Previous Article | Next Article 
Molecular and Cellular Biology, January 2006, p. 192-198, Vol. 26, No. 1
0270-7306/06/$08.00+0 doi:10.1128/MCB.26.1.192-198.2006
Copyright © 2006, American Society for Microbiology. All Rights Reserved.
Tissue-Specific Differences of p53 Inhibition by Mdm2 and Mdm4
Jason D. Grier,
Shunbin Xiong,
Ana C. Elizondo-Fraire,
John M. Parant, and
Guillermina Lozano*
The University of Texas Graduate School of Biomedical Sciences and Department of Molecular Genetics, Section of Cancer Genetics, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030
Received 20 June 2005/
Returned for modification 31 July 2005/
Accepted 12 October 2005
The function of the p53 tumor suppressor to inhibit proliferation or initiate apoptosis is often abrogated in tumor cells. Mdm2 and its homolog, Mdm4, are critical inhibitors of p53 that are often overexpressed in human tumors. In mice, loss of Mdm2 or Mdm4 leads to embryonic lethal phenotypes that are completely rescued by concomitant loss of p53. To examine the role of Mdm2 and Mdm4 in a temporal and tissue-specific manner and to determine the relationships of these inhibitors to each other, we generated conditional alleles. We deleted Mdm2 and Mdm4 in cardiomyocytes, since proliferation and apoptosis are important processes in heart development. Mice lacking Mdm2 in the heart were embryonic lethal and showed defects at the time recombination occurred. A critical number of cardiomyocytes were lost by embryonic day 13.5, resulting in heart failure. This phenotype was completely rescued by deletion of p53. Mice lacking Mdm4 in the heart were born at the correct ratio and appeared to be normal. Our studies provide the first direct evidence that Mdm2 can function in the absence of Mdm4 to regulate p53 activity in a tissue-specific manner. Moreover, Mdm4 cannot compensate for the loss of Mdm2 in heart development.
* Corresponding author. Mailing address: Department of Molecular Genetics, Section of Cancer Genetics, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030. Phone: (713) 834-6386. Fax: (713) 834-6380. E-mail:
gglozano{at}mdanderson.org.
Supplemental material for this article may be found at http://mcb.asm.org/.
These authors contributed equally to this work.
Molecular and Cellular Biology, January 2006, p. 192-198, Vol. 26, No. 1
0022-538X/06/$08.00+0 doi:10.1128/MCB.26.1.192-198.2006
Copyright © 2006, American Society for Microbiology. All Rights Reserved.
This article has been cited by other articles:
-
Pikkarainen, S., Kennedy, R. A., Marshall, A. K., Tham, E. L., Lay, K., Kriz, T. A., Handa, B. S., Clerk, A., Sugden, P. H.
(2009). Regulation of Expression of the Rat Orthologue of Mouse Double Minute 2 (MDM2) by H2O2-induced Oxidative Stress in Neonatal Rat Cardiac Myocytes. J. Biol. Chem.
284: 27195-27210
[Abstract]
[Full Text]
-
Barboza, J. A., Iwakuma, T., Terzian, T., El-Naggar, A. K., Lozano, G.
(2008). Mdm2 and Mdm4 Loss Regulates Distinct p53 Activities. Mol Cancer Res
6: 947-954
[Abstract]
[Full Text]
-
Terzian, T., Wang, Y., Van Pelt, C. S., Box, N. F., Travis, E. L., Lozano, G.
(2007). Haploinsufficiency of Mdm2 and Mdm4 in Tumorigenesis and Development. Mol. Cell. Biol.
27: 5479-5485
[Abstract]
[Full Text]
-
Xiong, S., Van Pelt, C. S., Elizondo-Fraire, A. C., Fernandez-Garcia, B., Lozano, G.
(2007). Loss of Mdm4 Results in p53-Dependent Dilated Cardiomyopathy. Circulation
115: 2925-2930
[Abstract]
[Full Text]
-
Singh, R. K., Iyappan, S., Scheffner, M.
(2007). Hetero-oligomerization with MdmX Rescues the Ubiquitin/Nedd8 Ligase Activity of RING Finger Mutants of Mdm2. J. Biol. Chem.
282: 10901-10907
[Abstract]
[Full Text]
-
Maetens, M., Doumont, G., Clercq, S. D., Francoz, S., Froment, P., Bellefroid, E., Klingmuller, U., Lozano, G., Marine, J.-C.
(2007). Distinct roles of Mdm2 and Mdm4 in red cell production. Blood
109: 2630-2633
[Abstract]
[Full Text]
-
Marine, J.-C. W., Dyer, M. A., Jochemsen, A. G.
(2007). MDMX: from bench to bedside. J. Cell Sci.
120: 371-378
[Abstract]
[Full Text]
-
Barbieri, E., Mehta, P., Chen, Z., Zhang, L., Slack, A., Berg, S., Shohet, J. M.
(2006). MDM2 inhibition sensitizes neuroblastoma to chemotherapy-induced apoptotic cell death.. Molecular Cancer Therapeutics
5: 2358-2365
[Abstract]
[Full Text]
-
Francoz, S., Froment, P., Bogaerts, S., De Clercq, S., Maetens, M., Doumont, G., Bellefroid, E., Marine, J.-C.
(2006). Mdm4 and Mdm2 cooperate to inhibit p53 activity in proliferating and quiescent cells in vivo. Proc. Natl. Acad. Sci. USA
103: 3232-3237
[Abstract]
[Full Text]
-
Xiong, S., Van Pelt, C. S., Elizondo-Fraire, A. C., Liu, G., Lozano, G.
(2006). Synergistic roles of Mdm2 and Mdm4 for p53 inhibition in central nervous system development. Proc. Natl. Acad. Sci. USA
103: 3226-3231
[Abstract]
[Full Text]