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.
 | Membrane trafficking: PSD-95 TRKs to synapses
The PI3K–Akt signaling pathway promotes membrane localization of postsynaptic density protein 95 (PSD-95) in response to N-methyl-D-aspartate receptor (NMDAR) and brain-derived neurotrophic factor (BDNF)–TrkB pathway activation.
Original research paper: Nature Neuroscience 10, 702-711 (2007) |
 | Type 2 diabetes: Insulin Akts on PGC-1α
Phosphorylation of the transcription factor PGC-α by Akt/PKB suppresses fatty acid oxidation and gluconeogenesis in hepatic cells.
Original research paper: Nature 447, 1012-1016 (2007) |
 | Membrane targeting: Sos takes a trip on (phosphatidic) acid
Two reports describe a new role for phospholipase D2 (PLD2) in promoting membrane association of guanine nucleotide exchange factors (GEFs) and Ras activation.
Original research paper: Nature Cell Biology 9, 707-712 (2007) |
 | MicroRNA: A new component of the p53 signaling pathway
Three microRNA (miRNA) molecules have been validated as direct transcriptional targets of the p53 tumor suppressor protein, establishing a novel mechanism of p53-mediated growth arrest in mammalian cells.
Original research paper: Nature 447, 1130-1134 (2007) |
 | CARD9: Stacking the deck in myeloid cells
The adaptor protein CARD9 couples the activation of membrane receptors to divergent signaling cascades in myeloid cells.
Original research paper: Nature Immunology 8, 619-629 (2007) |
 | Immune regulation: Terminating inflammatory responses
The nuclear protein PDLIM2 acts as an E3 ubiquitin ligase for the p65 subunit of nuclear factor-κB and promotes its degradation.
Original research paper: Nature Immunol. 8, 584–591 (2007) |
 | Senescence: Arrest me!
Induction of senesence, whether through high expression of oncogenes or through shortened telomeres, limits tumorigenesis in a p53-dependent manner.
Original research paper: Cancer Cell 11, 461–469 (2007) |
 | In brief: June 2007
Endocytosis | Cell division | Epigenetics | Evolution | T-cell development | Autoimmunity | Immune regulation | MicroRNA | Therapy | Leukemia | Plant genetics | Gene regulation | Development | Ion channels | Addiction | Neurodegenerative disorders | Learning and memory | Psychiatric disorders | Angiogenesis | Learning and memory | Neurological disease | Gene regulation | Genomics | Techniques & applications | Bacterial pathogenesis |
 | Breast cancer: AKT1 wears many hats
Akt1 is required for breast cancer metastasis in mouse models that overexpress ErbB2/Her2.
Original research paper: Proc. Natl Acad. Sci. USA 104, 7438–7443 (2007) |
 | Psychiatric disorders: Understanding white matter defects
Expression of a dominant-negative ErbB4 receptor leads to increased expression of the dopamine transporter (DAT) and dopamine D1-like receptors, highlighting a potential role for ErbB4 in psychiatric disorders.
Original research paper: PNAS 104, 8131–8136 (2007) |
 | Cell biology: Catching up to the speed of signaling
A simple, continuous quench-flow system allows quantitative analysis of very early cellular signaling events.
Original research paper: Nat. Biotechnol. 25, 566–568 (2007) |
 | Innate immunity: Pannexin-1: the missing link?
Cryopyrin functions downstream of pannexin-1 and ATP to regulate caspase-1 activation in response to bacterial components that are detected in the cytosol.
Original research paper: Immunity 26, 433–443 (2007) |
 | Tumorigenesis: Taking the hallmark?
A Myc-dependent pathway that is required to downregulate the tumor suppressor p27 and hence propagates lymphomagenesis has been identified.
Original research paper: EMBO J. 26, 2562–2574 (2007) |
 | Metabolism: A subtle role for HIF1α
HIF1α's function of regulating glucose metabolism in hypoxic cells is governed by growth factor availability.
Original research paper: Genes Dev. 21, 1037–1049 (2007) |
 | Gene regulation: A multilayered take on gene expression
A study collecting quantitative, global measurements at different stages during protein production has provided new insight into how gene regulatory mechanisms in eukaryotic cells are coordinated at multiple levels.
Original research paper: Mol. Cell 26, 145–155 (2007) |
 | Memory: Neurons enter memory competition
Neurons compete to take part in fear memory formation, and a neuron's level of the transcription factor cyclic AMP-response element binding protein (CREB) influences whether it is likely to win.
Original research paper: Science 316, 457–460 (2007) |
 | Addiction: Learning to be addicted
Drugs-of-abuse target dopaminergic ventral tegmental area (VTA) neurons that are modulated by the long-term potentiation (LTP) of inhibitory synapses, suggesting a mechanism by which opioids deregulate neuronal activity, leading to addiction.
Original research paper: Nature 446, 1086–1090 (2007) |
 | Lead discovery: Screening by signature
Screening small-molecule libraries for gene-expression signatures indicative of oncoprotein inactivation has presented the first oncoprotein-modulating drug candidate.
Original research paper: PLoS Med. 4, e122–1935 (2007) |
 | Bacterial pathogenesis: Plant pathogen counter-attacks
The plant pathogen Pseudomonas syringae injects the ADP–ribosyltransferase (ADP–RT) HopU1 into plant cells through its type III secretion system (T3SS) to suppress the plant's innate immunity.
Original research paper: Nature 447, 284–288 (2007) |
 | DNA repair: New players complement the team
Several new factors have been identified that are crucial for the DNA-damage response associated with Fanconi anemia, a chromosome instability and development disorder.
Original research paper: Cell 129, 289–301 (2007) |
 | Immune regulation: MicroRNAs and the immune response
The microRNA-155, known to be expressed in human B-cell lymphomas and in activated mature B and T cells, has a role in regulating T-cell-dependent antibody responses and immune-cell function.
Original research paper: Science 316, 604–608 (2007) |
 | Hypoxia: Opposing effects
Progressing renal-cell carcinomas maintain hypoxia-inducible factor (HIF)2α but lose HIF1α expression during progression due to their opposing effects on MYC.
Original research paper: Cancer Cell 11, 335–347 (2007) |
 | Therapy: Addicted to repair
Loss of the Fanconi anemia (FA) DNA damage response (DDR) is connected with an inherited predisposition to cancer, although other DDR pathways have now been identified that compensate for this loss.
Original research paper: J. Clin. Invest. 117, 1440–1449 (2007) |
 | Neuronal migration: Signalling retreat
The SLIT2–ROBO interaction may coordinate long range neuronal migration by increasing intracellular Ca2+ and upregulating RhoGTPases within seconds of SLIT2 exposure.
Original research paper: Cell 129, 385–395 (2007) |
 | Inflammatory diseases: MIF's receptors revealed
The cytokine macrophage migration inhibitory factor (MIF), a crucial factor in inflammatory diseases, has been identified as a ligand for the CXC-chemokine receptors CXCR2 and CXCR4.
Original research paper: Nature Med. 13, 587–596 (2007) |
 | Cell biology: A gentle touch for cells
A new micromechanical device allows precise spatial and temporal control of cell–cell contact.
Original research paper: Proc. Natl. Acad. Sci. USA 104, 5722–5726 (2007) |
 | Cell signalling: New communication skills
Small, secreted vesicular bodies known as exosomes can be packaged with mRNA and microRNA to provide a novel mechanism of cell-to-cell communication.
Original research paper: Nature Cell Biol. 9, 654–659 (2007) |
 | Tumour immunology: DCs under the influence
Interleukin-13 (IL-13) and phosphorylated signal transducer and activator of transcription 6 (STAT6) are secreted by breast cancer cells, resulting in the induction of CD4+ T cells and tumorigenesis.
Original research paper: J. Exp. Med. 204, 1037–1047 (2007) |
 | Drug resistance: Alternative routes
Oncogenic mutations in the receptor tyrosine kinase MET activate the epidermal growth factor receptor (EGFR) pathway through ERBB3, delineating a new mechanism for acquired EGFR-inhibitor resistance in non-small cell lung cancer.
Original research paper: Science 316, 1039–1043 (2007) |
 | Molecular neuroscience: Homer's alcohol connection
Decreased neural expression of the scaffolding protein Homer in Drosophila after exposure to ethanol implicates it in the regulation of fruit fly sensitivity and tolerance to alcohol.
Original research paper: J. Neurosci. 27, 4541–4551 (2007) |
 | Proteomics: From spectral networks to shotgun sequencing
Researchers harness the power of mass spectrometry to quickly sequence proteins and identify their post-translational modifications.
Original research paper: Proc. Natl. Acad. Sci. USA 104, 6140–6145 (2007) |
 | Stem cells: Sharing common factors for self-renewal
The transcription factor ZFX regulates the self-renewal capacities of adult hematopoietic and embryonic stem cells.
Original research paper: Cell 129, 345–357 (2007) |
 | Therapy: Synergy
Chemotherapy given in combination with ligands for the peroxisome proliferator-activated receptor-γ (PPARγ) synergistically inhibits the growth of lung and ovarian cancer cell lines.
Original research paper: Cancer Cell 11, 395–406 (2007) |
 | RNA world: MicroRNAs: unicellular organisms also have their share
The green alga Chlamydomonas reinhardtii is able to produce two hundred putative microRNA molecules, supporting a role for microRNA-based gene regulation among unicellular organisms.
Original research paper: Genes Dev. 21, 1190–1203 (2007) |
 | Vesicular trafficking: Traffic jam at the synapse
Neurotransmitter endocytosis at synaptic sites in adult neurons is dependent on the GTPase dynamin-1, indicating that it may be required for efficient synaptic transmission.
Original research paper: Science 316, 570–574 (2007) |
 | Bacterial pathogenesis: Pseudomonas makes its own bed
Binding of the Pseudomonas aeruginosa pathogen to the apical membrane promotes redistribution of phosphatidylinositol 3,4,5-triphosphate (PIP3) and concomitant loss of membrane polarity, which may potentiate its entry into epithelial cells.
Original research paper: J. Cell Biol. 177, 21–27 (2007) |
