Yesterday we took some time to remember Alan Hall, and focused on the tributes that appear in the latest edition of JCB. Today, we’ll take a quick look at some of the research highlights published in the same issue.
Wilmes et al. investigate why different type I interferons can trigger different cellular responses, despite binding to the same dimeric cell surface receptor. As discussed in this week’s In Focus, the researchers find that interferon ligands induce dimerization of the receptor subunits IFNAR1 and IFNAR2. The feedback regulator USP18 inhibits receptor dimerization such that only interferons with a relatively high affinity for IFNAR1 can recruit this subunit into the receptor complex and maintain signaling over longer time periods. These interferons can therefore induce different cellular responses than interferons with lower affinity for IFNAR1, which are quickly deactivated by USP18.
Murley et al. identify a yeast protein that might coordinate the function of vacuoles and mitochondria by transferring sterols at the sites where these organelles are contacted by the ER. As described here, the protein, which the researchers name Ltc1, localizes to ER-mitochondria and ER-vacuole contacts, and promotes both mitochondrial function and the stress-induced formation of sterol-rich domains in the vacuole membrane.
Luo et al. describe how the Drosophila ovarian niche limits its own ability to maintain germline stem cells in an undifferentiated state. Wnt signaling within the niche induces expression of the Dpp receptor Tkv, which mops up excess Dpp so that some of the stem cells’ progeny can undergo differentiation. More here.
Smith et al. describe a microscopy technique that instantaneously captures 3D images of live cells, allowing them to track the movement of single mRNAs in the nucleus. As described here, the technique, known as 3D-SMRT, enabled the researchers to image the entire volume of the nucleus 10 times per second, fast enough to track the diffusion of individual β-actin transcripts.
And two papers describe a surprising new role for the mitotic checkpoint proteins BUB1 and BUB3. Kim et al. and Yang et al., working in C. elegans and budding yeast, respectively, show that these proteins, best known for their role in inhibiting anaphase onset if kinetochores aren’t properly attached to the mitotic spindle, also function to promote anaphase onset. You can hear the senior authors of these two studies, Arshad Desai and Soni Lacefield, discuss their findings in this month’s biobytes podcast, where you can also listen to Talila Volk describe her lab’s characterization of a myonuclear scaffold that maintains the shape of muscles in Drosophila larval muscles. You can listen below or subscribe in iTunes.
That’s all for today, but, as always, there are plenty of other interesting articles for you to discover by visiting our table of contents here.
Cover image showing the expression of Tkv (red) in a wild-type Drosophila germarium © 2015 Luo et al.