Previous work suggests that cell surface heparan sulfate acts as a receptor for the Apicomplexan parasite Toxoplasma gondii. Using Chinese hamster ovary cell mutants defective in heparan sulfate biosynthesis, we show that heparan sulfate is necessary and sufficient for infectivity. Further, we demonstrate that the parasite requires N sulfation of heparan sulfate initiated by N-deacetylase/N-sul...

To further understand the relationships between DNA dam age, DNA repair, and cellular end points such as survival and mutation, the repair capacity of a DNA repair-deficient mutant (strain UV-20) of Chinese hamster ovary cells was character ized in response to DNA cross-linking agents. This mutant, previously shown to be hypersensitive to killing by both ultra violet light and the cross-linking...

The regulation of the activity of transport System L for neutral amino acids has been investigated in Chinese hamster ovary cells. Incubation of the temperature-sensitive leucyl-tRNA synthetase mutant CHO-tsH1 at marginally permissive temperatures results in leucine-limited growth and increased transport of branched chain and aromatic amino acids. This temperature-dependent transport enhancemen...

The bek gene encodes a member of the high-affinity fibroblast growth factor receptor family. The BEK/FGFR-2 receptor is a membrane-spanning tyrosine kinase with the typical features of FGF receptors. We have cloned a murine bek cDNA and expressed it in receptor-negative Chinese hamster ovary cells and in 32D myeloid cells. The BEK receptor expressed in Chinese hamster ovary cells binds acidic F...

We have used the human Lewis blood group fucosyltransferase cDNA and cross-hybridization procedures to isolate a human gene that encodes a distinct fucosyltransferase. Its DNA sequence predicts a type II transmembrane protein whose sequence is identical to 133 of 231 amino acids at corresponding positions within the catalytic domain of the Lewis fucosyltransferase. When expressed by transfectio...

Interaction between ICAM-1 (CD54) and fibrinogen (fg) has been shown to enhance leukocyte adhesion, but its specific role in the process of migration across endothelial cell junctions remains unclear. To overcome the problem of multiple adhesion receptors found on endothelial cells, we have engineered stable Chinese hamster ovary cell lines expressing ICAM-1 (Chinese hamster ovary ICAM-1). The ...

It is widely accepted that functional ATP-binding cassette transporter A1 (ABCA1) is critical for the formation of nascent high density lipoprotein particles. However, the cholesterol pool(s) and the cellular signaling processes utilized by the ABCA1-mediated pathway remain unclear. Sphingomyelin maintains a preferential interaction with cholesterol in membranes, and its catabolites, especially...

In an effort to shed light upon the processes of ant itunior drug-induced cell death, we have carried out a systematic study of the effects of the anti-topoisomerase II agent, etoposide, on Chinese hamster ovary cells. Treatment of Chinese hamster ovary cells for l h with a 2-log cell-killing concentration of etoposide induces a high incidence of DNA single-strand breaks which are rapidly repai...

The findin«that 7r,8f-dihydroxy-9,10f-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene (BPDE-I) is stabilized against hydrolysis by binding to cellular membranes suggested that nucleophilic compounds which would colocalize with BPDE-I in membranes might inhibit the deleterious biological effects of BPDE-I. We have explored the possibility that hydrophobic, sulfhydryl-containing compounds might provide su...

The finding that 7r,8t-dihydroxy-9,10-t-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene (BPDE-I) is stabilized against hydrolysis by binding to cellular membranes suggested that nucleophilic compounds which would colocalize with BPDE-I in membranes might inhibit the deleterious biological effects of BPDE-I. We have explored the possibility that hydrophobic, sulfhydryl-containing compounds might provide s...