Protein B23 is a nucleolar and nuclear matrix-associated phosphoprotein that is involved in ribosome synthesis. Its expression and phosphorylation in rat ventral prostate, an androgen target organ, are profoundly influenced by androgens. Induction of programmed cell death (apoptosis) in the prostatic epithelium by androgen deprivation in the animal induces an early decline in protein B23 in the absence of a corresponding loss of protein B23 mRNA. We have now demonstrated that prostatic nuclei retain the ability to transcribe the B23 mRNA and that a significant amount of this mRNA persists even after 7 days of androgen deprivation when >80% of the prostatic epithelial cells have undergone apoptosis. The B23 mRNA from these nuclei is also translatable in vitro. However, the majority of the B23 mRNA is associated with free and short-stretch polysomes, which may account for the castration-induced decline in synthesis of protein B23 in vivo. In addition, the mechanism of down-regulation of protein B23 in apoptotic prostatic cells appears to relate to two coordinate signals, which include loss of phosphorylation of the protein as well as the expression of a protease active toward dephosphorylated protein B23, under these conditions.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				J. Pallares, D. Llobet, M. Santacana, N. Eritja, A. Velasco, D. Cuevas, S. Lopez, V. Palomar-Asenjo, A. Yeramian, X. Dolcet, et al. CK2{beta} Is Expressed in Endometrial Carcinoma and Has a Role in Apoptosis Resistance and Cell Proliferation Am. J. Pathol., January 1, 2009; 174(1): 287 - 296. [Abstract] [Full Text] [PDF]

				A. Melnick and J. D. Licht Deconstructing a Disease: RAR{alpha}, Its Fusion Partners, and Their Roles in the Pathogenesis of Acute Promyelocytic Leukemia Blood, May 15, 1999; 93(10): 3167 - 3215. [Full Text] [PDF]

				Y. Wang, W. Guo, L. Liang, and W. J. Esselman Phosphorylation of CD45 by Casein Kinase 2. MODULATION OF ACTIVITY AND MUTATIONAL ANALYSIS J. Biol. Chem., March 12, 1999; 274(11): 7454 - 7461. [Abstract] [Full Text] [PDF]

				C. Guo, S. Yu, A. T. Davis, and K. Ahmed Nuclear Matrix Targeting of the Protein Kinase CK2 Signal as a Common Downstream Response to Androgen or Growth Factor Stimulation of Prostate Cancer Cells Cancer Res., March 1, 1999; 59(5): 1146 - 1151. [Abstract] [Full Text] [PDF]

				C. Guo, A. T. Davis, and K. Ahmed Dynamics of Protein Kinase CK2 Association with Nucleosomes in Relation to Transcriptional Activity J. Biol. Chem., May 29, 1998; 273(22): 13675 - 13680. [Abstract] [Full Text] [PDF]

				C. Guo, S. Yu, A. T. Davis, H. Wang, J. E. Green, and K. Ahmed A Potential Role of Nuclear Matrix-associated Protein Kinase CK2 in Protection against Drug-induced Apoptosis in Cancer Cells J. Biol. Chem., February 16, 2001; 276(8): 5992 - 5999. [Abstract] [Full Text] [PDF]