Proliferating cell nuclear antigen is required for loading of the SMCX/KMD5C histone demethylase onto chromatin

• Main Authors: Liang Zhihui, Diamond Marc, Smith Johanna A, Schnell Matthias, Daniel René
• Format: Article
• Language: English
• Published: BMC 2011-10-01
• Series: Epigenetics & Chromatin
• Online Access: http://www.epigeneticsandchromatin.com/content/4/1/18

<p>Abstract</p> <p>Background</p> <p>Histone methylation is regulated by a large number of histone methyltransferases and demethylases. The recently discovered SMCX/KMD5C demethylase has been shown to remove methyl residues from lysine 4 of histone H3 (H3K4), and constitutes an important component of the regulatory element-1-silencing transcription factor (REST) protein complex. However, little is known about the cellular mechanisms that control SMCX activity and intracellular trafficking.</p> <p>Results</p> <p>In this study, we found that small interfering RNA-mediated knockdown of proliferating cell nuclear antigen (PCNA) resulted in the reduction of the chromatin-bound SMCX fraction. We identified a PCNA-interaction protein motif (PIP box) in the SMCX protein. Using site-directed mutagenesis, we found that the amino acids of the SMCX PIP box are involved in the association of SMCX with PCNA and its interaction with chromatin.</p> <p>Conclusions</p> <p>Our data indicate that the intracellular trafficking of SMCX is controlled by its association with PCNA.</p>