spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online 12 August 2008
doi: 10.1242/jcs.026153

Journal of Cell Science 121, 2921-2929 (2008)
Published by The Company of Biologists 2008
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplementary Material
Right arrow All Versions of this Article:
jcs.026153v1
121/17/2921    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Related articles in JCS
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Google Scholar
Right arrow Articles by Orlicky, D. J.
Right arrow Articles by McManaman, J. L.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Orlicky, D. J.
Right arrow Articles by McManaman, J. L.

Research Article

Multiple functions encoded by the N-terminal PAT domain of adipophilin

David J. Orlicky1, Greg DeGala2, Carrie Greenwood2, Elise S. Bales2, Tanya D. Russell2,3 and James L. McManaman2,3,4,5,*

1 Department of Pathology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
2 Department of Obstetrics and Gynecology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
3 Graduate Program in Molecular Biology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
4 Graduate Program in Reproductive Sciences, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
5 Graduate Program in Cell Biology, Stem Cells and Development, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA

* Author for correspondence (e-mail: jim.mcmanaman{at}uchsc.edu)

Accepted 16 June 2008

Adipophilin (ADPH), a member of the perilipin family of cytoplasmic lipid droplet (CLD)-binding proteins, is crucially dependent on triglyceride synthesis for stability. We have used cell lines expressing full-length or N-terminally modified forms of ADPH to investigate the role of the N-terminus in regulating ADPH stability and interactions with CLD. Full-length ADPH was unstable and could not be detected on CLDs unless cultures were incubated with oleic acid (OA) to stimulate triglyceride synthesis, or were treated with MG132 to block proteasomal degradation. By contrast, ADPH lacking amino acids 1-89 ({Delta} 2,3 ADPH), or N-terminally GFP-tagged full-length ADPH, was stable in the absence of OA or MG132, as was the closely related protein TIP47. However, none of these proteins localized to CLDs unless OA was added to the culture medium. Furthermore, immunofluorescence analysis showed that TIP47 localization to CLDs was prevented by full-length ADPH, but not by {Delta} 2,3 ADPH. These results suggest that the N-terminal region of ADPH mediates proteasomal degradation and access of TIP47 to the CLD surface and possibly contributes to CLD stability. Chimeras of ADPH and TIP47, generated by swapping their N- and C-terminal halves, showed that these properties are specific to ADPH.

Key words: Adipophilin (ADPH; ADFP), TIP47 (M6PRBP1), Lipid droplets, Proteasome, Domain


Related articles in JCS:

...but PAT breaks it down

JCS 2008 121: 1703. [Full Text]  





© The Company of Biologists Ltd 2008