Szikora et al. use superresolution microscopy to reveal muscle protein localizations at the nanoscale level. With this protein localization atlas and template-based protein structure modeling, they assemble refined I-band and H-zone models and provide new mechanistic insights into sarcomerogenesis.

Maniscalco et al. show that primordial germ cells remodel by assembling a nonmitotic contractile ring. Ring formation requires the RhoGEF ECT-2 and its activator NOP-1 but not centralspindlin, which activates ECT-2 to position the cytokinetic contractile ring during mitosis.

Talin and vinculin control mechanosensing by linking adhesion receptors to the contractile actin cytoskeleton. Using a mitochondrial targeting system, Atherton et al. elucidate mechanisms regulating conformational changes required for vinculin binding to talin. Such activation mechanisms are not required for either protein to interact with the adhesion regulatory protein paxillin.

Girão et al. use structure-guided functional mutants of CLASP2 to show that recognition of growing microtubule plus-ends through EB–protein interaction and the ability to associate with curved microtubule protofilaments through TOG2 and TOG3 domains promote growth and stabilization of kinetochore–microtubules required for poleward flux.

Many active genes position near nuclear speckles. Kim et al. show that Hsp70 speckle association correlates with increased nascent transcripts. Live-cell imaging shows that increases in nascent Hsp70 transcripts strictly follow speckle association (∼0–2 min), suggesting that speckle association amplifies gene expression.

Derrer et al. show that the mRNA export factor Mex67 can perform its essential function when stably tethered to the nuclear pore complex.

Soh et al. study the organization of Tetrahymena ciliary arrays. Basal body–associated striated fibers organize motile cilia by promoting basal body orientation, reorientation, and resistance to ciliary forces. To do so, striated fiber length is modulated to ensure connections between neighboring basal bodies and to the cell cortex.