The Library

Evidence that diacylglycerol acyltransferase 1 (DGAT1) has dual membrane topology in the endoplasmic reticulum of HepG2 cells

Tools

Wurie, Haja R., Buckett, L., Zammit, Victor A. and UNSPECIFIED. (2011) Evidence that diacylglycerol acyltransferase 1 (DGAT1) has dual membrane topology in the endoplasmic reticulum of HepG2 cells. Journal of Biological Chemistry, Vol.286 (No.42). pp. 36238-36247. ISSN 0021-9258

Full text not available from this repository.

Official URL: http://dx.doi.org/10.1074/jbc.M111.251900

Abstract

Triacylglycerol (TAG) synthesis and secretion are important functions of the liver which have major impacts on health, as over-accumulation of TAG within the liver (steatosis) or hypersecretion of TAG within very-low-density lipoproteins (VLDL) both have deleterious metabolic consequences. Two diacylglycerol acyltransferases (DGATs 1 and 2) can catalyse the final step in the synthesis of TAG from diacylglycerol (DAG) which has been suggested to play an important role in the transfer of the glyceride moiety across the endoplasmic reticular membrane for (re)synthesis of TAG on the lumenal aspect of the endoplasmic reticular (ER) membrane [Owen, M., Corstorphine, C.G., and V.A. Zammit (1997) Biochem. J. 323, 17-21 ]. Recent topographical studies suggested that the oligomeric enzyme DGAT1 is exclusively lumen-facing (latent) in the ER membrane. By contrast, in the present study, using two specific inhibitors of human DGAT1, we present evidence that DGAT1 has a dual topology within the ER of HepG2 cells, with approximately equal DGAT1 activities exposed on the cytosolic and lumenal aspects of the ER membrane. This was confirmed by the observation of the loss of both overt (partial) and latent (total) DGAT activity in microsomes prepared from livers of Dgat1 -/- mice. Conformational differences between DGAT1 molecules having the different topologies were indicated by the markedly different sensitivities of the overt DGAT1 to one of the inhibitors. These data suggest that DGAT1 belongs to the family of oligomeric membrane proteins that adopt a dual membrane topology.

Item Type:

Journal Article

Subjects:

Q Science > QH Natural history > QH301 Biology
Q Science > QR Microbiology
R Medicine > RC Internal medicine

Divisions:

Faculty of Medicine > Warwick Medical School

Library of Congress Subject Headings (LCSH):

Diglycerides, Acyltransferases, Insulin resistance, Endoplasmic reticulum

Journal or Publication Title:

Journal of Biological Chemistry

Publisher:

The American Society for Biochemistry and Molecular Biology

ISSN:

0021-9258

Official Date:

21 October 2011

Dates:

Date	Event
21 October 2011	Published

Volume:

Vol.286

Number:

No.42

Page Range:

pp. 36238-36247

Identification Number:

10.1074/jbc.M111.251900

Status:

Peer Reviewed

Publication Status:

Published

Access rights to Published version:

Restricted or Subscription Access

Funder:

Biotechnology and Biological Sciences Research Council (Great Britain) (BBSRC), AstraZeneca (Firm)

References:

1. Gotto, A. M., Jr. (1998) Am. J. Cardiol. 82, 22Q–25Q
2. Zammit, V. A., Waterman, I. J., Topping, D., and McKay, G. (2001) J. Nutr.
131, 2074–2077
3. Erion, D. M., and Shulman, G. I. (2010) Nat. Med. 16, 400–402
4. Cases, S., Smith, S. J., Zheng, Y. W., Myers, H. M., Lear, S. R., Sande, E.,
Novak, S., Collins, C., Welch, C. B., Lusis, A. J., Erickson, S. K., and Farese,
R. V., Jr. (1998) Proc. Natl. Acad. Sci. U.S.A. 95, 13018–13023
5. Cases, S., Stone, S. J., Zhou, P., Yen, E., Tow, B., Lardizabal, K. D., Voelker,
T., and Farese, R. V., Jr. (2001) J. Biol. Chem. 276, 38870–38876
6. Zammit, V. A., Buckett, L. K., Turnbull, A. V., Wure, H., and Proven, A.
(2008) Pharmacol. Ther. 118, 295–302
7. Olofsson, S. O., Asp, L., and Bore´n, J. (1999) Curr. Opin. Lipidol. 10,
341–346
8. Lankester, D., Brown, A., and Zammit, V. (1998) J. Lipid Res. 39,
1889–1895
9. Owen, M. R., Corstorphine, C. C., and Zammit, V. A. (1997) Biochem. J.
323, 17–21
10. Gouffi, K., Ge´rard, F., Santini, C. L., and Wu, L. F. (2004) J. Biol. Chem. 279,
11608–11615
11. Waterman, I. J., Price, N. T., and Zammit, V. A. (2002) J. Lipid Res. 43,
1555–1562
12. Waterman, I. J., and Zammit, V. A. (2002) Diabetes 51, 1708–1713
13. Yang, L. Y., Kuksis, A., Myher, J. J., and Steiner, G. (1995) J. Lipid Res. 36,
125–136
14. Broadway, N., Pease, R., and Saggerson, E. (1999) in Current Views of Fatty
acid Oxidation and Ketogenesis: From Organelles to Point Mutations
(Quant, P., and Eaton, S., eds) pp. 59–68, Luwer Academic/Plenum Publishers,
New York
15. Broadway, N. M., and Saggerson, E. D. (1995) Biochem. J. 310, 989–995
16. Abo-Hashema, K. A., Cake, M. H., Power, G. W., and Clarke, D. (1999)
J. Biol. Chem. 274, 35577–35582
17. Yamazaki, T., Sasaki, E., Kakinuma, C., Yano, T., Miura, S., and Ezaki, O.
(2005) J. Biol. Chem. 280, 21506–21514
18. McFie, P. J., Stone, S. L., Banman, S. L., and Stone, S. J. (2010) J. Biol. Chem.
285, 37377–37387
19. Stone, S. J., Levin, M. C., and Farese, R. V., Jr. (2006) J. Biol. Chem. 281,
40273–40282
20. Kuerschner, L., Moessinger, C., and Thiele, C. (2008) Traffic 9, 338–352
21. McFie, P. J., Banman, S. L., Kary, S., and Stone, S. J. (2011) J. Biol. Chem.
286, 28235–28246
22. Herker, E., Harris, C., Hernandez, C., Carpentier, A., Kaehlcke, K., Rosenberg,
A. R., Farese, R. V., Jr., and Ott, M. (2010) Nat. Med. 16, 1295–1298
23. Adeli, K. (1994) J. Biol. Chem. 269, 9166–9175
24. Bell, R. M., Ballas, L. M., and Coleman, R. A. (1981) J. Lipid Res. 22,
391–403
25. Boon, M. R., and Zammit, V. A. (1988) Biochem. J. 249, 645–652
26. Owen, M., and Zammit, V. A. (1997) Biochem. Soc. Trans. 25, 21S
27. Kolbusz, M. A., ter Horst, R., Slotboom, D. J., and Lolkema, J. S. (2010) J.
Mol. Biol. 402, 127–138
28. Hinkle, P. M., and Sebag, J. A. (2009) Mol. Cell. Endocrinol. 300, 25–31
29. Levy, D. (1996) Essays Biochem. 31, 49–60
30. Rapp, M., Granseth, E., Seppa¨la¨, S., and von Heijne, G. (2006) Nat. Struct.
Mol. Biol. 13, 112–116
31. Lolkema, J. S., Dobrowolski, A., and Slotboom, D. J. (2008) J. Mol. Biol.
378, 596–606
32. Sebag, J. A., and Hinkle, P. M. (2009) J. Biol. Chem. 284, 610–618
33. Chen, Y. J., Pornillos, O., Lieu, S., Ma, C., Chen, A. P., and Chang, G. (2007)
Proc. Natl. Acad. Sci. U.S.A. 104, 18999–19004