Actin and myosin I in the nucleus: what next?

Several recent publications have demonstrated the importance of nuclear actin and nuclear myosin I in transcription. Here we review these publications and their implications. In addition, we discuss some important issues that should be addressed to gain a more comprehensive understanding of how these traditionally 'cytoplasmic' proteins are involved in transcription. We propose highly speculative models and mechanisms solely to stimulate thought and experimentation in this area.