Insensitivity of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity to low-density lipoprotein in concanavalin-A-resistant Chinese-hamster ovary cells

1982 ◽  
Vol 2 (9) ◽  
pp. 645-652 ◽  
Author(s):  
Thor Borgford ◽  
David N. Burton
Keyword(s):  
Concanavalin A ◽  
Chinese Hamster Ovary ◽  
Coenzyme A ◽  
Reductase Activity ◽  
Chinese Hamster Ovary Cells ◽  
Low Density Lipoprotein ◽  
Chinese Hamster ◽  
Density Lipoprotein ◽  
Low Density ◽  
Ovary Cells

scholarly journals Unusual forms of low density lipoprotein receptors in hamster cell mutants with defects in the receptor structural gene.

1986 ◽  
Vol 102 (5) ◽  
pp. 1567-1575 ◽  
Author(s):  
K F Kozarsky ◽  
H A Brush ◽  
M Krieger
Keyword(s):  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Low Density Lipoprotein ◽  
Chinese Hamster ◽  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Low Density ◽  
Wild Type ◽  
Ovary Cells ◽  
Ldl Receptors

The structure and processing of low density lipoprotein (LDL) receptors in wild-type and LDL receptor-deficient mutant Chinese hamster ovary cells was examined using polyclonal anti-receptor antibodies. As previously reported for human LDL receptors, the LDL receptors in wild-type Chinese hamster ovary cells were synthesized as precursors which were extensively processed by glycosylation to a mature form. In the course of normal receptor turnover, an apparently unglycosylated portion of the cysteine-rich N-terminal LDL binding domain of the receptor is proteolytically removed. The LDL receptor-deficient mutants fall into four complementation groups, ldlA, ldlB, ldlC, and ldlD; results of the analysis of ldlB, ldlC, and ldlD mutants are described in the accompanying paper (Kingsley, D. M., K. F. Kozarsky, M. Segal, and M. Krieger, 1986, J. Cell. Biol, 102:1576-1585). Analysis of ldlA cells has identified three classes of mutant alleles at the ldlA locus: null alleles, alleles that code for normally processed receptors that cannot bind LDL, and alleles that code for abnormally processed receptors. The abnormally processed receptors were continually converted to novel unstable intracellular intermediates. We also identified a compound-heterozygous mutant and a heterozygous revertant which indicate that the ldlA locus is diploid. In conjunction with other genetic and biochemical data, the finding of multiple mutant forms of the LDL receptor in ldlA mutants, some of which appeared together in the same cell, confirm that the ldlA locus is the structural gene for the LDL receptor.

scholarly journals Regulation of low density lipoprotein receptor activity in Chinese hamster ovary cells transfected with the c-fmsgene

FEBS Letters ◽  
1994 ◽  
Vol 356 (1) ◽  
pp. 72-75
Author(s):  
Koji Yamamoto ◽  
Hitoshi Shimano ◽  
Toshimori Inaba ◽  
Takanari Gotoda ◽  
Kenji Harada ◽  
...  
Keyword(s):  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Low Density Lipoprotein ◽  
Chinese Hamster ◽  
Density Lipoprotein ◽  
Receptor Activity ◽  
Low Density ◽  
Lipoprotein Receptor ◽  
Ovary Cells ◽  
Density Lipoprotein Receptor

scholarly journals Chinese Hamster Ovary Cells Expressing a Novel Type of Acetylated Low Density Lipoprotein Receptor

1995 ◽  
Vol 270 (4) ◽  
pp. 1921-1927 ◽  
Author(s):  
Masayoshi Fukasawa ◽  
Kotaro Hirota ◽  
Hideki Adachi ◽  
Keiko Mimura ◽  
Kimiko Murakami-Murofushi ◽  
...  
Keyword(s):  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Low Density Lipoprotein ◽  
Chinese Hamster ◽  
Density Lipoprotein ◽  
Low Density ◽  
Lipoprotein Receptor ◽  
Low Density Lipoprotein Receptor ◽  
Ovary Cells ◽  
Density Lipoprotein Receptor

Expression and regulation of human low-density lipoprotein receptors in Chinese hamster ovary cells

Nature ◽  
1984 ◽  
Vol 307 (5953) ◽  
pp. 742-745 ◽  
Author(s):  
Robert D. Sege ◽  
Karen Kozarsky ◽  
David L. Nelson ◽  
Monty Krieger
Keyword(s):  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Low Density Lipoprotein ◽  
Chinese Hamster ◽  
Density Lipoprotein ◽  
Low Density ◽  
Lipoprotein Receptors ◽  
Ovary Cells

scholarly journals Sterols accelerate degradation of hamster 3-hydroxy-3-methylglutaryl coenzyme A reductase encoded by a constitutively expressed cDNA.

1985 ◽  
Vol 5 (4) ◽  
pp. 634-641 ◽  
Author(s):  
D J Chin ◽  
G Gil ◽  
J R Faust ◽  
J L Goldstein ◽  
M S Brown ◽  
...  
Keyword(s):  
Coenzyme A ◽  
Reductase Activity ◽  
Chinese Hamster Ovary Cells ◽  
Low Density Lipoprotein ◽  
Chinese Hamster ◽  
Density Lipoprotein ◽  
Simian Virus 40 ◽  
Low Density ◽  
Reductase Mrna ◽  
Coenzyme A Reductase

A recombinant plasmid containing a full-length cDNA for hamster 3-hydroxy-3-methylglutaryl coenzyme A reductase was introduced by calcium phosphate-mediated transfection into UT-2 cells, a mutant line of Chinese hamster ovary cells that lack 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and thus require low density lipoprotein-cholesterol and mevalonate for growth. We selected a line of permanently transfected cells, designated TR-36 cells, that expressed high levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and thus grew in the absence of low density lipoprotein and mevalonate. Constitutive synthesis of reductase mRNA in TR-36 cells was driven by the simian virus 40 early promoter, and therefore the mRNA was not suppressed by sterols, such as 25-hydroxycholesterol or cholesterol derived from low density lipoprotein, which normally suppresses transcription of reductase mRNA when the reductase gene is driven by its own promoter. Although TR-36 cells continued to synthesize large amounts of reductase mRNA and protein in the presence of sterols, reductase activity declined by 50 to 60%. This decline was caused by a twofold increase in the rate of degradation of preformed enzyme molecules. The current data demonstrate that sterols accelerate the degradation of reductase protein independently of any inhibitory effect on the synthesis of the protein.

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