Skip to main content
SpringerLink
Log in

Sterol carrier protein‐2:Not just for cholesterol any more

  • Published:
Molecular and Cellular Biochemistry Aims and scope Submit manuscript

Abstract

Although sterol carrier protein-2 (SCP-2) mediates cholesterol esterification in L-cell fibroblasts and stimulates an accumulation of cholesterol in these cells, a potential role for SCP-2 in fatty acid uptake and trafficking has not been appreciated. Certainly, recent experiments have shown that SCP-2 binds fatty acids in vitro with an affinity similar to that observed for fatty acid binding proteins. Because of the ubiquitous tissue distribution of SCP-2, as opposed to the specific distribution of fatty acid binding proteins, as well as the need for fatty acid trafficking in all cells, I have recently proposed that SCP-2 is the universal fatty acid trafficking protein. This supposition is based on a number of observations made with L-cell fibroblasts expressing either the 13.2 kDa SCP-2 or the 15 kDa proSCP-2. In L-cells expressing the 13.2 kDa SCP-2, fluorescent fatty acid uptake was increased by 10–30% depending upon the probe used. In 15 kDa proSCP-2 expressing cells, fluorescent fatty acid uptake was increased 20–40% depending upon the probe used. However, only expression of the 15 kDa pro-SCP-2 increased the cytoplasmic diffusion of the fluorescent fatty acid. Expression of either protein increased the uptake of [3H]-oleic acid 1.9-fold compared to control, with targeting of [3H]-oleic acid for esterification into cholesteryl esters. The 13.2 kDa SCP-2 did target a significant amount of [3H]-oleic acid for esterification into the triacylglycerol pool. Expression of either protein markedly reduced total cellular phospholipid levels, however both proteins increased cholesteryl ester levels. Interestingly, expression of the 15 kDa proSCP-2 decreased ethanolamine plasmalogen levels with a concomitant increase in choline plasmalogen. Expression of both proteins increased PUFA content of the phospholipids, although this effect was greater in 15 kDa proSCP-2 expressing cells. Hence, expression of SCP-2 increased fatty acid uptake and targeted fatty acid to unique lipid pools, suggesting that SCP-2 may effectively serve as universal fatty acid binding and trafficking protein.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Murphy EJ, Schroeder F: Sterol carrier protein-2 mediated cholesterol esterification in transfected L-cell fibroblasts. Biochim Biophys Acta 1345: 283–292, 1997

    Google Scholar 

  2. Moncecchi D, Murphy EJ, Prows DR, Schroeder F: Sterol carrier protein-2 expression in mouse L-cell fibroblasts alters cholesterol uptake. Biochem Biophys A 1302: 110–116, 1996

    Google Scholar 

  3. Schroeder F, Frolov A, Schoer J, Gallegos A, Atshaves BP, Stolwich NJ, Scott AI, Kier AB: Intracellular cholesterol binding proteins, cholesterol transport, and membrane domains. In: D. Freeman, T.Y. Chang (eds). Intracellular Cholesterol Trafficking. Kluwer Academic Publishers, Boston, MA, 1998, pp 231–234

    Google Scholar 

  4. Ohba T, Rennert H, Pfeifer SM, He Z, Yamamoto R, Holt JA, Billheimer JT, Strauss JF III: The structure of the human sterol carrier protein x/ sterol carrier protein 2 gene (SCP2). Genomics 24: 370–374, 1994

    Google Scholar 

  5. Seedorf U, Assmann G: Cloning, expression, and nucleotide sequence of rat liver sterol carrier protein 2 cDNAs. J Biol Chem 266: 630–636, 1991

    Google Scholar 

  6. Moncecchi D, Pastuszyn A, Scallen TJ: cDNA sequence and bacterial expression of mouse liver sterol carrier protein-2. J Biol Chem 266: 9885–9892, 1991

    Google Scholar 

  7. . Yamamoto R, Kallen CB, Babalola GO, Rennert H, Billheimer JT, Strauss JF III: Cloning and expression of a cDNA encoding human sterol carrier protein 2. Proc Natl Acad Sci USA 88: 463–467, 1991

    Google Scholar 

  8. . Ossendorp BC, van Heusden GPH, Wirtz KWA: The amino acid sequence of rat liver non-specific lipid transfer protein (sterol carrier protein 2) is present in a high molecular weight protein: Evidence from cDNA analysis. Biochem Biophys Res Commun 168: 631–636, 1990

    Google Scholar 

  9. . Matsuura JE, George HJ, Ramachandran N, Alvarez JG, Strauss JF III, Billheimer JT: Expression of the mature and the pro-form of human sterol carrier protein 2 in Escherichia coli alters bacterial lipids. Biochemistry 32: 567–572, 1993

    Google Scholar 

  10. Seedorf U, Scheek S, Engel T, Steif C, Hinz H-J, Assmann G: Structure-activity studies on human sterol carrier protein 2. J Biol Chem 269: 2613–2618, 1994

    Google Scholar 

  11. Schroeder F, Frolov A, Starodub O, Atshaves BB, Russell W, Petrescu A, Huang H, Gallegos AM, McIntosh A, Tahotna D, Russell DH, Billheimer JT, Baum CL, Kier AB: Pro-sterol carrier protein-2. Role of the n-terminal presequence in structure, function, and peroxisomal targeting. J Biol Chem 275: 25547–25555, 2000

    Google Scholar 

  12. van Heusden GPH, Bos K, Raetz CRH, Wirtz KWA: Chinese hamster ovary cells deficient in peroxisomes lack the nonspecific lipid transfer protein (sterol carrier protein 2). J Biol Chem 265: 4105–4110, 1990

    Google Scholar 

  13. Keller GA, Scallen TJ, Clarke D, Maher PA, Krisans SK, Singer SJ: Subcellular localization of sterol carrier protein-2 in rat hepatocytes: Its primary localization to peroxisomes. J Cell Biol 108: 1353–1361, 1989

    Google Scholar 

  14. Starodub O, Jolly CA, Atshaves BP, Roths JB, Murphy EJ, Kier AB, Schroeder F: Sterol carrier protein-2 localization in endoplasmic reticulum and role in phospholipid formation. Am J Physiol Cell Physiol 279: C1259–C1269, 2000

    Google Scholar 

  15. Conneely OM, Headon DR, Olson CD, Ungar F, Dempsey ME: Intramitochondrial movement of adrenal sterol carrier protein with cholesterol in response to corticotropin. Proc Natl Acad Sci USA 81: 2970–2974, 1984

    Google Scholar 

  16. Vahouny GV, Dennis P, Chanderbhan R, Fiskum G, Noland BJ, Scallen TJ: Sterol carrier protein 2 (SCP2)-mediated transfer of cholesterol to mitochondrial inner membranes. Biochem Biophys Res Commun 122: 509–515, 1984

    Google Scholar 

  17. Van der Krift TP, Leunissen J, Teerlink T, van Heusden GPH, Verkleij AJ, Wirtz KWA: Ultrastructural localization of a peroxisomal protein in rat liver using the specific antibody against the non-specific lipid transfer protein (sterol carrier protein 2). Biochim Biophys Acta 812: 387–392, 1985

    Google Scholar 

  18. Murphy EJ: Sterol carrier protein-2 expression increases NBD-stearate uptake and cytoplasmic diffusion in L cells. Am J Physiol 275: G237–G243, 1998

    Google Scholar 

  19. Murphy EJ, Stiles T, Schroeder F: Sterol carrier protein-2 expression alters phospholipid content and fatty acyl composition in L-cell fibroblasts. J Lipid Res 41: 788–796, 2000

    Google Scholar 

  20. Colles SM, Woodford JK, Moncecchi D, Myers-Payne SC, McLean LR, Billheimer JT, Schroeder F: Cholesterol interaction with recombinant human sterol carrier protein-2. Lipids 30: 795–803, 1995

    Google Scholar 

  21. Gadella TWJ Jr, Bastiaens PIH, Visser AJWG, Wirtz KWA: Shape and lipid-binding site of the nonspecific lipid-transfer protein (sterol carrier protein 2): A steady-state and time-resolved fluorescence study. Biochemistry 30: 5555–5564, 1991

    Google Scholar 

  22. Stolwich NJ, Frolov A, Petrescu A, Scott AI, Billheimer JT, Schroeder F: Holo-sterol carrier protein-2: 13C-NMR investigation of cholesterol and fatty acid binding sites. J Biol Chem 274: 35425–35433, 1999

    Google Scholar 

  23. Schroeder F, Myers-Payne SC, Billheimer JT, Wood WG: Probing the ligand binding sites of fatty acid and sterol carrier proteins: effects of ethanol. Biochemistry 34: 11919–11927, 1995

    Google Scholar 

  24. Stolwich NJ, Frolov A, Atshaves B, Murphy EJ, Jolly CA, Billheimer JT, Scott AI, Schroeder F: The sterol carrier protein-2 fatty acid binding site: An NMR, circular dichroic and fluorescence spectroscopic determination. Biochemistry 36: 1719–1729, 1997

    Google Scholar 

  25. Gallegos AM, Atshaves BP, Storey SM, Starodub O, Petrescu AD, Huang H, McIntosh AL, Martin GG, Chao H, Kier AB, Schroeder F: Gene structure, intracellular localization, and functional roles of sterol carrier protein-2. Prog Lipid Res 40: 498–563, 2001

    Google Scholar 

  26. Frolov A, Cho TH, Billheimer JT, Schroeder F: Sterol carrier protein-2, a new fatty acyl coenzyme A-binding protein. J Biol Chem 271: 31878–31884, 1996

    Google Scholar 

  27. Dansen TB, Westerman J, Wouters FS, Wanders JR, van Hoek A, Gadella TW Jr, Wirtz KW: High-affinity binding of very-long-chain fatty acyl-CoA esters to the peroxisomal non-specific lipid-transfer protein (sterol carrier protein-2). Biochem J 339: 193–199, 1999

    Google Scholar 

  28. van Amerongen A, Demel RA, Westerman J, Wirtz KWA: Transfer of cholesterol and oxysterol derivatives by the nonspecific lipid transfer protein (sterol carrier protein 2): A study on its mode of action. Biochim Biophys Acta 1004: 36–43, 1989

    Google Scholar 

  29. Butko P, Hapala I, Scallen TJ, Schroeder F: Acidic phospholipids strikingly potentiate sterol carrier protein 2 mediated intermembrane sterol transfer. Biochemistry 29: 4070–4077, 1990

    Google Scholar 

  30. Frolov A, Woodford JK, Murphy EJ, Billheimer JT, Schroeder F: Spontaneous and protein-mediated sterol transfer between intracellular membranes. J Biol Chem 271: 16075–16083, 1996

    Google Scholar 

  31. García FL, Szyperski T, Dyer JH, Choinowski T, Seedorf U, Hauser H, Wüthrich K: NMR structure of the sterol carrier protein-2: Implications for the biological role. J Mol Biol 295: 595–603, 2000

    Google Scholar 

  32. Choinowski T, Hauser H, Piontek K: Structure of sterol carrier protein 2 at 1.8 Å resolution reveals a hydrophobic tunnel suitable for lipid binding. Biochemistry 39: 1897–1902, 2000

    Google Scholar 

  33. Atshaves BP, Petrescu AD, Starodub O, Roths JB, Kier AB, Schroeder F: Expression and intracellular processing of the 58 kDa sterol carrier protein-2/3-oxoacyl-CoA thiolase in transfected mouse L-cell fibroblasts. J Lipid Res 40: 610–622, 1999

    Google Scholar 

  34. van Amerongen A, Teerlink T, van Heusden GPH, Wirtz KWA: The non-specific lipid transfer protein (sterol carrier protein 2) from rat and bovine liver. Chem Phys Lipids 38: 195–204, 1985

    Google Scholar 

  35. Higuchi K: An improved chemically define culture medium for strain L mouse cells based on growth responses to graded levels of nutrients including iron and zinc. J Cell Physiol 75: 65–72, 1970

    Google Scholar 

  36. Hara A, Radin NS: Lipid extraction of tissues with a low-toxicity solvent. Anal Biochem 90: 420–426, 1978

    Google Scholar 

  37. Murphy EJ, Rosenberger TA, Horrocks LA: Effects of maturation on the phospholipid and phospholipid fatty acid compositions in primary rat cortical astrocyte cell cultures. Neurochem Res 22: 1205–1213, 1997

    Google Scholar 

  38. Demediuk P, Anderson DK, Horrocks LA, Means ED: Mechanical damage to murine neuronal-enriched cultures during harvesting: Effects on free fatty acids, diglycerides, Na+,K+-ATPase, and lipid peroxidation. In Vitro Cell Dev Biol 21: 569–574, 1985

    Google Scholar 

  39. Bradford M: A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem 72: 248–254, 1976

    Google Scholar 

  40. Jones M, Keenan RW, Horowitz P: Use of 6-p-toluidino-2-naphthalenesulfonic acid to quantitate lipids after thin-layer chromatography. J Chromatogr 237: 522–524, 1982

    Google Scholar 

  41. Rosenberger, TA, Oki, J, Purdon, AD, Rapoport, SI, Murphy, EJ: Rapid synthesis and turnover of brain microsomal ether phospholipids in the adult rat. J Lipid Res 43: 59–68, 2002

    Google Scholar 

  42. Murphy EJ, Prows DR, Jefferson JR, Schroeder F: Liver fatty acid binding protein expression in transfected fibroblasts stimulates fatty acid uptake and metabolism. Biochim Biophys Acta 1301: 191–196, 1996

    Google Scholar 

  43. Prows DR, Murphy EJ, Schroeder F: Intestinal and liver fatty acid binding proteins differentially affect fatty acid uptake and esterification in L-cells. Lipids 30: 907–910, 1995

    Google Scholar 

  44. Prows DR, Murphy EJ, Moncecchi D, Schroeder F: Intestinal fatty acid-binding protein expression stimulates fibroblast fatty acid esterification. Chem Phys Lipids 84: 47–56, 1996

    Google Scholar 

  45. Jolly CA, Hubbell T, Behnke WD, Schroeder F: Fatty acid binding protein: Stimulation of microsomal phosphatidic acid formation. Arch Biochem Biophys 341: 112–121, 1997

    Google Scholar 

  46. Jolly CA, Murphy EJ, Schroeder F: Differential influence of rat liver fatty acid binding protein isoforms on phospholipid fatty acid composition: Phosphatidic acid biosynthesis and phospholipid fatty acid remodeling. Biochim Biophys Acta 1390: 258–268, 1998

    Google Scholar 

  47. Hubbell T, Behnke WD, Woodford JK, Schroeder F: Recombinant liver fatty acid binding protein interacts with fatty acyl-coenzyme A. Biochemistry 33: 3327–3335, 1994

    Google Scholar 

  48. Murphy EJ: L-FABP and L-FABP expression increases NBD-stearate uptake and cytoplasmic diffusion in L cells. Am J Physiol 275: G244–G249, 1998

    Google Scholar 

  49. Gallegos AM, Schoer JK, Starodub O, Kier AB, Billheimer JT, Schroeder F: A potential role for sterol carrier protein-2 in cholesterol transfer to mitochondria. Chem Phys Lipids 105: 9–29, 2000

    Google Scholar 

  50. Murphy EJ, Prows D, Stiles T, Schroeder F: Phospholipid and phospholipid fatty acid composition of L-cell fibroblast: Effect of intestinal and liver fatty acid binding protein. Lipids 35: 729–738, 2000

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Pharmacology, Physiology and Therapeutics, University of North Dakota, 501 North Columbia Road, Room 3700, Grand Forks, ND, 58203, USA

    Eric J. Murphy

Authors
  1. Eric J. Murphy
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Murphy, E.J. Sterol carrier protein‐2:Not just for cholesterol any more. Mol Cell Biochem 239, 87–93 (2002). https://doi.org/10.1023/A:1020580706912

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1023/A:1020580706912

Search

Navigation