Sterols regulate processing of carbohydrate chains of wild-type SREBP cleavage-activating protein (SCAP), but not sterol-resistant mutants Y298C or D443N

Research output: Contribution to journalArticle

104 Citations (Scopus)

Abstract

SREBP cleavage activating protein (SCAP), a membrane-bound glycoprotein, regulates the proteolytic activation of sterol regulatory element binding proteins (SREBPs), which are membrane-bound transcription factors that control lipid synthesis in animal cells. SCAP-stimulated proteolysis releases active fragments of SREBPs from membranes of the endoplasmic reticulum and allows them to enter the nucleus where they activate transcription. SteroIs such as 25-hydroxycholesterol inactivate SCAP, suppressing SREBP proteolysis and turning off cholesterol synthesis. We here report the isolation of Chinese hamster ovary cells with a point mutation in SCAP (Y298c) that renders the protein resistant to inhibition by 25-hydroxycholesterol. Like the previously described D443N mutation, the Y298C mutation occurs within the putative sterol-sensing domain, which is part of the polytopic membrane attachment region of SCAP. Cells that express SCAP(Y298C) continued to process SREBPs in the presence of 25-hydroxycholesterol and hence they resisted killing by this sterol. In wild-type Chinese hamster ovary cells the N-linked carbohydrate chains of SCAP were mostly in the endoglycosidase H- sensitive form when cells were grown in medium containing 25- hydroxycholesterol. In contrast, when cells were grown in sterol-depleted medium, these chains were converted to an endoglycosidase H-resistant form. 25-Hydroxycholesterol had virtually no effect in cells expressing SCAP(D443N) or SCAP(Y298C). The relation between this regulated carbohydrate processing to the SCAP-regulated proteolysis of SREBP remains to be explored.

Original languageEnglish (US)
Pages (from-to)12848-12853
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume95
Issue number22
DOIs
StatePublished - Oct 27 1998

Fingerprint

Sterol Regulatory Element Binding Proteins
Sterols
Carbohydrates
Proteins
Proteolysis
Glycoside Hydrolases
Cricetulus
Membranes
Ovary
SREBP cleavage-activating protein
Mutation
Membrane Glycoproteins
Point Mutation
Endoplasmic Reticulum
Transcription Factors
Cholesterol
25-hydroxycholesterol

Keywords

  • Cholesterol
  • Endoplasmic reticulum
  • Golgi apparatus
  • Sterol regulatory element binding protein
  • Sterol-sensing domain

ASJC Scopus subject areas

  • Genetics
  • General

Cite this

@article{08bbf891042b4026a04f70ededd5fe81,
title = "Sterols regulate processing of carbohydrate chains of wild-type SREBP cleavage-activating protein (SCAP), but not sterol-resistant mutants Y298C or D443N",
abstract = "SREBP cleavage activating protein (SCAP), a membrane-bound glycoprotein, regulates the proteolytic activation of sterol regulatory element binding proteins (SREBPs), which are membrane-bound transcription factors that control lipid synthesis in animal cells. SCAP-stimulated proteolysis releases active fragments of SREBPs from membranes of the endoplasmic reticulum and allows them to enter the nucleus where they activate transcription. SteroIs such as 25-hydroxycholesterol inactivate SCAP, suppressing SREBP proteolysis and turning off cholesterol synthesis. We here report the isolation of Chinese hamster ovary cells with a point mutation in SCAP (Y298c) that renders the protein resistant to inhibition by 25-hydroxycholesterol. Like the previously described D443N mutation, the Y298C mutation occurs within the putative sterol-sensing domain, which is part of the polytopic membrane attachment region of SCAP. Cells that express SCAP(Y298C) continued to process SREBPs in the presence of 25-hydroxycholesterol and hence they resisted killing by this sterol. In wild-type Chinese hamster ovary cells the N-linked carbohydrate chains of SCAP were mostly in the endoglycosidase H- sensitive form when cells were grown in medium containing 25- hydroxycholesterol. In contrast, when cells were grown in sterol-depleted medium, these chains were converted to an endoglycosidase H-resistant form. 25-Hydroxycholesterol had virtually no effect in cells expressing SCAP(D443N) or SCAP(Y298C). The relation between this regulated carbohydrate processing to the SCAP-regulated proteolysis of SREBP remains to be explored.",
keywords = "Cholesterol, Endoplasmic reticulum, Golgi apparatus, Sterol regulatory element binding protein, Sterol-sensing domain",
author = "Axel Nohturfft and Brown, {Michael S.} and Goldstein, {Joseph L.}",
year = "1998",
month = "10",
day = "27",
doi = "10.1073/pnas.95.22.12848",
language = "English (US)",
volume = "95",
pages = "12848--12853",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
number = "22",

}

TY - JOUR

T1 - Sterols regulate processing of carbohydrate chains of wild-type SREBP cleavage-activating protein (SCAP), but not sterol-resistant mutants Y298C or D443N

AU - Nohturfft, Axel

AU - Brown, Michael S.

AU - Goldstein, Joseph L.

PY - 1998/10/27

Y1 - 1998/10/27

N2 - SREBP cleavage activating protein (SCAP), a membrane-bound glycoprotein, regulates the proteolytic activation of sterol regulatory element binding proteins (SREBPs), which are membrane-bound transcription factors that control lipid synthesis in animal cells. SCAP-stimulated proteolysis releases active fragments of SREBPs from membranes of the endoplasmic reticulum and allows them to enter the nucleus where they activate transcription. SteroIs such as 25-hydroxycholesterol inactivate SCAP, suppressing SREBP proteolysis and turning off cholesterol synthesis. We here report the isolation of Chinese hamster ovary cells with a point mutation in SCAP (Y298c) that renders the protein resistant to inhibition by 25-hydroxycholesterol. Like the previously described D443N mutation, the Y298C mutation occurs within the putative sterol-sensing domain, which is part of the polytopic membrane attachment region of SCAP. Cells that express SCAP(Y298C) continued to process SREBPs in the presence of 25-hydroxycholesterol and hence they resisted killing by this sterol. In wild-type Chinese hamster ovary cells the N-linked carbohydrate chains of SCAP were mostly in the endoglycosidase H- sensitive form when cells were grown in medium containing 25- hydroxycholesterol. In contrast, when cells were grown in sterol-depleted medium, these chains were converted to an endoglycosidase H-resistant form. 25-Hydroxycholesterol had virtually no effect in cells expressing SCAP(D443N) or SCAP(Y298C). The relation between this regulated carbohydrate processing to the SCAP-regulated proteolysis of SREBP remains to be explored.

AB - SREBP cleavage activating protein (SCAP), a membrane-bound glycoprotein, regulates the proteolytic activation of sterol regulatory element binding proteins (SREBPs), which are membrane-bound transcription factors that control lipid synthesis in animal cells. SCAP-stimulated proteolysis releases active fragments of SREBPs from membranes of the endoplasmic reticulum and allows them to enter the nucleus where they activate transcription. SteroIs such as 25-hydroxycholesterol inactivate SCAP, suppressing SREBP proteolysis and turning off cholesterol synthesis. We here report the isolation of Chinese hamster ovary cells with a point mutation in SCAP (Y298c) that renders the protein resistant to inhibition by 25-hydroxycholesterol. Like the previously described D443N mutation, the Y298C mutation occurs within the putative sterol-sensing domain, which is part of the polytopic membrane attachment region of SCAP. Cells that express SCAP(Y298C) continued to process SREBPs in the presence of 25-hydroxycholesterol and hence they resisted killing by this sterol. In wild-type Chinese hamster ovary cells the N-linked carbohydrate chains of SCAP were mostly in the endoglycosidase H- sensitive form when cells were grown in medium containing 25- hydroxycholesterol. In contrast, when cells were grown in sterol-depleted medium, these chains were converted to an endoglycosidase H-resistant form. 25-Hydroxycholesterol had virtually no effect in cells expressing SCAP(D443N) or SCAP(Y298C). The relation between this regulated carbohydrate processing to the SCAP-regulated proteolysis of SREBP remains to be explored.

KW - Cholesterol

KW - Endoplasmic reticulum

KW - Golgi apparatus

KW - Sterol regulatory element binding protein

KW - Sterol-sensing domain

UR - http://www.scopus.com/inward/record.url?scp=0032573056&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032573056&partnerID=8YFLogxK

U2 - 10.1073/pnas.95.22.12848

DO - 10.1073/pnas.95.22.12848

M3 - Article

C2 - 9789003

AN - SCOPUS:0032573056

VL - 95

SP - 12848

EP - 12853

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

SN - 0027-8424

IS - 22

ER -