Opinion in 2016

The establishment of various coexisting actin networks supports a plethora of cellular processes and functions. How actin incorporation into these different networks is regulated to balance their growth and maintain homeostasis has remained elusive. Here, the authors propose that the internetwork competition for a limited pool of actin monomers underlies the homeostatic control of actin cytoskeleton organization.

Many proteins that canonically function in the cytosol can also localize to the nucleus. The authors propose that a distinct group of such proteins (which they name STRaNDs) engage in a particular mode of signal transduction, whereby in response to extracellular cues, the cytosolic protein transits to the nucleus and regulates gene expression without direct DNA binding.

Quante and Bird propose that the epigenome is modulated by the recruitment of cell type-specific DNA-binding proteins to short, abundant sequence motifs. The regulation of gene expression may thus be simplified by tuning gene expression in multigene blocks.

Members of the major facilitator superfamily are highly conserved transmembrane proteins that transport various small molecules, including nutrients, drugs, signalling molecules and waste products, across the plasma membrane. A novel model of their functional cycle provides insights into how these important transporters operate on the molecular level.