Rasd1 modulates the coactivator function of NonO in the cyclic AMP pathway

• Published in: PloS one 2011-09, Vol.6 (9), p.e24401-e24401
• Main Authors: Ong, Shufen Angeline, Tan, Jen Jen, Tew, Wai Loon, Chen, Ken-Shiung
• Format: Article
• Language: English
• Subjects: Activation; Animals; Biology; Cell Line; Chlorocebus aethiops; Chromatin; Chromatin Immunoprecipitation; Circadian rhythm; Circadian rhythms; COS Cells; Cyclic adenosine monophosphate; Cyclic AMP; Cyclic AMP - metabolism; Entrainment; Fluorescent Antibody Technique, Indirect; G proteins; Genetic research; GTP; Guanosine triphosphate; Hormones; Humans; Hydrolysis; Immunofluorescence; Immunoprecipitation; Kinases; MAP kinase; Mass Spectrometry; Medicine; Mice; Nuclear Matrix-Associated Proteins - genetics; Nuclear Matrix-Associated Proteins - metabolism; Octamer Transcription Factors - genetics; Octamer Transcription Factors - metabolism; PC12 Cells; Physiological aspects; Protein Binding; Protein kinase; Protein kinases; ras Proteins - genetics; ras Proteins - metabolism; Rats; Reporter gene; Rhythm; RNA-Binding Proteins - genetics; RNA-Binding Proteins - metabolism; Rodents; Signal Transduction - genetics; Signal Transduction - physiology; Signaling; Transcription activation
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0024401

All living organisms exhibit autonomous daily physiological and behavioural rhythms to help them synchronize with the environment. Entrainment of circadian rhythm is achieved via activation of cyclic AMP (cAMP) and mitogen-activated protein kinase signaling pathways. NonO (p54nrb) is a multifunctional protein involved in transcriptional activation of the cAMP pathway and is involved in circadian rhythm control. Rasd1 is a monomeric G protein implicated to play a pivotal role in potentiating both photic and nonphotic responses of the circadian rhythm. In this study, we have identified and validated NonO as an interacting partner of Rasd1 via affinity pulldown, co-immunoprecipitation and indirect immunofluorescence studies. The GTP-hydrolysis activity of Rasd1 is required for the functional interaction. Functional interaction of Rasd1-NonO in the cAMP pathway was investigated via reporter gene assays, chromatin immunoprecipitation and gene knockdown. We showed that Rasd1 and NonO interact at the CRE-site of specific target genes. These findings reveal a novel mechanism by which the coregulator activity of NonO can be modulated.