- KDM3A regulation of actin affects IFT
Yeyati et al. demonstrate that the histone demethylase KDM3A acts as a negative regulator of ciliogenesis by modulating actin dynamics, both transcriptionally and by directly binding actin. KDM3A influences local actin networks to restrict intraflagellar transport during ciliogenesis; in its absence, cilia become unstable with abnormal lengths and accumulated intraflagellar transport proteins.
- Differential role of actin isoforms in motoneurons
α-, β-, and γ-actin differentially regulate cytoskeletal dynamics and stability in axons of motoneurons. Locally translated α-actin contributes to stable actin filaments in axonal branches, whereas β- and γ-actin give rise to highly dynamic filaments that modulate growth cone dynamics.
- TorsinA-dependent rearward nuclear movement
In fibroblasts and myoblasts polarizing for migration, retrograde actin flow moves the nucleus rearward, orienting the centrosome toward the leading edge. The nucleus engages moving dorsal actin cables through linear arrays of nesprin-2G and SUN2 called TAN lines. In this study, Saunders et al. report that the nuclear envelope–localized AAA+ ATPase torsinA and its activator, LAP1, are required for TAN line assembly and retrograde dorsal actin cable flow.
- Mtb replicates within necrotic human macrophages
Mycobacterium tuberculosis triggers macrophage cell death by necrosis, but it is unclear how this affects bacterial replication. Lerner et al. show that this pathogen replicates within necrotic human macrophages before disseminating to other cells upon loss of plasma membrane integrity.
- CENP-A is a homotypic octameric nucleosome
In this study, the authors use new reference models for 23 human centromeres and find that at all cell cycle phases centromeric CENP-A chromatin complexes are octameric nucleosomes with two molecules of CENP-A. This finding refutes previous models that have suggested that hemisomes may briefly transition to octameric nucleosomes.
- VHL–NF-κB regulate VCAM-1 in ccRCC cells
Labrousse-Arias et al. show that VHL expression leads to increased VCAM-1 levels in renal cell carcinoma through an NF-κB–dependent mechanism that seems to contribute to the antitumoral immune response. This study also suggests that VCAM-1 levels might serve as a marker of ccRCC progression in human patients.
- Competitive control of end resection by TOPBP1
Shimada and Gasser discuss new findings from the Smolka laboratory supporting a competitive model for nonhomologous end joining and homologous recombination factors at DNA breaks.
- A conserved role for TOPBP1Dpb11 in DNA repair
The scaffold protein TOPBP1Dpb11 has been implicated in homologous recombination DNA repair, but its function and mechanism of action remain unclear. Liu et al. define a conserved role for TOPBP1Dpb11 in recombination control through regulated, opposing interactions with pro- and anti-resection factors.