo purine nucleotide synthesis, can utilize preformed purines and purine nucleosides for tile formation of purine nucleotides, in vitro.” 2 Studies in this laboratory have demonstrated that adenine is an effective precursor of the ATP of the human erythrocyte and that hypoxanthine, guanine, an...

Inactive nuclei of chick erythrocyte resume RNA synthesis and increase in volume and dry mass in heterokaryons made by virus-induced fusion of human tumor cells (HeLa) with chick erythrocytes. Nuclear growth is due primarily to migration of human macromolecules into the chick nucleus. Human nucleoplasmic antigens were detected in the nucleoplasm and human nucleolar antigens were detected in the...