February 2013 | Volume 200, No. 4
In This Issue
People & Ideas
- Microtubule-organizing center formation at telomeres induces meiotic telomere clustering
Telomere-localized SUN and KASH proteins induce formation of a microtubule-based “telocentrosome” that fosters microtubule motor-dependent telomere clustering.
- SecYEG activates GTPases to drive the completion of cotranslational protein targeting
SecYEG drives conformational changes in the cotranslational targeting complex to activate it for GTP hydrolysis and the handover of the translating ribosome.
- Robust polarity establishment occurs via an endocytosis-based cortical corralling mechanism
Cell polarity can be established via the spatial coordination of the opposing membrane trafficking activities of endocytosis and exocytosis.
- Clathrin and AP2 are required for PtdIns(4,5)P2-mediated formation of LRP6 signalosomes
PtdIns(4,5)P2 promotes the assembly of LRP6 signalosomes at the cell surface via the recruitment of AP2 and clathrin.
- Condensin II initiates sister chromatid resolution during S phase
Condensin II initiates structural reorganization of duplicated chromosomes during S phase to prepare for their proper condensation and segregation in mitosis.
- Rbfox3-regulated alternative splicing of Numb promotes neuronal differentiation during development
Rbfox3 is required to promote neuronal differentiation of postmitotic neurons through Numb alternative splicing.
- Conserved and divergent features of kinetochores and spindle microtubule ends from five species
A comprehensive, cross-species electron tomography analysis of kinetochore–microtubule interfaces has provided insight into shared structural features and their likely functional consequences.
- Rag GTPases mediate amino acid–dependent recruitment of TFEB and MITF to lysosomes
Active Rag GTPases are required for recruitment of TFEB to lysosomes and its phosphorylation by mTORC1, inhibiting its function under nutrient-rich conditions.
- Grb2 controls phosphorylation of FGFR2 by inhibiting receptor kinase and Shp2 phosphatase activity
Grb2 inhibits the kinase activity of FGFR2 and the phosphatase activity of Shp2 to maintain homeostasis of receptor phosphorylation in the nonstimulated state.
- The microtubule affinity regulating kinase MARK4 promotes axoneme extension during early ciliogenesis
A functional screen identified MARK4 as a positive regulator of axonemal extension and ciliogenesis via its interaction with the mother centriolar protein ODF2.
- Obscurin is required for ankyrinB-dependent dystrophin localization and sarcolemma integrity
Obscurin contributes to the organization of subsarcolemma microtubules, localization of dystrophin at costameres, and maintenance of sarcolemmal integrity in skeletal muscle fibers.
- Canonical Wnt signaling inhibits osteoclastogenesis independent of osteoprotegerin
Canonical Wnt signaling through Fzd8 and β-catenin negatively regulates osteoclast differentiation and reduces bone resorption independent of osteoprotegerin.