The Editorial Board of Molecular Biology of the Cell has highlighted the following articles from the October 2016 issues. From among the many fine articles in the journal, the Board selects for these Highlights articles that are of broad interest and significantly advance knowledge or provide new concepts or approaches that extend our understanding.
Shown are parts of an ovariole, including stages 5–9 of follicle development (top, scale bar = 50 microns), from a wild-type Drosophila melanogaster specimen and enlarged images of stages 5, 6, and 7/8 (bottom, scale bars = 10 microns). Nuclear actin was labeled with anti-actin C4 (green) and the nuclear envelope was labeled with wheat germ agglutinin (magenta). The images show that during stages 5–9 of follicle development the nurse cells accumulate varying levels of structured nuclear actin and high levels of nuclear actin are observed in the oocyte nucleus. Somatic follicle cells also exhibit nuclear actin during stages 5–6. The stage-specific accumulation of nuclear actin suggests that it plays a role during this period of oogenesis. See the article by Kelpsch et al. (Mol. Biol. Cell 27, 2965–2979). (Image: Tina Tootle, Department of Anatomy and Cell Biology, University of Iowa Carver College of Medicine)
Role of BMP receptor traffic in synaptic growth defects in an ALS model
Mugdha Deshpande, Zachary Feiger, Amanda K. Shilton, Christina C. Luo, Ethan Silverman, and Avital A. Rodal
In a Drosophila model of ALS, neuronal defects are associated with altered endosomal traffic of growth factor receptors and loss of growth-promoting signals. Manipulation of an endosomal recycling pathway suppresses these neuronal defects. The findings suggest that rerouting membrane traffic could be therapeutic in ALS.
Mol. Biol. Cell 27 (19), 2898–2910
C9orf72 binds SMCR8, localizes to lysosomes, and regulates mTORC1 signaling
Joseph Amick, Agnes Roczniak-Ferguson, and Shawn M. Ferguson
C9orf72 interacts strongly with SMCR8 and depends on this interaction for its stability. Lysosomes are major sites of C9orf72 subcellular localization, and abnormal lysosome morphology is seen in its absence. Defects are found in the regulation of the lysosome-localized mTORC1 signaling pathway in C9orf72 KO cells.
Mol. Biol. Cell 27 (20), 3040–3051
The spatial and temporal control of microtubule dynamics is fundamentally important for proper spindle assembly and chromosome segregation. This is achieved, in part, by the multitude of proteins that bind to and regulate spindle microtubules, including kinesin superfamily members. Kif18B is a member of the kinesin-8 family that is enriched on the plus-ends of astral microtubules. In this image showing a PtK2 cell in which Kif18B was knocked down, the long astral microtubules (green) appear rigid and extend across the cell where they appear to interact with the actin cytoskeleton (red). Knockdown of Kif18B also causes defects in chromosome (blue) alignment. See the article by Walczak et al. (Mol. Biol. Cell 27, 3021–3030). (Image: Sachin Jain, Indiana University)