Transcriptional regulation of phagocytosis-induced membrane biogenesis by sterol regulatory element binding proteins

Adam B. Castoreno, Yan Wang, Walter Stockinger, Larissa A. Jarzylo, Hong Du, Joanne C. Pagnon, Eugenie C. Shieh, Axel Nohturfft

Research output: Contribution to journalArticle

54 Citations (Scopus)

Abstract

In the process of membrane biogenesis several dozen proteins must operate in precise concert to generate ≈100 lipids at appropriate concentrations. To study the regulation of bilayer assembly in a cell cycle-independent manner, we have exploited the fact that phagocytes replenish membranes expended during particle engulfment in a rapid phase of lipid synthesis. In response to phagocytosis of latex beads, human embryonic kidney 293 cells synthesized cholesterol and phospholipids at amounts equivalent to the surface area of the internalized particles. Lipid synthesis was accompanied by increased transcription of several lipogenic proteins, including the low-density lipoprotein receptor, enzymes required for cholesterol synthesis (3-hydroxy-3-methylglutaryl CoA synthase, 3-hydroxy-3-methylglutaryl CoA reductase), and fatty acid synthase. Phagocytosis triggered the proteolytic activation of two lipogenic transcription factors, sterol regulatory element binding protein-1a (SREBP-1a) and SREBP-2. Proteolysis of SREBPs coincided with the appearance of their transcriptionally active N termini in the nucleus and 3-fold activation of an SREBP-specific reporter gene. In previous studies with cultured cells, proteolytic activation of SREBP-1a and SREBP-2 has been observed in response to selective starvation of cells for cholesterol and unsaturated fatty acids. However, under the current conditions, SREBP-1a and SREBP-2 are induced without lipid deprivation. SREBP activation is inhibited by high levels of the SREBP-interacting proteins Insig1 or the cytosolic domain of SREBP cleavage-activating protein. Upon overexpression of these proteins, phagocytosis-induced transcription and lipid synthesis were blocked. These results identify SREBPs as essential regulators of membrane biogenesis and provide a useful system for further studies on membrane homeostasis.

Original languageEnglish (US)
Pages (from-to)13129-13134
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume102
Issue number37
DOIs
StatePublished - Sep 13 2005
Externally publishedYes

Fingerprint

Sterol Regulatory Element Binding Proteins
Phagocytosis
Sterol Regulatory Element Binding Protein 1
Lipids
Membranes
Cholesterol
Hydroxymethylglutaryl CoA Reductases
Fatty Acid Synthases
Proteins
LDL Receptors
Phagocytes
Starvation
Unsaturated Fatty Acids
Microspheres
Reporter Genes
Proteolysis
Cultured Cells
Phospholipids
Cell Cycle
Homeostasis

Keywords

  • Gene regulation
  • Lipid synthesis
  • Organelle biogenesis

ASJC Scopus subject areas

  • General

Cite this

Transcriptional regulation of phagocytosis-induced membrane biogenesis by sterol regulatory element binding proteins. / Castoreno, Adam B.; Wang, Yan; Stockinger, Walter; Jarzylo, Larissa A.; Du, Hong; Pagnon, Joanne C.; Shieh, Eugenie C.; Nohturfft, Axel.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 102, No. 37, 13.09.2005, p. 13129-13134.

Research output: Contribution to journalArticle

Castoreno, Adam B. ; Wang, Yan ; Stockinger, Walter ; Jarzylo, Larissa A. ; Du, Hong ; Pagnon, Joanne C. ; Shieh, Eugenie C. ; Nohturfft, Axel. / Transcriptional regulation of phagocytosis-induced membrane biogenesis by sterol regulatory element binding proteins. In: Proceedings of the National Academy of Sciences of the United States of America. 2005 ; Vol. 102, No. 37. pp. 13129-13134.
@article{102e68e9b9fa4549833980c24f134118,
title = "Transcriptional regulation of phagocytosis-induced membrane biogenesis by sterol regulatory element binding proteins",
abstract = "In the process of membrane biogenesis several dozen proteins must operate in precise concert to generate ≈100 lipids at appropriate concentrations. To study the regulation of bilayer assembly in a cell cycle-independent manner, we have exploited the fact that phagocytes replenish membranes expended during particle engulfment in a rapid phase of lipid synthesis. In response to phagocytosis of latex beads, human embryonic kidney 293 cells synthesized cholesterol and phospholipids at amounts equivalent to the surface area of the internalized particles. Lipid synthesis was accompanied by increased transcription of several lipogenic proteins, including the low-density lipoprotein receptor, enzymes required for cholesterol synthesis (3-hydroxy-3-methylglutaryl CoA synthase, 3-hydroxy-3-methylglutaryl CoA reductase), and fatty acid synthase. Phagocytosis triggered the proteolytic activation of two lipogenic transcription factors, sterol regulatory element binding protein-1a (SREBP-1a) and SREBP-2. Proteolysis of SREBPs coincided with the appearance of their transcriptionally active N termini in the nucleus and 3-fold activation of an SREBP-specific reporter gene. In previous studies with cultured cells, proteolytic activation of SREBP-1a and SREBP-2 has been observed in response to selective starvation of cells for cholesterol and unsaturated fatty acids. However, under the current conditions, SREBP-1a and SREBP-2 are induced without lipid deprivation. SREBP activation is inhibited by high levels of the SREBP-interacting proteins Insig1 or the cytosolic domain of SREBP cleavage-activating protein. Upon overexpression of these proteins, phagocytosis-induced transcription and lipid synthesis were blocked. These results identify SREBPs as essential regulators of membrane biogenesis and provide a useful system for further studies on membrane homeostasis.",
keywords = "Gene regulation, Lipid synthesis, Organelle biogenesis",
author = "Castoreno, {Adam B.} and Yan Wang and Walter Stockinger and Jarzylo, {Larissa A.} and Hong Du and Pagnon, {Joanne C.} and Shieh, {Eugenie C.} and Axel Nohturfft",
year = "2005",
month = "9",
day = "13",
doi = "10.1073/pnas.0506716102",
language = "English (US)",
volume = "102",
pages = "13129--13134",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
number = "37",

}

TY - JOUR

T1 - Transcriptional regulation of phagocytosis-induced membrane biogenesis by sterol regulatory element binding proteins

AU - Castoreno, Adam B.

AU - Wang, Yan

AU - Stockinger, Walter

AU - Jarzylo, Larissa A.

AU - Du, Hong

AU - Pagnon, Joanne C.

AU - Shieh, Eugenie C.

AU - Nohturfft, Axel

PY - 2005/9/13

Y1 - 2005/9/13

N2 - In the process of membrane biogenesis several dozen proteins must operate in precise concert to generate ≈100 lipids at appropriate concentrations. To study the regulation of bilayer assembly in a cell cycle-independent manner, we have exploited the fact that phagocytes replenish membranes expended during particle engulfment in a rapid phase of lipid synthesis. In response to phagocytosis of latex beads, human embryonic kidney 293 cells synthesized cholesterol and phospholipids at amounts equivalent to the surface area of the internalized particles. Lipid synthesis was accompanied by increased transcription of several lipogenic proteins, including the low-density lipoprotein receptor, enzymes required for cholesterol synthesis (3-hydroxy-3-methylglutaryl CoA synthase, 3-hydroxy-3-methylglutaryl CoA reductase), and fatty acid synthase. Phagocytosis triggered the proteolytic activation of two lipogenic transcription factors, sterol regulatory element binding protein-1a (SREBP-1a) and SREBP-2. Proteolysis of SREBPs coincided with the appearance of their transcriptionally active N termini in the nucleus and 3-fold activation of an SREBP-specific reporter gene. In previous studies with cultured cells, proteolytic activation of SREBP-1a and SREBP-2 has been observed in response to selective starvation of cells for cholesterol and unsaturated fatty acids. However, under the current conditions, SREBP-1a and SREBP-2 are induced without lipid deprivation. SREBP activation is inhibited by high levels of the SREBP-interacting proteins Insig1 or the cytosolic domain of SREBP cleavage-activating protein. Upon overexpression of these proteins, phagocytosis-induced transcription and lipid synthesis were blocked. These results identify SREBPs as essential regulators of membrane biogenesis and provide a useful system for further studies on membrane homeostasis.

AB - In the process of membrane biogenesis several dozen proteins must operate in precise concert to generate ≈100 lipids at appropriate concentrations. To study the regulation of bilayer assembly in a cell cycle-independent manner, we have exploited the fact that phagocytes replenish membranes expended during particle engulfment in a rapid phase of lipid synthesis. In response to phagocytosis of latex beads, human embryonic kidney 293 cells synthesized cholesterol and phospholipids at amounts equivalent to the surface area of the internalized particles. Lipid synthesis was accompanied by increased transcription of several lipogenic proteins, including the low-density lipoprotein receptor, enzymes required for cholesterol synthesis (3-hydroxy-3-methylglutaryl CoA synthase, 3-hydroxy-3-methylglutaryl CoA reductase), and fatty acid synthase. Phagocytosis triggered the proteolytic activation of two lipogenic transcription factors, sterol regulatory element binding protein-1a (SREBP-1a) and SREBP-2. Proteolysis of SREBPs coincided with the appearance of their transcriptionally active N termini in the nucleus and 3-fold activation of an SREBP-specific reporter gene. In previous studies with cultured cells, proteolytic activation of SREBP-1a and SREBP-2 has been observed in response to selective starvation of cells for cholesterol and unsaturated fatty acids. However, under the current conditions, SREBP-1a and SREBP-2 are induced without lipid deprivation. SREBP activation is inhibited by high levels of the SREBP-interacting proteins Insig1 or the cytosolic domain of SREBP cleavage-activating protein. Upon overexpression of these proteins, phagocytosis-induced transcription and lipid synthesis were blocked. These results identify SREBPs as essential regulators of membrane biogenesis and provide a useful system for further studies on membrane homeostasis.

KW - Gene regulation

KW - Lipid synthesis

KW - Organelle biogenesis

UR - http://www.scopus.com/inward/record.url?scp=24944522320&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=24944522320&partnerID=8YFLogxK

U2 - 10.1073/pnas.0506716102

DO - 10.1073/pnas.0506716102

M3 - Article

VL - 102

SP - 13129

EP - 13134

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 - 37

ER -