JCB

New issue: May 14th

In today’s new issue of JCB, Mitra et al. reveal how mitochondrial morphology regulates the development of Drosophila egg chambers. Egg chamber follicle cells lacking the mitochondrial fission protein Drp1 maintain a highly-fused mitochondrial network and hyperproliferate instead of exiting the cell cycle and terminally differentiating. Depleting the mitochondrial fusion protein Marf-1, on the other hand, causes follicle cells to differentiate prematurely. Senior author Jennifer Lippincott-Schwartz explains in this summary that mitochondrial morphology might be linked to differentiation because cells’ energetic requirements change when they exit the cell cycle. Meanwhile, Kageyama et al. demonstrate that mouse neurons lacking Drp1 die because their mitochondria fuse and accumulate oxidative damage.

Shevchuk et al. use ion conductance microscopy – a technique that rapidly scans the topography of the plasma membrane – to examine how clathrin-coated pits close as they internalize from the cell surface. (If you haven’t heard of ion conductance microscopy before, the authors provide a nice explanation at the start of their Materials and Methods section). Clathrin-coated pits are generally thought to seal off from a flat region of the plasma membrane, but Shevchuk et al. find that 70% of them are capped by a membrane protrusion that grows from one side of the pit. You can read about the differences between these two mechanisms of pit closure in this summary.

Wei et al. identify an miRNA family that inhibits the differentiation and proliferation of bone-forming osteoblasts. miR-34b and miR-34c decrease bone formation in mice by reducing levels of the osteoblast differentiation factor Satb2 and the cell cycle proteins Cyclin D1, CDK4, and CDK6. As explained in this week’s In Focus, though miRNAs have been implicated in bone formation before, this is the first in vivo study of how individual miRNAs regulate osteoblast differentiation.

Oikawa et al., on the other hand, study the differentiation of bone-resorbing osteoclasts. This process involves the fusion of precursor cells to form mature, multi-nucleate osteoclasts (such as the one pictured on this week’s cover, for example). Oikawa et al. reveal that osteoclast cell fusion is mediated by invasive, podosome-like protrusions that are formed by the phospholipid-binding adaptor protein Tks5. More here. 

There’s lot’s of other great papers that you can find on our table of contents, but I’ll leave you today with a link to this month’s biosights video podcast, in which Ryan Petrie describes a new way that fibroblasts migrate through three-dimensional environments.  As revealed in this paper, depending on the strength of intracellular RhoA signaling and on the elastic behavior of the extracellular matrix, fibroblasts can form blunt, cylindrical protrusions called lobopodia instead of thin, wide lamellipodia-like extensions.

If you work in a cell migration lab and would like to discuss Petrie et al.’s study with your colleagues, you can download a “Journal Club Pack” for the paper by clicking here.

Cover image courtesy of Tsukasa Oikawa.

 

New issue: April 30th

In today’s new issue of JCB, Inoko et al. reveal how proliferating cells ensure they don’t regrow a primary cilium until they return to quiescence. The centriolar protein trichoplein activates the Aurora A kinase to suppress ciliogenesis in cycling cells.  When cells exit the cell cycle, however, trichoplein is lost from the centriole that becomes the ciliary basal body, allowing ciliogenesis to proceed in quiescent cells. Knocking down trichoplein or Aurora A causes proliferating cells to aberrantly form primary cilia and arrest their cell cycle. As senior author Masaki Inagaki explains in this week’s In Focus, the results suggest that, unlike lower organisms, the vertebrate cell cycle may be regulated by primary cilia assembly and resorption.

Huang et al. describe how the anaphase promoting complex restricts apoptosis, and how this inhibition is relieved following DNA damage. The anaphase promoting complex is a multi-subunit ubiquitin ligase that promotes mitotic exit. Huang et al. find that the complex also targets the pro-apoptotic protein MOAP-1 for ubiquitination and proteasomal degradation. Following DNA damage, however, the anaphase promoting complex is inhibited by another ubiquitin ligase called Trim39, thereby stabilizing MOAP-1 levels and promoting cell death. You can read more about the pathway here.

Treusch and Lindquist reveal that the toxic yeast prion protein Rnq1 arrests cells in mitosis by inhibiting the duplication of spindle pole bodies, the yeast equivalent of centrosomes. Cytoplasmic aggregates of Rnq1 sequester the key spindle pole body component Spc42, indicating that misfolded proteins can cause toxicity through specific interactions with other proteins, rather than by generally inhibiting the cell’s protein folding and degradation machinery. You can read more in this summary.

And Dores et al. reveal how a G protein–coupled receptor (GPCR) can be transported to multivesicular bodies (MVBs) and lysosomes without being ubiquitinated. Most GPCRs are ubiquitinated and sorted into the intralumenal vesicles of MVBs by interacting with ubiquitin-binding ESCRT complexes. Dores et al. show that the thrombin receptor PAR1 follows the same route but is linked to the ESCRT-III complex via a ubiquitin-independent interaction with an accessory protein called ALIX. More here.

Elsewhere, there’s a fascinating paper by Petrie et al., who describe a new way in which fibroblasts migrate through 3D environments. When moving across a flat surface, fibroblasts form wide, flat membrane protrusions at their leading edge called lamellipodia. The cells form lamellipodia in some 3D matrices as well, but Petrie et al. show that, in certain environments, fibroblasts form a cyclindrical, blunt-shaped “lobopodium” at their leading edge instead. The researchers demonstrate that the switch between lobopodia and lamellipodia-based motility depends on RhoA signaling and on the elastic properties of the extracellular matrix. Michael Sixt summarizes Petrie et al.’s findings and the various modes of cell migration in this accompanying commentary.

Meanwhile, Rotty and Coulombe describe how the intermediate filament protein keratin 6 inhibits the tyrosine kinase Src to limit the migration of keratinocytes following wounding.

Finally for today, Pignatelli et al. reveal how the focal adhesion protein Hic-5 promotes the formation of invadopodia and cell invasion in response to TGFbeta. You can listen to senior author Christopher Turner describe his lab’s findings in this week’s biobytes podcast, where you can also hear Arthur de Jong discuss his recent study of how the strength of pre-synaptic terminals depends on where they contact the post-synaptic dendritic tree. You can listen below or subscribe in iTunes.

As always, you can find our full table of contents here - I’ll simply finish up by pointing you in the direction of this editorial, which discusses some recent changes we’ve made to the review process at JCB. Let us know what you think!

Cover image courtesy of Akihito Inoko.

New issue: April 16th

Time for a quick roundup of some of the highlights from the latest issue of JCB.

Kawai and Amano describe a new function for the well-known breast cancer susceptibility gene BRCA1. As described in this summary, the researchers show that BRCA1 increases the maturation of microRNAs, by interacting with both primary microRNA transcripts and the DROSHA processing complex. The absence of BRCA1 causes a reduction in the levels of several microRNAs that dwindle in cancer tissues, and which may therefore usually act to suppress tumorigenesis.

BRCA1 is best known for its role in DNA repair, being recruited to double strand breaks after ubiqutination of the surrounding chromatin by ubiquitin ligases like RNF168. Poulsen et al. reveal a surprising function for the related ligase RNF169 – it actually competes with BRCA1 and other repair proteins for binding to ubiquitinated chromatin, thereby favoring break repair by homologous recombination rather than by non-homologous end joining. More here.

Our cover image compares two fibroblasts with and without ARPC3, a key component of the Arp2/3 actin nucleation complex. Suraneni et al. reveal that fibroblasts fail to make lamellipodial membrane protrusions in the absence of the Arp2/3 complex, and, without lamellipodia, the cells fail to migrate in a straightline for long distances. You can read more in this week’s In Focus.

Staying with cell migration, Steinberg et al. describe how the sorting nexin SNX17 helps recycle integrin adhesion molecules back to the cell surface instead of sending them to the lysosome for degradation. Cells lacking SNX17 have decreased levels of the alpha5 and beta1 integrins, and therefore move faster than control cells. You can read more in this summary.

There’s lots of other interesting papers elsewhere in today’s new issue – you can find them all on our table of contents – but today also sees the release of our latest biosights video podcast, which highlights the recent paper from Welf et al. describing how PI3-kinase signaling helps migrating cells reorient themselves by stabilizing branched protrusions at the cell’s leading edge. Senior author Jason Haugh explains all in the video here and, if you'd like to present this paper to your colleagues in a journal club, you can download everything you need - including a pdf of the paper and a PowerPoint file of all the figures - by clicking here to download our monthly Journal Club Pack.

Cover image courtesy of Parveen Suraneni.

 

New issue: April 2nd

In today’s new issue of JCB, Burkart et al. explain how a secreted protease helps egg cells avoid being fertilized by more than one sperm. Initial fertilization leads to the exocytosis of cortical granules containing the protease ovastacin, which cleaves ZP2, a component of the egg’s outer layer, the zona pellucida. ZP2 cleavage prevents additional sperm from binding to the oocyte, ensuring that the fertilized egg can undergo normal embryonic development. You can read more in this summary.

Rullo et al. describe how actin polymerization helps leukocytes stay attached to blood vessel walls instead of being swept away by the flow of blood. The force of fluid flow stimulates leukocytes to form actin-rich structures (that the researchers term anchors), which reinforce the cells’ integrin-based adhesions to the underlying surface. (You can see a great example of a leukocyte anchor in the scanning electron micrograph on this week’s cover). Anchor formation depends on a signaling pathway involving PI-3-kinase and the small GTPases Rap1 and Rac. More here.

Anastasia et al. reveal that mitotic entry is linked to membrane transport, potentially explaining how cells coordinate growth and division. The researchers uncover a signaling pathway that leads from the GTPase Rho1 to the checkpoint proteins Wee1 and Cdc25, which prevents budding yeast from entering mitosis when vesicle transport to the plasma membrane is inhibited. Senior author Doug Kellogg explains in this week’s In Focus how the pathway might let cells know when they’ve grown big enough to divide in two.

Erlemann et al. use quantitative fluorescence microscopy to count how many gamma-tubulin small complexes (gamma-TuSCs) nucleate microtubules at budding yeast spindle bodies. The answer – summarized here – is 7 gamma-TuSCs (each containing two gamma-tubulin subunits) plus a few additional gamma-tubulin and Spc98 molecules. Senior author Elmar Schiebel also provides a review of centrosome biology in this issue, discussing recent developments in our understanding of the centrosome duplication cycle.

Meanwhile, Stavoe and Colon-Ramos describe how a Netrin signaling pathway (best known for its role in axonal guidance) also controls synapse formation by clustering synaptic vesicles at pre-synaptic terminals. Senior author Daniel Colon-Ramos discusses why and how this pathway multitasks in this week’s biobytes podcast, where you can also hear Chris Kaiser explain his lab’s recent work (Kim et al.) on the regulation of a key enzyme involved in protein folding in the ER. You can listen below or subscribe in iTunes.

Lots of other interesting papers in this week’s issue as well. You can find them all listed on our table of contents by clicking here…

Cover image courtesy of Jacob Rullo and Henry Hong.

New issue: March 19th

In today's new issue of JCB, Sarkar and Zohn reveal that the ubiquitin ligase Hectd1 restricts the migration of cranial mesenchyme cells by inhibiting secretion of the protein chaperone Hsp90. Excess extracellular Hsp90 enhances the motility of Hectd1-deficient cells, potentially explaining why Hectd1-mutant mouse embryos have an abnormally organized cranial mesenchyme and neural tube closure defects. You can read more in this week's In Focus.

Byrd et al. describe how a microRNA fine-tunes a cell's response to ER stress. The researchers identify a microRNA called miR-30C-2*, which is upregulated when ER function is compromised and which targets the mRNA encoding XBP1, a key transcription factor that boosts ER capacity and cell survival. Blocking miR-30C-2* leads to increased XBP1 levels and enhanced cell survival in response to ER stress. More here.

And Roux et al. report a new way to screen for protein-protein interactions. Proximity-dependent biotin identification, or BioID, involves tagging proteins of interest with a promiscuous bacterial biotin ligase. When the resulting fusion protein is expressed in mammalian cells, nearby proteins are biotinylated, allowing them to be purified and identified by mass spectrometry. Roux et al. tested their approach with the nuclear lamina protein Lamin-A and identified both known Lamin-A interacting proteins and a novel nuclear envelope protein called SLAP75. Senior author Kyle Roux explains some of the advantages of this new approach here.

Today also sees the release of our latest biosights video podcast, in which Johan de Rooij discusses his lab's recent paper (Huveneers et al.) describing how the remodeling of endothelial intercellular adhesions takes place at a specialized subset of adhesions called focal adherens junctions. These adhesions recruit the mechanosensory protein Vinculin to resist tension from the actomyosin cytoskeleton and avoid excessive disruption when the junctions transiently remodel in response to angiogenic growth factors and inflammatory cytokines. You can watch the video below, or subscribe in iTunes. (And remember, if you'd like to present this paper to your colleagues in a journal club, you can download everything you need - including a pdf of the paper and a PowerPoint file of all the figures - by clicking here to download our monthly Journal Club Pack).

And, finally for today, this issue's review by Richard Hynes on the evolution of the extracellular matrix is the last in our Evolution series (all articles are freely available here).  I'll let our reviews editor, Priya Prakash Budde, give you a quick series recap:

We have gotten a lot of great feedback on the series that started last summer with the evolution of membrane architecture (with a superbly funny title) from Field, Sali and Rout.  This was followed by the evolution of cadherins from Oda and Takeichi.  Masatoshi Takeichi discovered cadherins so it was a particular pleasure to have him write this article.  Next up Carvalho-Santos et al. traced the origins of centrioles, cilia, and flagella; this article was even mentioned in Carl Zimmer's blog The Loom.  We then moved on to the evolution of the cytoskeleton from Wickstead and Gull, and the nucleus from Wilson and Dawson.  The penultimate article in the series, from Rojas et al., was the evolution of the Ras superfamily-a heroic effort analyzing this huge family of proteins.  All of the articles use the amazing power of comparative genomics to provide a 'big picture' conceptual view of these topics.  One of the authors even said that writing the article made them think differently about their research.  I can't think of a better testimonial than that!  So, please check out the series and let us know what you think.

Lots of other interesting papers in today's new issue as well. You can find them all on our table of contents, by clicking here.

Cover image courtesy of Anjali Sarkar.

 

 

 

 

 

New issue: March 5th

In today’s new issue of JCB, Chan et al. describe how several protein complexes cooperate to stably attach spindle microtubules to kinetochores. The researchers show that the KMN network of kinetochore proteins recruits the microtubule-binding Ska complex in order to form stable connections to spindle fibers, and that this is blocked by the mitotic kinase Aurora B. More here.

Huveneers et al. reveal that the mechanosensory protein vinculin is recruited to specialized contacts between endothelial cells called focal adherens junctions (FAJs). Vinculin is recruited in response to tension from the actomyosin cytoskeleton, and it serves to reinforce FAJs, preventing them from being pulled too far apart when endothelial contacts are remodeled in response to cytokines or endothelial growth factors. You can read more in this summary.

And Gault et al. describe how the enzyme casein kinase 1 gamma regulates polarized vesicle trafficking in Drosophila wing cells, in order to ensure that each cell forms a single, actin-based protrusion called a trichome. The kinase works in parallel with the planar cell polarity pathway, which positions the trichome in the right part of each wing cell. You can learn more about how the two pathways work together in this week’s In Focus.

Alvarez et al. reveal how sperm navigate toward their target along a chemoattractant gradient. Factors released from the egg induce changes in the calcium concentration within sperm that alter the beating pattern of the sperm’s flagellum. But, as explained in this summary, Alvarez et al. show that it’s the rate at which intracellular Ca2+ levels rise and fall that matters, rather than the absolute concentration of calcium ions.

Meanwhile, Gervasi et al. describe how the transcription factor JunB initiates epithelial-mesenchymal transition downstream of TGFbeta signaling. You can learn more in this month’s biobytes podcast, where you can also hear Barry Ganetzky discuss his lab’s recent paper (Chen and Ganetzky) revealing that neuropeptides – best known for their role in modulating synaptic transmission – can also regulate synaptic growth and development. You can listen to the podcast below, or subscribe in iTunes.

There’s lots of other interesting papers to discover in this week’s new issue. You can find them all listed on our table of contents by clicking here.

Cover image courtesy of Stephan Huveneers.

New issue: February 6th

In today’s new issue of JCB, Zhang et al. reveal that inhibitors of a metabolic enzyme restore mRNA nuclear export to cells infected with the influenza virus. The flu virus shuts off gene expression in its host cell by producing a protein called NS1 that inhibits the processing and nuclear export of host cell mRNAs. Zhang et al. find that inhibitors of dihydroorotate dehydrogenase, an enzyme required for the de novo synthesis of pyrimidines like cytosine and thymine, restore mRNA export to infected cells and inhibit viral replication, in part by boosting levels of an mRNA export factor.  More here.

Oakes et al. suggest that actin filament stress fibers may serve as templates to promote the growth and maturation of focal adhesions. As described in this week’s In Focus, focal adhesions fail to mature in cells unable to form stress fibers near nascent cell attachments. Myosin II-generated tension has been thought to play a vital role in driving maturation, but Oakes et al. show that tension is still transmitted to focal adhesions in the absence of radial stress fibers, and tension can be reduced by as much as 80% without inhibiting adhesion maturation. “You need a sufficient amount of tension… but maturation isn't a tension-dependent process above that threshold,” says senior author Margaret Gardel, who thinks that the radial stress fibers may serve as structural templates to recruit additional focal adhesion proteins.

Staying with focal adhesions, Wang and McNiven describe how they recruit a matrix metalloproteinase to degrade the extracellular matrix and promote tumor cell invasion. The protease MT1 is brought to cell-matrix attachments by the focal adhesion proteins p130Cas and FAK, and it digests the surrounding ECM independently of another matrix-degrading structure in tumor cells, the invadopodium. You can read more in this summary, in which senior author Mark McNiven suggests that focal adhesions could cluster at the leading edge of invading cells to clear a path through the ECM.

Elsewhere, Ivanovic et al.describe how a glial cytoskeletal adaptor protein called 4.1G helps to spatially organize membrane proteins in both myelinating Schwann cells and the neuronal axons they ensheath. (Summary here). Nechipurenko and Broihier reveal that the transcription factor FoxO limits the stability of neuronal microtubules, and that this activity is restricted when neurons suffer cytoskeltal damage. And Christis and Munro show that the Arl1 GTPase controls the local activation of another small G protein, Arf1, to promote the formation of transport vesicles at the trans face of the Golgi apparatus. You can learn more about these latter two papers from the authors themselves, who feature in this month’s biobytes podcast. Listen below or subscribe in iTunes.

Cover image courtesy of Yvonne Beckham and Patrick Oakes.

 

 

New issue: January 9th

In today's new issue of JCB, Hayakawa et al. reveal that half of all the proteins that form the budding yeast nuclear pore complex are either mono- or poly-ubiquitinated. And they describe in detail how the ubiquitination of one pore component, Nup159, helps recruit dynein to the nuclear envelope in order to orient the spindle and move the nucleus to the bud neck during mitosis. More details here.

Ardite et al. describe how increased production of a microRNA leads to progressive muscle deterioration in Duchenne muscular dystrophy patients. As patients age, their damaged muscle cells are gradually replaced by collagen-rich fibrous tissue. Ardite et al. show that the cytokine TGFbeta induces this muscle fibrosis in part by stimulating production of the microRNA, miR-21, which increases fibroblast proliferation and boosts collagen production. You can read more in this summary.

Tang and Brieher reconstitute the assembly of actin filaments at intercellular junctions in vitro, and use their assay to identify key roles for the Arp2/3 actin nucleation complex and the actin-bundling protein alpha-actinin-4 in the process. These two proteins help assemble actin filaments at the junctions themselves, rather than capturing filaments formed nearby in the cytosol. Moreover, as described in this week's In Focus, the researchers find that versions of alpha-actinin-4 containing a mutation associated with human kidney disease inhibit actin assembly at adherens junctions in vitro and in vivo.

Wynne et al. image the movements of homologous chromosomes in living nematodes in order to describe how they pair up at the beginning of meiosis. These movements rely on chromosome sequences called pairing centers that coupled by a network of proteins across the nuclear envelope to dynein motors and microtubules in the cytoplasm. Dynein is shown to drive rapid, directional movements of the chromosomes to help them pair up with their homologues, but the chromosomes also show slower, dynein-independent motions that help them to pair up even in the absence of the motor protein. More here.

And Arsic et al. reveal a surprising new function for Cyclin A2, a protein best known for regulating cyclin-dependent kinases (CDKs) to control progression through the cell cycle. The researchers show that Cyclin A2 also has a CDK-independent function in inhibiting cell migration by potentiating a guanine nucleotide exchange factor that activates the RhoA GTPase. You can find out more in this month's biobytes podcast, where you can also learn about Giagtzoglou et al.'s paper describing a protein called dEHBP1, which regulates Notch signaling by promoting the exocytosis and recycling of the transmembrane ligand Delta.

There's lots of other interesting papers in today's new issue - you can find them all on our table of contents by clicking here.

Cover image courtesy of David Wynne and Ofer Rog.

New issue: December 26th

In today’s new issue of JCB, Hégarat et al. describe how the Aurora family of protein kinases regulates chromosome and microtubule dynamics in mitosis. Cells lacking either Aurora A or Aurora B fail to properly align their chromosomes on the mitotic spindle, resulting in chromosome mis-segregations. As described in this summary, cells lacking Aurora A AND Aurora B, on the other hand, fail to depolymerize spindle microtubules in anaphase, preventing sister chromatid separation.

Schmidt et al. describe a signaling pathway that helps embed acetylcholine receptors in the post-synaptic membrane of neuromuscular junctions. Neuregulin signaling molecules bind to their ErbB receptors and induce the phosphorylation of a post-synaptic scaffold protein called alpha-dystrobrevin1, which stabilizes acetylcholine receptors at the post-synapse to maintain proper synaptic neurotranmission. As explained in this week’s In Focus, the signaling pathway seems to particularly affect acetylcholine receptors that have undergone a round of endocytic recycling, though why this population of receptors behaves differently isn’t clear. Meanwhile, Baez et al. describe how cytoplasmic RNA granules regulate post-synaptic remodeling. The researchers identify S-foci, which contain the translational repressor Smaug1 and which regulate the local translation of mRNAs encoding proteins (e.g. CaMKinaseII) in response to NMDA receptor stimulation.

Emond et al. reveal a new way for cells to adhere to each other. Though classical cadherins like E- and N-cadherin are known to mediate intercellular adhesion, the role of the related protocadherin proteins in holding cells together is much less clear. Emond et al. find that Protocadherin-19 becomes adhesive when it forms a complex with N-cadherin, so that it forms homophilic adhesions between neighboring cells. N-cadherin switches on Protocadherin-19’s adhesive properties, but it doesn’t mediate the intercellular adhesion itself. More here.

Sideridou et al. report that Cdc6, a protein that permits cells to replicate their DNA, also induces epithelial to mesenchymal transitions by shutting down the expression of E-cadherin. Cdc6 overexpression may therefore aid the progression of cancer by stimulating both DNA synthesis and metastasis. You can find a longer summary here.

And Nekrasova et al. reveal that the two types of cadherin molecules that assemble into desmosomal adhesions are transported to the plasma membrane by two distinct kinesin motors. You can learn more in this month’s biosights, in which senior author Kathleen Green explains why using two independent transport mechanisms to build desmosomes might allow cells to tailor the strength of their adhesions during development and disease.

That’s all we have time for today, but you can find lots of other interesting papers in today’s new issue by visiting the table of contents here.

Cover image courtesy of Nadia Hégarat and Helfrid Hochegger.

New issue: December 12th

In today’s new issue of JCB, Gong et al. describe how a protein called Fsp27 promotes the growth of lipid droplets in fat-storing adipocytes. Fsp27 localizes to the site where neighboring droplets contact each other, and facilitates the transfer of lipids from the smaller to the larger droplet. More in this summary. Meanwhile, de Saint-Jean et al. describe how a protein called Osh4p exchanges sterols and phosphatidylinositol-4-phosphate between organelles in order to set up a sterol gradient across the different organelles of the secretory pathway. Tim Levine provides a comment on this surprising finding.

Bruns et al. identify a novel membrane-bound compartment in yeast called CUPS. This “Compartment for Unconventional Protein Secretion” contains many of the proteins required to deliver the Acyl-CoA-binding protein Acb1 to the surface of starving budding yeast via a recently-discovered pathway that sidesteps the usual secretory route through the ER and Golgi apparatus. You can learn more about the proteins that localize to CUPS, and how the organelle compares to similar compartments in the autophagy pathway, in this summary article.

And Garcia et al. reveal that the shape of septin filaments can be modulated by the incorporation of different septin subunits and by septin phosphorylation. Septins are a conserved family of GTPases that hetero-oligomerize into filamentous structures in order to control a variety of cellular processes, including budding yeast cytokinesis, where septins form an organized collar around the bud neck. Complexes containing the septin Cdc11 assemble into long, straight rods, but Garcia et al. find that substituting another septin, Shs1, in place of Cdc11 drives the formation of ring-shaped structures. Moreover, the phosphorylation of Shs1 can promote the assembly of septins into a gauze-like meshwork. Read more about how this all relates to septins’ functions at the yeast bud neck in this week’s In Focus.

Yamaguchi et al. perform some beautiful in vivo imaging to investigate how apoptosis contributes to neural tube closure in mouse embryonic brains (summary here) and Janes et al. examine the crosstalk between different subclasses of the Eph receptor tyrosine kinase family. This latter paper is covered in more detail in this month’s biobytes podcast, in which you can also hear Vania Braga describe her lab’s recent paper explaining how the cell junction protein Ajuba regulates the Rac GTPase at intercellular contacts. You can listen below or subscribe in iTunes.

That’s all for today, but don’t forget to check out all the other great papers published in today’s new issue. You can find them all on our table of contents.

Cover image courtesy of Zhiqi Sun.