we searched for novel chinese hamster ovary (cho) cell mutants defective in peroxisome biogenesis by an improved method using peroxisome targeting sequence (pts) of pex3p (amino acid residues 1–40)-fused enhanced green fluorescent protein (egfp). from mutagenized tkaeg3(1–40) cells, the wild-type cho-k1 stably expressing rat pex2p and of rat pex3p(1–40)-egfp, numerous cell colonies resistant to...

We searched for novel Chinese hamster ovary (CHO) cell mutants defective in peroxisome biogenesis by an improved method using peroxisome targeting sequence (PTS) of Pex3p (amino acid residues 1–40)-fused enhanced green fluorescent protein (EGFP). From mutagenized TKaEG3(1–40) cells, the wild-type CHO-K1 stably expressing rat Pex2p and of rat Pex3p(1–40)-EGFP, numerous cell colonies resistant to...

Inefficient secretion of the human coagulation factor (hFVIII) in mammalian expression systems is one ofthe main causes of the hFVIII low expression level, attributed to its interaction with a chaperone known asBiP/GRP78. In order to improve secretion efficiency of the hFVIII, based on the higher secretion level of theporcine FVIII and analysis of the hFVIII A110 region, that ...

We have examined the role of cell surface glycosaminoglycans in cell division: adhesion and proliferation of Chinese hamster ovary (CHO) cells. We used both wild-type (CHO-K1) cells and a mutant (CHO-745) which is deficient in the synthesis of proteoglycans due to lack of activity of xylosyl transferase. Using different amounts of wild-type and mutant cells, little adhesion was observed in the ...

Phosphatidylserine (PtdSer) synthesis in Chinese hamster ovary (CHO) cells occurs through the exchange of L-serine with the base moiety of phosphatidylcholine or phosphatidylethanolamine. The synthesis is depressed on the addition of PtdSer to the culture medium. A CHO cell mutant named mutant 29, whose PtdSer biosynthesis is highly resistant to this depression by exogenous PtdSer, has been iso...

Chinese hamster ovary (CHO) cells are considered as the most commonly used host for industrial manufacturing of therapeutic proteins. The aim of this study was to evaluate the minimum inhibitory concentration (MIC) of hygromycin B in both CHO-DG44 and CHO-S cells since hygromycin B resistance cassette can be used for future selection of gene expression in CHO cells. The minimum inhibitory conce...

We have used the technique of somatic cell hybridization to study the regulation of the neutral amino acid transport system L in Chinese hamster ovary (CHO) cells. The cell line CHO-ts025C1 has a temperature-sensitive mutation in leucyl-tRNA synthetase. At the nonpermissive temperature of 39 degrees C, CHO-ts025C1 cells are unable to charge leucyl-tRNA and behave as though starved for leucine b...

To investigate the role of the cAMP-dependent protein kinase (PKA) in the desensitization and down-regulation of the D(1) dopamine receptor, we stably expressed the rat cDNA for this receptor in mutant Chinese hamster ovary (CHO) cell lines deficient in PKA activity. The 10260 mutant CHO cell line has been characterized as expressing less than 10% of type I and type II PKA activities relative t...

The CHO-UV-1 mutant, a Chinese hamster ovary cell with defective postreplication recovery of DNA, is 2- to 4-fold more sensitive than its wild-type counterpart (CHO-77256) to the lethal effects of ethylating agents and UV radiation; it is also hypersensitive (10- to 20-fold) to some DNA-methylating and -cross-linking agents. We studied the CHO-UV-1 mutant further to define its phenotype in term...

proteinase 3(pr3) is a human polymorphonuclear leukocyte serine proteinase and is the main target antigen for antineutrophil cytoplasmic antibodies (anca) found in wegener's granulomatosis (wg). we developed a stable expression system for conformationally intact recombinant pr3 (rpr3) in chinese hamster ovary cells (cho-cells). the part of pr3 cdna that encoded the active form of pr3 was s...