Characterizing the Functional Importance of Actin Dynamics in the Nucleus

Cytoskeletal actin is a well-established regulator of cell shape and movement. Actin is also actively imported into the nucleus, where it is directly implicated in transcriptional regulation. Yet, how nuclear actin functions is unclear. Unlike cytoskeletal actin, which polymerizes into filaments, there are no visible actin filaments in the nucleus. More so, controversy still surrounds the polymerization state and dynamics of nuclear actin. Here, we explore the functional role of actin in the nucleus and the effects of changing nuclear actin’s polymerization state. Specifically, we investigate how disrupting nuclear actin dynamics by forming nuclear actin filaments impacts transcription, nuclear organization, chromatin remodeling and class I HDAC activity, as well as the contribution of nuclear actin polymerization to the pathogenesis of intranuclear rod myopathy, cellular stress, and adenovirus infection.