HDAC1, HDAC4, and HDAC9 Bind to PC3/Tis21/Btg2 and Are Required for Its Inhibition of Cell Cycle Progression and Cyclin D1 Expression

• Published in: Journal of cellular physiology 2017-07, Vol.232 (7), p.1696-1707
• Main Authors: Micheli, Laura, D'Andrea, Giorgio, Leonardi, Luca, Tirone, Felice
• Format: Article
• Language: English
• Subjects: Animals; Catalytic Domain; Cell Cycle; Cell Proliferation; Cyclin D1 - metabolism; Gene Silencing; HEK293 Cells; Histone Deacetylases - chemistry; Histone Deacetylases - metabolism; Humans; Immediate-Early Proteins - metabolism; Immunoprecipitation; Mice; NIH 3T3 Cells; Protein Binding; Rats; Transcription, Genetic; Tumor Suppressor Proteins - metabolism
• ISSN: 0021-9541; 1097-4652
• DOI: 10.1002/jcp.25467

PC3/Tis21 is a transcriptional cofactor that inhibits proliferation in several cell types, including neural progenitors. Here, we report that PC3/Tis21 associates with HDAC1, HDAC4, and HDAC9 in vivo, in fibroblast cells. Furthermore, when HDAC1, HDAC4, or HDAC9 are silenced in fibroblasts or in a line of cerebellar progenitor cells, the ability of PC3/Tis21 to inhibit proliferation is significantly reduced. Overexpression of HDAC1, HDAC4, or HDAC9 in fibroblasts and in cerebellar precursor cells synergizes with PC3/Tis21 in inhibiting the expression of cyclin D1, a cyclin selectively inhibited by PC3/Tis21. Conversely, the depletion of HDAC1 or HDAC4 (but not HDAC9) in fibroblasts and in cerebellar precursor cells significantly impairs the ability of PC3/Tis21 to inhibit cyclin D1 expression. An analysis of HDAC4 deletion mutants shows that both the amino‐terminal moiety and the catalytic domain of HDAC4 associate to PC3/Tis21, but neither alone is sufficient to potentiate the inhibition of cyclin D1 by PC3/Tis21. As a whole, our findings indicate that PC3/Tis21 inhibits cell proliferation in a way dependent on the presence of HDACs, in fibroblasts as well as in neural cells. Considering that several reports have demonstrated that HDACs can act as transcriptional corepressors on the cyclin D1 promoter, our data suggest that the association of PC3/Tis21 to HDACs is functional to recruit them to target genes, such as cyclin D1, for repression of their expression. J. Cell. Physiol. 232: 1696–1707, 2017. © 2016 Wiley Periodicals, Inc. By silencing HDAC1, HDAC4, and HDAC9 in fibroblast as well as in neural cells, we reveal that HDAC1, HDAC4, and HDAC9 are each required for the negative control of the cell cycle exerted by PC3/Tis21. Such effect is likely dependent on the ability of HDAC1, HDAC4, and HDAC9 to associate with PC3/Tis21, that we demonstrate here. Moreover, we find that HDAC1 and HDAC4—but not HDAC9—are required for the inhibition exerted by PC3/Tis21 of cyclin D1 expression.