Modifications of Activators

Many activators are subject to posttranslational modifications, such as phosphorylation (Brivanlou and Darnell, 2002), acetylation (Brooks and Gu, 2003), and glycosylation (Jackson and Tjian, 1988; Kamemura and Hart, 2003). In many cases the modifications can have positive roles in transcriptional activation. For example, phosphorylation of STAT is responsible for mediating the JAK/STAT signal transduction pathway (Brivanlou and Darnell, 2002; Darnell et al., 1994). Acetylation of p53 can increase its ability to bind DNA (Brooks and Gu, 2003; Gu and Roeder, 1997; Prives and Manley, 2001). Recent studies suggest that ubiquitination and SUMOylation also play important roles in regulating the activity of transcription factors. In several cases, the transcriptional activation functions of activators are dependent on ubiquitination. Due to space limitation, readers should refer to several recent review articles on this topic for further details (Conaway et al., 2002; Freiman and Tjian, 2003; Gill, 2004; Herrera and Triezenberg, 2004).

0 0

Post a comment