Inhibitor of apoptosis-stimulating protein of p53 (iASPP) prevents senescence and is required for epithelial stratification
Edited by Alan R. Fersht, MRC Laboratory of Molecular Biology, Cambridge, UK, Cambridge, United Kingdom, and approved August 9, 2011 (received for review February 10, 2011)
Abstract
Inhibitor of apoptosis-stimulating protein of p53 (iASPP) is the most ancient member of the ASPP family of proteins and an evolutionarily conserved inhibitor of p53. iASPP is also a binding partner and negative regulator of p65RelA. Because p65RelA and the p53 family members often have opposite effects in controlling cell fate, it is important to understand the cellular context in which iASPP can regulate their activities. To address this question and to study the biological importance of iASPP in vivo, we generated a transgenic mouse in which iASPP expression is controlled by the Cre/loxP recombination system. We observed that iASPP is able to prevent premature cellular senescence in mouse embryonic fibroblasts. iASPP loss resulted in increased differentiation of primary keratinocytes both in vitro and in vivo. In stratified epithelia, nuclear iASPP often colocalized with p63 in the nuclei of basal keratinocytes. Consistent with this, iASPP bound p63 and inhibited the transcriptional activity of both TAp63α and ΔNp63α in vitro and influenced the expression level of p63-regulated genes such as loricrin and involucrin in vivo. In contrast, under the same conditions, p65RelA was frequently expressed as a cytoplasmic protein in the suprabasal layers of stratified epithelia and rarely colocalized with nuclear iASPP. Thus, iASPP is likely to control epithelial stratification by regulating p63's transcriptional activity, rather than p65RelA's. This study identifies iASPP as an inhibitor of senescence and a key player in controlling epithelial stratification.
Acknowledgments
We thank Mark Shipman for his technical assistance and Dr. Claire Beveridge for critical reading of the manuscript. This work was mainly funded by the Ludwig Institute for Cancer Research. E.C. and G.M. acknowledge funding from Associazione Italiana Ricerca sul Cancro, Telethon and the Medical Research Council.
Supporting Information
Supporting Information (PDF)
Supporting Information
- Download
- 1.55 MB
References
1
AJ Levine, M Oren, The first 30 years of p53: Growing ever more complex. Nat Rev Cancer 9, 749–758 (2009).
2
VA Belyi, AJ Levine, One billion years of p53/p63/p73 evolution. Proc Natl Acad Sci USA 106, 17609–17610 (2009).
3
D Bergamaschi, et al., iASPP oncoprotein is a key inhibitor of p53 conserved from worm to human. Nat Genet 33, 162–167 (2003).
4
A Sullivan, X Lu, ASPP: A new family of oncogenes and tumour suppressor genes. Br J Cancer 96, 196–200 (2007).
5
F Murray-Zmijewski, DP Lane, JC Bourdon, p53/p63/p73 isoforms: An orchestra of isoforms to harmonise cell differentiation and response to stress. Cell Death Differ 13, 962–972 (2006).
6
DK Carroll, et al., p63 regulates an adhesion programme and cell survival in epithelial cells. Nat Cell Biol 8, 551–561 (2006).
7
AA Mills, et al., p63 is a p53 homologue required for limb and epidermal morphogenesis. Nature 398, 708–713 (1999).
8
A Yang, et al., p63 is essential for regenerative proliferation in limb, craniofacial and epithelial development. Nature 398, 714–718 (1999).
9
A Yang, et al., p73-deficient mice have neurological, pheromonal and inflammatory defects but lack spontaneous tumours. Nature 404, 99–103 (2000).
10
D Bergamaschi, et al., ASPP1 and ASPP2: Common activators of p53 family members. Mol Cell Biol 24, 1341–1350 (2004).
11
KM Kampa, et al., Apoptosis-stimulating protein of p53 (ASPP2) heterozygous mice are tumor-prone and have attenuated cellular damage-response thresholds. Proc Natl Acad Sci USA 106, 4390–4395 (2009).
12
V Vives, et al., ASPP2 is a haploinsufficient tumor suppressor that cooperates with p53 to suppress tumor growth. Genes Dev 20, 1262–1267 (2006).
13
RA Robinson, X Lu, EY Jones, C Siebold, Biochemical and structural studies of ASPP proteins reveal differential binding to p53, p63, and p73. Structure 16, 259–268 (2008).
14
JP Yang, M Hori, T Sanda, T Okamoto, Identification of a novel inhibitor of nuclear factor-kappaB, RelA-associated inhibitor. J Biol Chem 274, 15662–15670 (1999).
15
AS Baldwin, JC Azizkhan, DE Jensen, AA Beg, LR Coodly, Induction of NF-kappa B DNA-binding activity during the G0-to-G1 transition in mouse fibroblasts. Mol Cell Biol 11, 4943–4951 (1991).
16
CS Duckett, ND Perkins, K Leung, AB Agranoff, GJ Nabel, Cytokine induction of nuclear factor kappa B in cycling and growth-arrested cells. Evidence for cell cycle-independent activation. J Biol Chem 270, 18836–18840 (1995).
17
AA Beg, WC Sha, RT Bronson, S Ghosh, D Baltimore, Embryonic lethality and liver degeneration in mice lacking the RelA component of NF-kappa B. Nature 376, 167–170 (1995).
18
M Dohn, S Zhang, X Chen, p63alpha and DeltaNp63alpha can induce cell cycle arrest and apoptosis and differentially regulate p53 target genes. Oncogene 20, 3193–3205 (2001).
19
X Guo, et al., TAp63 induces senescence and suppresses tumorigenesis in vivo. Nat Cell Biol 11, 1451–1457 (2009).
20
E Candi, et al., p63 is upstream of IKK alpha in epidermal development. J Cell Sci 119, 4617–4622 (2006).
21
BJ Herron, et al., A mutation in NFkB interacting protein 1 results in cardiomyopathy and abnormal skin development in wa3 mice. Hum Mol Genet 14, 667–677 (2005).
22
F Schwenk, U Baron, K Rajewsky, A cre-transgenic mouse strain for the ubiquitous deletion of loxP-flanked gene segments including deletion in germ cells. Nucleic Acids Res 23, 5080–5081 (1995).
23
AK Indra, et al., Temporally-controlled site-specific mutagenesis in the basal layer of the epidermis: Comparison of the recombinase activity of the tamoxifen-inducible Cre-ER(T) and Cre-ER(T2) recombinases. Nucleic Acids Res 27, 4324–4327 (1999).
24
H Hennings, K Holbrook, P Steinert, S Yuspa, Growth and differentiation of mouse epidermal cells in culture: Effects of extracellular calcium. Curr Probl Dermatol 10, 3–25 (1980).
25
A Yang, et al., p63, a p53 homolog at 3q27-29, encodes multiple products with transactivating, death-inducing, and dominant-negative activities. Mol Cell 2, 305–316 (1998).
26
MI Koster, S Kim, AA Mills, FJ DeMayo, DR Roop, p63 is the molecular switch for initiation of an epithelial stratification program. Genes Dev 18, 126–131 (2004).
27
E Fuchs, H Green, Changes in keratin gene expression during terminal differentiation of the keratinocyte. Cell 19, 1033–1042 (1980).
28
DW Owens, VG Brunton, EK Parkinson, MC Frame, E-cadherin at the cell periphery is a determinant of keratinocyte differentiation in vitro. Biochem Biophys Res Commun 269, 369–376 (2000).
29
CA Squier, MJ Kremer, Biology of oral mucosa and esophagus. J Natl Cancer Inst Monogr 29, 7–15 (2001).
30
M Osada, et al., Differential recognition of response elements determines target gene specificity for p53 and p63. Mol Cell Biol 25, 6077–6089 (2005).
31
E Candi, et al., Differential roles of p63 isoforms in epidermal development: Selective genetic complementation in p63 null mice. Cell Death Differ 13, 1037–1047 (2006).
32
F Murray-Zmijewski, EA Slee, X Lu, A complex barcode underlies the heterogeneous response of p53 to stress. Nat Rev Mol Cell Biol 9, 702–712 (2008).
33
E Candi, et al., p63 in epithelial development. Cell Mol Life Sci 65, 3126–3133 (2008).
34
KE King, et al., deltaNp63alpha functions as both a positive and a negative transcriptional regulator and blocks in vitro differentiation of murine keratinocytes. Oncogene 22, 3635–3644 (2003).
35
K Nylander, et al., Differential expression of p63 isoforms in normal tissues and neoplastic cells. J Pathol 198, 417–427 (2002).
36
X Su, et al., TAp63 prevents premature aging by promoting adult stem cell maintenance. Cell Stem Cell 5, 64–75 (2009).
37
P Descargues, AK Sil, M Karin, IKKalpha, a critical regulator of epidermal differentiation and a suppressor of skin cancer. EMBO J 27, 2639–2647 (2008).
Information & Authors
Information
Published in
Classifications
Copyright
Freely available online through the PNAS open access option.
Submission history
Published online: September 19, 2011
Published in issue: October 4, 2011
Acknowledgments
We thank Mark Shipman for his technical assistance and Dr. Claire Beveridge for critical reading of the manuscript. This work was mainly funded by the Ludwig Institute for Cancer Research. E.C. and G.M. acknowledge funding from Associazione Italiana Ricerca sul Cancro, Telethon and the Medical Research Council.
Notes
This article is a PNAS Direct Submission.
Authors
Competing Interests
The authors declare no conflict of interest.
Metrics & Citations
Metrics
Altmetrics
Citations
Cite this article
Inhibitor of apoptosis-stimulating protein of p53 (iASPP) prevents senescence and is required for epithelial stratification, Proc. Natl. Acad. Sci. U.S.A.
108 (40) 16645-16650,
https://doi.org/10.1073/pnas.1102292108
(2011).
Copied!
Copying failed.
Export the article citation data by selecting a format from the list below and clicking Export.
Cited by
Loading...
View Options
View options
PDF format
Download this article as a PDF file
DOWNLOAD PDFLogin options
Check if you have access through your login credentials or your institution to get full access on this article.
Personal login Institutional LoginRecommend to a librarian
Recommend PNAS to a LibrarianPurchase options
Purchase this article to access the full text.