Robust microtubule dynamics facilitate low-tension kinetochore detachment in metaphase
During mitosis, duplicated chromosomes are segregated to daughter cells. The cell detaches improperly attached chromosomes from their associated microtubules to prevent errors in chromosome segregation. In this work, it is found that the mechanical forces produced via the dynamic growth and shortening of microtubules act to efficiently facilitate these detachment events.
The Ndc80-Cdt1-Ska1 complex is a central processive kinetochore–microtubule coupling unit
The mechanism of how mitotic kinetochores accomplish robust, long-distance coupling with spindle microtubule plus-ends during metaphase and anaphase is unknown. This work demonstrates that the replication licensing protein Cdt1 synergizes with kinetochore Ndc80 and the Ska1 complexes to form a tripartite Ndc80-Cdt1-Ska1 complex that processively tracks the plus-ends of dynamic microtubules.
Design principles for selective polarization of PAR proteins by cortical flows
Illukkumbura et al. reveal that cluster-dependent tuning of membrane binding rather than size-dependent coupling to the actomyosin cortex enables differential transport of PAR proteins by cortical flows in the C. elegans zygote.
Centralspindlin proteins Pavarotti and Tumbleweed along with WASH regulate nuclear envelope budding
Nuclear envelope (NE) budding is a nuclear export pathway for large macromolecular machineries. Davidson et al. show that the Centralspindlin proteins Pav and Tum work in two different nuclear WASH complexes to regulate the physical machineries of NE budding.
A selectivity filter in the ER membrane protein complex limits protein misinsertion at the ER
Pleiner, Hazu, Pinton Tomaleri et al. identify a selectivity filter in the ER membrane protein complex (EMC) and show that the EMC protects the integrity of the ER proteome by limiting the misinsertion of mitochondrial tail-anchored proteins and enforcing the correct topology of multipass membrane proteins.
Reticular adhesions are assembled at flat clathrin lattices and opposed by active integrin α5β1
Hakanpää et al. show that reticular adhesions are assembled at flat clathrin lattices, a process inhibited by fibronectin and its receptor, integrin α5β1. This novel adhesion assembly mechanism is coupled to cell migration and reveals a unique crosstalk between cell-matrix adhesions.
Small lipid droplets are rigid enough to indent a nucleus, dilute the lamina, and cause rupture
Ivanovska and Tobin plus coworkers show that fat-filled lipid droplets have a high interfacial tension which helps to maintain the sphericity of small droplets—even when interacting with the cytoskeleton and nucleus that can be deformed and sometimes disrupted by small droplets.
Triggered Golgi membrane enrichment promotes PtdIns(4,5)P2 generation for plasma membrane repair
Meng et al. report that upon plasma membrane damage in a cell, the Golgi apparatus accumulates at the wound site and facilitates membrane repair by converting PtdIns4P to PtdIns(4,5)P2 in C. elegans. This finding advances our understanding of cellular survival mechanisms under mechanical stress.