- Chlamydia prevents mitochondrial fragmentation
Chlamydiae are intracellular pathogens that depend on the host for their survival and development. Chowdhury et al. demonstrate that Chlamydia trachomatis infection can prevent mitochondrial fission in primary cells by reducing DRP1 abundance via miR-30c–dependent inhibition of p53.
- New fluorescent sphingomyelin analogs
The behavior of sphingomyelin (SM) in the plasma membrane is unclear. Using new fluorescent SM analogs and single-molecule tracking, Kinoshita et al. find that SM transiently and continually interacts with the glycosylphosphatidylinositol (GPI)-anchored protein CD59 in oligomer size–, cholesterol-, and GPI anchoring–dependent manners.
- Role of PLEKHM1 in vesicle–lysosome fusion
Rab7 and Arl8b mediate vesicle transport and fusion with lysosomes. Marwaha et al. show that the Rab7 effector PLEKHM1 competes with PLEKHM2/SKIP for binding to Arl8b and that Arl8 mediates recruitment of the HOPS complex to PLEKHM1-positive vesicles for fusion, suggesting that Arl8b and its effectors orchestrate lysosomal transport and fusion.
- Membrane remodeling in embryonic abscission
König et al. perform time-resolved electron tomographic reconstructions to decipher the membrane remodeling events in abscission, the final step of cytokinesis, in Caenorhabditis elegans and find that completion of the scission process requires actomyosin-driven membrane remodeling, but not the ESCRT machinery.
- Structure of the RZZ complex
The Rod–Zw10–Zwilch (RZZ) complex assembles as a fibrous corona on kinetochores before microtubule attachment during mitotic spindle formation. Mosalaganti et al. provide new structural insight into the Spindly–RZZ complex that suggests that it resembles a dynein adaptor–cargo pair in the kinetochore corona.
- Dynein recruitment to kinetochores
The dynein motor is recruited to the kinetochore to capture spindle microtubules and control the spindle assembly checkpoint. Gama et al. reveal the molecular mechanism of how the Rod–Zw10–Zwilch complex and Spindly mediate dynein recruitment in Caenorhabditis elegans and human cells.
- Role of INCENP domains in chromosome biorientation
The chromosomal passenger complex (CPC), which includes the Aurora B kinase and the scaffold Sli15/INCENP, promotes chromosome biorientation. Fink et al. engineer a minimal CPC construct made of Aurora B and Sli15/INCENP and determine how specific protein domains contribute to chromosome biorientation.