Investigating the regulation of UHRF1 in cell cycle

Abstract

UHRF1 is a multi-domain protein with multiple functions in mammalian cells including maintenance of DNA methylation, histone modification, DNA damage et al. UHRF1 itself also undergoes various post-translational modifications such as ubiquitination and phosphorylation. However, little is known about its acetylation and the functional relevance.

Our lab has previously identified Mof as an acetyltransferase for UHRF1 in mammalian cells. Work by the lab mate further identified the specific acetylation sites of UHRF1. This project aims to examine the regulation of UHRF1 acetylation in cell cycle; and then to test whether the acetylation of UHRF1 plays a critical role in maintaining the stability of UHRF1. Results from this study confirmed the direct interaction between Mof and UHRF1. In addition the K667, K668, K670 are found responsible for UHRF1 acetylation. My work showed that the acetylation of UHRF1 peaks at G1 to S phase and continues to G1/M phase, which has the same tendency with UHRF1 expression during cell cycle. The UHRF1 stability becomes compromised when UHRF1-K667, -K668, -K670 were mutated to arginine (R), suggesting that these sites are responsible for acetylation of UHRF1, which is critical for protein stability.