BMAL1 shuttling controls transactivation and degradation of the CLOCK/BMAL1 heterodimer.

CLOCK and BMAL1 are bHLH-PAS-containing transcription factors that bind to E-box elements and are indispensable for expression of core circadian clock components such as the Per and Cry genes. A key step in expression is the heterodimerization of CLOCK and BMAL1 and their accumulation in the nucleus with an approximately 24-h periodicity. We show here that nucleocytoplasmic shuttling of BMAL1 is essential for transactivation and for degradation of the CLOCK/BMAL1 heterodimer.

Effects of Ser2 and Tyr6 mutants of BAF53 on cell growth and p53-dependent transcription.

BAF53 is an actin-related protein that shuttles between nucleus and cytoplasm. In the nucleus, it constitutes an integral component of many chromatin-modifying complexes such as the SWI/SNF, TIP60, TRRAP, and TIP48/49 complexes. BAF53 is essential for growth, but its function remains elusive.

Cytoplasmic localization and nucleo-cytoplasmic shuttling of BAF53, a component of chromatin-modifying complexes.

BAF53 (also known as ArpNbeta) is a nuclear arp that is a component of a number of chromatin-modifying complexes, such as the SWI/SNF and TRRAP complexes. These complexes play specific roles in chromatin remodeling and transcription. Previous studies have suggested that BAF53 is localized exclusively in the nucleus in HeLa and SW-13 cells.