These short, accessible highlights summarize and contextualize must-read papers related to cell signaling. These articles add background and context to summaries of primary research. 'In brief' articles emphasize key aspects of selected articles.
 | Eye development: Purinergic receptor signaling regulates Pax6
Eye development in Xenopus is coordinated by the hydrolase E-NTPDase2 and the P2Y1 purinergic receptor, which promotes the expression of the transcription factor Pax6.
Original research paper: Nature 449, 1058-1062 (2007) |
 | Cardiac morphogenesis: What your heart Wnts
Wnt11 regulates heart morphogenesis by integrating both canonical and non-canonical Wnt signaling with TGFβ signaling.
Original research paper: Nature Genetics 39, 1225-1234 (2007) |
 | Protein degradation: Merlin performs a double Akt
The protein kinase Akt promotes both the phosphorylation and ubiquitin-mediated degradation of the tumor-suppressor protein merlin.
Original research paper: Nature Cell Biology 9, 1199-1207 (2007) |
 | MicroRNA: A new Twist on invasion and metastasis
The microRNA miR-10b indirectly regulates RhoC expression to promote tumor cell invasion and metastasis, documenting a novel role for microRNAs in regulating migration and motility, and exposing their involvement at several different stages of tumor formation and progression.
Original research paper: Nature 449, 682-688 (2007) |
 | T Cells: Co-receptor tuning
Expression of the T-cell co-receptor CD8 is controlled by a negative-feedback circuit that regulates the reactivity of CD8+ T cells, ensuring that the T cells maintain a self-reactive yet self-tolerant phenotype.
Original research paper: Nature Immunol. 8, 1049–1059 (2007) |
 | Therapy: I look down on him...
Expression profiling of the BCL2 family of cell death proteins can be used to identify several physiological parameters of human cells, including their propensity to undergo apoptosis and sensitivity to the experimental anti-tumor drug ABT-737.
Original research paper: Cancer Cell 12, 171–185 (2007) |
 | In brief: October 2007
Post-translational modification | MicroRNA | Dendritic cells | Metastasis | Therapy | Leukaemia | Gene regulation | Developmental biology | Molecular neuroscience | Neurodegenerative disease | G-protein-coupled receptors | Protein biochemistry | Virology |
 | Angiogenesis: Inside or outside?
Autocrine vascular endothelial growth factor (VEGF) signaling is required for vascular homeostasis, but not for pathological angiogenesis, suggesting that anti-VEGF cancer therapies might promote different responses depending on their mechanism of action.
Original research paper: Cell 130, 691–703 (2007) |
 | Developmental biology: microRNAs create major divisions in embryogenesis
During vertebrate development, asymmetrical Wnt signaling regulates the distribution of microRNAs miR-15 and miR-16, which in turn downregulate the activin A receptor to establish a Nodal signaling gradient.
Original research paper: Nature 449, 183–188 (2007) |
 | Chemosensation: Sensing sugar in the brain
Glucose sensitivity is dictated by the closure of neuronal ATP-sensitive potassium channels; uncoupling protein 2 (UCP2) activity, which lowers ATP yield and thus decreases glucose sensitivity, is thought to be important in glucose homeostasis.
Original research paper: Nature 449, 228–232 (2007) |
 | Imaging: Hide and seek with cysteines
To identify proteins that undergo structural changes in perturbed cells, researchers examined in vivo fluorophore labeling of normally shielded cysteines by fluorescence microscopy and mass spectrometry.
Original research paper: Science 317, 663–666 (2007) |
 | Development: It's not just a gap
Studies on the gap-junction subunits connexin-26 and connexin-43 reveal that the adhesive, but not the channel, properties of gap junctions are essential for neural migration.
Original research paper: Nature 448, 901–907 (2007) |
 | Innate immunity: An unexpected role for NF-κB
The functional elimination of IKKβ (inhibitor of nuclear factor-κB (NF-κB) kinase-β) — an effector of NF-κB-mediated inflammation — makes mice more susceptible to endotoxin-induced shock because of an increase in the level of circulating interleukin-1.
Original research paper: Cell 130, 918–931 (2007) |
 | Targeted therapy: Blast it away!
Reactivating the tumor-suppressor protein phosphatase 2A (PP2A) induces apoptosis in chronic myeloid leukemia-blast crisis and Philadelphia chromosome positive acute lymphocytic leukemia (Ph1ALL) cell lines, as well as in cells from patients.
Original research paper: J. Clin. Invest. 117, 2408–2421 (2007) |
 | Psychiatric disorders: Modelling compulsive behaviour
Mice lacking a component of the excitatory postsynaptic density (PSD), SAP90/ PSD95-associated protein 3, exhibit some of the features of obsessive compulsive disorder (OCD) and could provide new insights into OCD pathogenesis.
Original research paper: Nature 448, 894–900 (2007) |
 | Cancer: On the move
The neurotrophin receptor p75 is involved in axonal outgrowth, neuronal survival, tumorigenesis and in non-neuronal types of cancer, and is a likely mediator of glioma cell invasion.
Original research paper: PLoS Biol. 5, 1723–1737 (2007) |
 | Bacterial virulence: Shigella shoots, Shigella scores
The effector invasion plasmid antigen B, which targets the activity of the anaphase-promoting complex, retards cell-cycle progression and promotes bacterial colonization of the intestinal epithelium by Shigella flexneri.
Original research paper: Cell 130, 611–623 (2007) |
 | Post-translational modification: The importance of being inactive
The ubiquitin E3 ligase SMURF2 is regulated by an autoinhibitory mechanism that prevents SMURF2 and its substrates from being ubiquitinated and degraded in an unregulated manner.
Original research paper: Cell 130, 651–662 (2007) |
 | T-Cell development: Thymocyte-selected CD4+ T cells
Thymocyte-selected CD4+ T cells from mice engineered to express MHC-class-II-positive thymocytes retain characteristics of T helper 1 (TH1) and TH2 cells as they produce produce both interleukin-4 (IL-4) and interferon-γ (IFNγ).
Original research paper: J. Exp. Med. 204, 2145–2157 (2007) |
 | Oncogenes: Suppressive organization
The cell polarity protein LKB1 establishes epithelial cell polarity in three-dimensional cell culture, which suppresses the apoptotic and oncogenic activity of c-Myc.
Original research paper: Proc. Natl Acad. Sci. USA 104, 14694–14699 (2007) |
 | Gene regulation: Differentiating the core machinery
The canonical TFIID transcription factor complex is downregulated during muscle cell differentiation, with alternative components taking over the task of recognizing core promoter sequences to direct the expression of muscle-specific genes.
Original research paper: Genes Dev. 21, 2137–2149 (2007) |
 | Neurodegenerative disease: Death receptor takes centre stage
Mice that lack the tumor necrosis factor type 1 death receptor (TNFR1) are protected from the development of amyloid-β-related pathologies, suggesting that TNFR1 might be a central mediator of Alzheimer's disease.
Original research paper: J. Cell Biol. 178, 829–841 (2007) |
 | Chemical biology: From structure to function
By docking potential substrates into the active site of an enzyme of known structure, researchers accurately predict the catalytic activity of the enzyme.
Original research paper: Nature 448, 775–779 (2007) |
 | Cell division: CDK1 in the driving seat
While the cell division kinase CDK1 is indispensible for cell division, mouse cells that concurrently lack the three interphase kinases CDK2, CDK4 and CDK6 divide slowly, but otherwise normally.
Original research paper: Nature 448, 811–815 (2007) |
 | Tumour suppressors: One faulty copy tips the balance
The acetyl transferase Tip60, which regulates transcription of Myc and p53, functions as a tumor suppressor independent of Myc or p53.
Original research paper: Nature 448, 1063–1067 (2007) |
 | Immunology: 'Danger' signals
Chemotherapy-induced cell death triggers the release of the high-mobility group box 1 protein (HMGB1), which stimulates Toll-like receptor 4 (TLR4) and elicits an immune response that is required for the success of the therapy.
Original research paper: Nature Med. 13, 1050–1059 (2007) |
 | Genetic instability: Genomic instability links diet to cancer
A genetic screen in yeast has found a surprising link between the gene encoding a putative pyridoxal kinase (Pdxk) and increased genome instability, providing a link between vitamin B6 deficiency and cancer.
Original research paper: PLoS Genet. 3, e134 (2007) |
 | Stem cells: Intrinsically different
A new technique for generating neurons from human embryonic stem cells (hESCs) demonstrates that distinct populations of hESCs develop into neurons with strikingly different gene expression profiles.
Original research paper: Proc. Natl Acad. Sci. USA 104, 13821–13826 (2007) |
 | Host response: Genital herpes takes its toll
Genetic variation in the Toll-like receptor 2 (TLR2) gene is associated with increased shedding and lesion occurrence rates in patients infected with herpes simplex virus type-2 (HSV-2).
Original research paper: J. Infect. Dis. 196, 505–509 (2007) |
