In today’s new edition of JCB, Ducuing et al. identify a feed-forward signaling loop that allows Drosophila embryos to complete the process of dorsal closure. As explained in this week’s In Focus, the loop, which involves the signaling proteins JNK and DPP, helps embryos complete morphogenesis in the face of environmental and genetic challenges.
Otomo et al. demonstrate that B cells need the protein-sorting signal mannose 6-phosphate to proliferate, differentiate, and present antigens. As described here, in the absence of mannose 6-phosphate synthesis – a feature of the human disease mucolipidosis II – B cells can’t target proteases to lysosomes to process and present antigens, which therefore inhibits the cells’ ability to mature and produce antibodies.
LeClaire et al. identify a kinase that helps activate the actin-nucleating Arp2/3 complex. Nck-interacting kinase, or NIK, phosphorylates Arp2 and induces actin polymerization and membrane protrusion in response to epidermal growth factor. More here.
Shibuya et al. identify a protein complex that helps return wandering proteins back to the ER. As summarized here, the authors identify a protein complex consisting of the Golgi proteins Erv41 and Erv46, which binds to escaped ER proteins and returns them home in COPI vesicles.
And Craft et al. reveal that the intraflagellar transport of tubulin is specifically upregulated in regenerating cilia so that large amounts of the protein can be delivered to the growing ends of the organelles’ microtubules. Senior author Karl Lechtreck describes his group’s findings in this month’s biosights video, which you can watch below or subscribe to in iTunes. And if you’d like to discuss the implications of this study with your colleagues, don’t forget you can download everything you could possibly need for a Journal Club presentation here.
Cover image showing lysosomal storage material accumulating in mannose 6-phosphate-deficient B cells © 2015 Otomo et al.