MacTaggart et al. identify an ATE1-dependent arginylation site at E77 of α-tubulin and show that this modification regulates the binding of MAP1S to microtubules. Deletion of Ate1 or overexpression of non-arginylatable α-tubulin results in increased MAP1S binding and reduced microtubule dynamics.

Iyer et al. combine in vitro reconstitution assays with cryo-electron tomography, biophysical, and cell biological approaches to show that two centriolar proteins, CP110 and CPAP, exhibit antagonistic activities at microtubule plus ends. Together, they impart very slow but processive microtubule polymerization, and their interaction promotes robust centriole formation.

In the early Drosophila embryo, germband extension requires positional switches of neighboring epithelial cells through remodeling of cell–cell junctions. Linvill et al. find that junctions systematically rotate from a horizontal towards a vertical orientation. During this process, rotating interfaces acquire myosin and newly initialized contractile identities, which allows for multiple rounds of intercalation.

Liang et al. elucidate that TPX2 possesses α-helical repeats exhibiting opposite preferences for “extended” and “compacted” tubulin dimer spacing, with the C-terminal repeat group R8-9 being crucial for its function. They also highlight the synergy between TPX2 and HURP in stabilizing spindle microtubules.

LRRK2 is a kinase whose activity is linked to Parkinson’s disease. This study identifies a pathway that links LRRK2 activation to lysosome perturbations. This pathway involves the process known as CASM and culminates in an interaction between LRRK2 and GABARAP at the surface of lysosomes.

The accumulation of defective polypeptides is a significant cause of various diseases. The authors developed a probe that is specific for defective proteins, which allowed the isolation and visualization of as-yet-hypothetical existence of endogenous orphaned polypeptides as tangible entities.

This paper shows how epithelial cell–cell junctions play a critical role in the fidelity of cell division, where persistent unfolding of the mechanosensitive cadherin complex and actin-binding component, alpha catenin, interferes with cytokinesis through excessive sequestration of the abscission factor, LZTS2.