Abstract
Mutants resistant to compactin, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, have been previously isolated from the Chinese hamster V79 cell line. Two compactin-resistant mutants, MF-1 and MF-2, show altered responses to human low-density lipoprotein (LDL). Accumulation of fluorescentlabeled LDL was much reduced. Ligand blotting showed LDL receptor activity in MF-1 and MF-2 cells of about one half to one third that of V79. Internalization and degradation of LDL in MF-1 or MF-2 cells were about one tenth those in V79 cells, suggesting that the LDL binding as well as the LDL internalization of the compactin-resistant clones was altered. Down-regulation of LDL receptor activity as well as hydroxymethylglutaryl CoA reductase was observed in V79 cells treated with LDL, while there appeared to be much less down-regulation in MF-1 and MF-2 cells. Using anti-LDL receptor antibody, MF-1 and MF-2 cells were found to produce smaller-sized mature forms of LDL receptor: the molecular mass of the mutant LDL receptor was 3-5 kDa smaller than that of the parental LDL receptor. Altered O-linked oligosaccharides or amino acid sequence might account for the decreased molecular mass and aberrant properties of the LDL receptor in MF-1 and MF-2.
| Original language | English |
|---|---|
| Pages (from-to) | 575-586 |
| Number of pages | 12 |
| Journal | Biochimica et Biophysica Acta (BBA)/Lipids and Lipid Metabolism |
| Volume | 921 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 1987 Oct 17 |
| Externally published | Yes |
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Keywords
- Compactin-resistant mutant
- Endocytosis
- Hydroxymethylglutaryl-CoA reductase (Chinese hamster cells)
- LDL receptor
ASJC Scopus subject areas
- Biochemistry
- Biophysics
- Endocrinology
Cite this
Altered function and structure of low-density lipoprotein receptor in compactin (ML236B)-resistant mutants of Chinese hamster cells. / Takashi, Yoshida; Yoshimura, Akihiko; Mayumi, Ono; Shigeaki, Hori; Michinori, Waki; Michihiko, Kuwano.
In: Biochimica et Biophysica Acta (BBA)/Lipids and Lipid Metabolism, Vol. 921, No. 3, 17.10.1987, p. 575-586.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Altered function and structure of low-density lipoprotein receptor in compactin (ML236B)-resistant mutants of Chinese hamster cells
AU - Takashi, Yoshida
AU - Yoshimura, Akihiko
AU - Mayumi, Ono
AU - Shigeaki, Hori
AU - Michinori, Waki
AU - Michihiko, Kuwano
PY - 1987/10/17
Y1 - 1987/10/17
N2 - Mutants resistant to compactin, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, have been previously isolated from the Chinese hamster V79 cell line. Two compactin-resistant mutants, MF-1 and MF-2, show altered responses to human low-density lipoprotein (LDL). Accumulation of fluorescentlabeled LDL was much reduced. Ligand blotting showed LDL receptor activity in MF-1 and MF-2 cells of about one half to one third that of V79. Internalization and degradation of LDL in MF-1 or MF-2 cells were about one tenth those in V79 cells, suggesting that the LDL binding as well as the LDL internalization of the compactin-resistant clones was altered. Down-regulation of LDL receptor activity as well as hydroxymethylglutaryl CoA reductase was observed in V79 cells treated with LDL, while there appeared to be much less down-regulation in MF-1 and MF-2 cells. Using anti-LDL receptor antibody, MF-1 and MF-2 cells were found to produce smaller-sized mature forms of LDL receptor: the molecular mass of the mutant LDL receptor was 3-5 kDa smaller than that of the parental LDL receptor. Altered O-linked oligosaccharides or amino acid sequence might account for the decreased molecular mass and aberrant properties of the LDL receptor in MF-1 and MF-2.
AB - Mutants resistant to compactin, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, have been previously isolated from the Chinese hamster V79 cell line. Two compactin-resistant mutants, MF-1 and MF-2, show altered responses to human low-density lipoprotein (LDL). Accumulation of fluorescentlabeled LDL was much reduced. Ligand blotting showed LDL receptor activity in MF-1 and MF-2 cells of about one half to one third that of V79. Internalization and degradation of LDL in MF-1 or MF-2 cells were about one tenth those in V79 cells, suggesting that the LDL binding as well as the LDL internalization of the compactin-resistant clones was altered. Down-regulation of LDL receptor activity as well as hydroxymethylglutaryl CoA reductase was observed in V79 cells treated with LDL, while there appeared to be much less down-regulation in MF-1 and MF-2 cells. Using anti-LDL receptor antibody, MF-1 and MF-2 cells were found to produce smaller-sized mature forms of LDL receptor: the molecular mass of the mutant LDL receptor was 3-5 kDa smaller than that of the parental LDL receptor. Altered O-linked oligosaccharides or amino acid sequence might account for the decreased molecular mass and aberrant properties of the LDL receptor in MF-1 and MF-2.
KW - Compactin-resistant mutant
KW - Endocytosis
KW - Hydroxymethylglutaryl-CoA reductase (Chinese hamster cells)
KW - LDL receptor
UR - http://www.scopus.com/inward/record.url?scp=0023270883&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0023270883&partnerID=8YFLogxK
U2 - 10.1016/0005-2760(87)90086-5
DO - 10.1016/0005-2760(87)90086-5
M3 - Article
VL - 921
SP - 575
EP - 586
JO - Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids
JF - Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids
SN - 1388-1981
IS - 3
ER -