Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Original Article
  • Published:

Akt regulates nuclear/cytoplasmic localization of tuberin

Abstract

The autosomal dominantly inherited disease tuberous sclerosis (TSC) affects 1 in 6000 individuals and is characterized by the development of tumors, named hamartomas, in different organs. TSC1, encoding hamartin, and TSC2, encoding tuberin are tumor suppressor genes responsible for TSC. Hamartin and tuberin form a complex, of which tuberin is assumed to be the functional component. The TSC proteins have been implicated in the control of cell cycle by activating the cyclin-dependent kinase inhibitor p27 and in cell size regulation by inhibiting the mammalian target of rapamycin (mTOR)/p70S6K cascade. Phosphorylation of S939 and T1462 by Akt downregulates tuberin's potential to inhibit mTOR/p70S6K. Here, we show that this tuberin phosphorylation by Akt does not affect tuberin-mediated control of p27 protein amounts. This demonstrates that regulating p27 protein amounts and mTOR/p70S6K are separable functions of tuberin. Furthermore, we found that phosphorylation by Akt triggers upregulation of cytoplasmic and downregulation of nuclear tuberin. In cycling cells with high Akt activity, tuberin is predominantly localized to the cytoplasm. In arrested G0 cells with downregulated Akt activity, a significant proportion of tuberin is localized to the nucleus. Upon re-entry into the normal ongoing cell cycle, nuclear localization of tuberin is downregulated parallel to the activation of Akt. Recently, the mTOR/p70S6K cascade has been demonstrated to exist in both the cytoplasm and nucleus. We here also found that tuberin harbors the potential to regulate p70S6K activity in both the cytoplasm and nucleus. This description of functional tuberin in the cytoplasm and the nucleus together with our observation of Akt-controlled and cell cycle-regulated tuberin localization are of particular interest for a further understanding of tuberin's function as a gate keeper of the G0 cell status as well as of Akt's activity to control cell proliferation.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8

Similar content being viewed by others

References

  • Astrinidis A, Henske EP . (2005). Oncogene 24: 7475–7481.

  • Astrinidis A, Senapedis W, Henske EP . (2006). Hum Mol Genet 15: 287–297.

  • Bachmann RA, Kim J-H, Wu A-L, Park I-H, Chen J . (2006). J Biol Chem 281: 7357–7363.

  • Chong-Kopera H, Inoki K, Li Y, Zhu T, Garcia-Gonzalo FR, Rosa JL et al. (2006). J Biol Chem 281: 8313–8316.

  • Dan HC, Sun M, Yang L, Feldman RI, Sui X-M, Ou CC et al. (2002). J Biol Chem 277: 35364–35370.

  • Dostie J, Lejbkowicz F, Sonenberg N . (2000). J Cell Biol 148: 239–247.

  • Dufner A, Thomas G . (1999). Exp Cell Res 253: 100–109.

  • Fujita N, Sato S, Katayama K, Tsuruo T . (2002). J Biol Chem 277: 28706–28713.

  • Furuya F, Hanover JA, Cheng S-Y . (2006). Proc Natl Acad Sci USA 103: 1780–1785.

  • Goncharova EA, Goncharov DA, Eszterhas AW, Hunter DS, Glassberg MK, Yeung RS et al. (2002). J Biol Chem 277: 30958–30967.

  • Henry KW, Yuan X, Koszewski NJ, Onda H, Kwiatkowski DJ, Noonan DJ . (1998). J Biol Chem 273: 20535–20539.

  • Inoki K, Li Y, Zhu T, Wu J, Guan K-L . (2002). Nat Cell Biol 4: 648–657.

  • Inoki K, Zhu T, Guan K-L . (2003). Cell 115: 577–590.

  • Kim JE, Chen J . (2000). Proc Natl Acad Sci USA 97: 14340–14345.

  • Kwiatkowski DJ . (2003). Ann Hum Genet 67: 87–96.

  • Liang J, Zubovitz J, Petrocelli T, Kotchetkov R, Connor MK, Han K et al. (2002). Nat Med 8: 1153–1160.

  • Lejbkowicz F, Goyer C, Darveau A, Neron S, Lemieux R, Sonenberg N . (1992). Proc Natl Acad Sci USA 89: 9612–9616.

  • Li Y, Corradetti MN, Inoki K, Guan K-L . (2003). Trends Biochem Sci 29: 32–38.

  • Liu H, Radisky DC, Nelson CM, Zhang H, Fata JE, Roth RA et al. (2006). Proc Natl Acad Sci USA 103: 4134–4139.

  • Lou D, Griffith N, Noonan DJ . (2001). Mol Cell Biol Res Commun 4: 374–380.

  • Ma L, Zhenbang C, Erdjument-Bromage H, Tempst P, Pandolfi PP . (2005). Cell 121: 179–193.

  • Manning BD, Tee AR, Logsdon MN, Blenis J, Cantley LC . (2002). Mol Cell 10: 151–162.

  • Miloloza A, Rosner M, Nellist M, Halley D, Bernaschek G, Hengstschläger M . (2000). Hum Mol Genet 9: 1721–1727.

  • Nellist M, van Slegtenhorst MA, Goedbloed M, van den Ouweland AM, Hally DJ, van der Sluijs P . (1999). J Biol Chem 274: 35647–35652.

  • Pan D, Dong J, Zhang Y, Gao X . (2004). Trends Cell Biol 14: 78–85.

  • Pasumarthi KBS, Nakajima H, Nakajima HO, Jing S, Field LJ . (2000). Circ Res 86: 1069–1077.

  • Potter CJ, Pedraza LG, Xu T . (2002). Nat Cell Biol 4: 658–665.

  • Rosner M, Freilinger A, Hengstschläger M . (2004). Amino Acids 27: 119–128.

  • Rosner M, Hengstschläger M . (2004). J Biol Chem 279: 48707–48715.

  • Rosner M, Hofer K, Kubista K, Hengstschläger M . (2003). Oncogene 22: 4786–4798.

  • Roux PP, Ballif BA, Anjum R, Gygi SP, Blenis J . (2004). Proc Natl Acad Sci USA 101: 13489–13494.

  • Shin I, Yakes FM, Rojo F, Shin NY, Bakin AV, Baselga J et al. (2002). Nat Med 8: 1145–1152.

  • Soucek T, Hölzl G, Bernaschek G, Hengstschläger M . (1998a). Oncogene 16: 2197–2204.

  • Soucek T, Pusch O, Wienecke R, DeClue JE, Hengstschläger M . (1997). J Biol Chem 272: 29301–29308.

  • Soucek T, Yeung RS, Hengstschläger M . (1998b). Proc Natl Acad Sci USA 95: 15653–15658.

  • Tee AR, Fingar DC, Manning BD, Kwiatkowski DJ, Cantley LC, Blenis J . (2002). Proc Natl Acad Sci USA 99: 13571–13576.

  • The European Chromosome 16 Tuberous Sclerosis Consortium (1993). Cell 75: 1305–1315.

  • The TSC1 Consortium (1997). Science 277: 805–808.

  • Viglietto G, Motti ML, Bruni P, Melillo RM, D’Alessio A, Califano D et al. (2002). Nat Med 8: 1136–1144.

  • Wienecke R, Maize JC, Shoarinejad F, Vass WC, Reed J, Binfacino JS et al. (1996). Oncogene 13: 913–923.

  • Wullschleger S, Loewith R, Hall MN . (2006). Cell 124: 471–484.

  • Xiao G-H, Shoarinejad F, Jin F, Golemis EA, Yeung RS . (1997). J Biol Chem 272: 6097–6100.

  • Zhang X, Shu L, Hosoi H, Murti KG, Houghton PJ . (2002). J Biol Chem 277: 28127–28134.

Download references

Acknowledgements

We thank Drs B Manning and J Blenis for reagents. This research has been supported by the FWF Austrian Science Fund (P18894-B12).

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to M Hengstschläger.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Rosner, M., Freilinger, A. & Hengstschläger, M. Akt regulates nuclear/cytoplasmic localization of tuberin. Oncogene 26, 521–531 (2007). https://doi.org/10.1038/sj.onc.1209812

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/sj.onc.1209812

Keywords

This article is cited by

Search

Quick links