Cytotoxic plant lectins select for mutants which exhibit unique structural changes in surface carbohydrates reflecting specific defects in glycosylation reactions. However, lectins are not highly specific selective agents and, as a result, only the most frequently occurring mutants are obtained from single lectin selections. We have previously shown that the specificity of lectin selections may...

The regulation of intracellular localization of AFX, a human Forkhead transcription factor, was studied. AFX was recovered as a phosphoprotein from transfected COS-7 cells growing in the presence of FBS, and the phosphorylation was eliminated by wortmannin, a potent inhibitor of phosphatidylinositol (PI) 3-kinase. AFX was phosphorylated in vitro by protein kinase B (PKB), a downstream target of...

In addition to suppressing cholesterol synthesis and uptake, oxysterols also activate glycerophospholipid and SM (sphingomyelin) synthesis, possibly to buffer cells from excess sterol accumulation. In the present study, we investigated the effects of oxysterols on the CDP-choline pathway for PtdCho (phosphatidylcholine) synthesis using wild-type and sterol-resistant CHO (Chinese-hamster ovary) ...

Introduction Chinese hamster ovary (CHO) cells [1] are today a very important host for the commercial-scale production of protein pharmaceuticals. Two sub clones of CHO cells, proline-requiring CHO K1 [2] and the dihydrofolate reductase (DHFR) gene-deficient CHO DG44 [3], are the most widely used for both scientific research and industrial applications [4][5,6]. Previously, we constructed a gen...

Iwata M, Silva Enciso J, Greenberg BH. Selective and specific regulation of ectodomain shedding of angiotensin-converting enzyme 2 by tumor necrosis factor -converting enzyme. Am J Physiol Cell Physiol 297: C1318–C1329, 2009. First published September 16, 2009; doi:10.1152/ajpcell.00036.2009.—Angiotensin-converting enzyme 2 (ACE2) is a newly identified regulator of the renin-angiotensin system....

Background: The demand for producing recombinant therapeutic proteins by mammalian cell lines, such as Chinese hamster ovary (CHO) cells, continues to grow. Significant achievements in process optimization including development of cell culture strategies for largescale and cost-effective production have been made. Fetal bovine serum (FBS) is an often essential growth supplement and yet most cos...

Chinese hamster ovarian cells (CHO) cells have been extensively utilized for industrial production of biopharmaceutical products, such as monoclonal antibodies, human growth hormones, cytokines, and blood-products. Recent advances in recombinant DNA technology have resulted in the bioengineering of CHO cells that have robust gene amplification systems and can also be adapted to grow in suspensi...

In Chinese hamster ovary (CHO) fibroblast cells the protein kinase C activating phorbol ester, phorbol myristate acetate (PMA), stimulates an increase in cell surface transferrin receptor (TR) expression by increasing the exocytic rate of the recycling pathway. The human TR expressed in CHO cells is similarly affected by PMA treatment. A mutant human TR in which the major protein kinase C phosp...