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.
 | Cellular stress: Phosphatase receives an oxygen boost
The enzymatic activity of Sdp1, a phosphatase that acts on the yeast mitogen-activated protein kinase (MAPK) Slt2, is boosted by cysteine disulfide bridge formation under oxidative stress.
Original research paper: Nature 447, 487-492 (2007) |
 | Gastric epithelial cells: Losing shape with CagA-PAR1
The Helicobacter pylori virulence factor CagA interacts with the partitioning-defective (PAR1)/microtubule affinity-regulating kinase (MARK) in epithelial cells to cause defects in cell polarity and cell shape distortions.
Original research paper: Nature 447, 330-334 (2007) |
 | Tumorigenesis: Negative regulation by p38α
Two reports on the p38α mitogen activated protein kinase (MAPK) highlight its importance in preventing tumor formation and document a new role for it in antagonizing Jun N-terminal kinase (JNK) signaling.
Original research paper: Nature Neuroscience Genetics 39, 750-758 (2007) |
 | Genomic screens: The TAO1 of mitotic checkpoint signaling
A functional genomic screen using short hairpin RNA (shRNA) libraries directed against kinases and phosphatases has identified a role for the serine/threonine kinase TAO1 in the mitotic spindle checkpoint.
Original research paper: Nature Cell Biology 9, 556-564 (2007) |
 | Ageing: Similar signs
LAΔ50/progerin not only causes mitotic defects in the premature-ageing disorder Hutchinson–Gilford progeria syndrome but also causes similar defects in normal cells.
Original research paper: Proc. Natl Acad. Sci. USA 104, 4949–4954 (2007) |
 | Plant cell biology: Shedding light on auxin action
The structural determination of F-box protein transport inhibitor response-1 (TIR1) in complex with the adaptor protein ASK1 has revealed the mechanism of activation for TIR1 upon binding of the plant hormone auxin.
Original research paper: Nature 446, 640–645 (2007) |
 | In brief: May 2007
Calcium | DNA repair | T-cell responses | Genomic instability | Trial watch | Technology | Human disease | Polarity | Psychiatric disorders | Microglia | Imaging and visualization | Gene transfer
| Mast cells | Signalling | Tumorigenesis | Oxygen sensing | Tolerance | Regulatory T cells | Microarrays | Virology |
 | Innate immunity: Triggering RIG-I
The tripartite-motif-containing protein 25 (TRIM25) ubiquitylates retinoic-acid-inducible gene (RIG-I) to enable RIG-I to work in conjunction with mitochondrial antiviral signaling protein (MAVS) in viral defense.
Original research paper: Nature 446, 916-920 (2007) |
 | Immunotherapy: Beneficial loss
Removing the E3 ubiquitin ligase Cblb (Casitas B-lineage lymphoma b), which induces T-cell activation independently of CD28 co-stimulation, protects mice against different types of tumors.
Original research paper: J. Clin. Invest. 117, 1029–1036 (2007) |
 | Evolution: Duplicates provide only limited cover
A study using yeast has found that the ability of gene duplicates to compensate for gene loss is more limited than expected.
Original research paper: Mol. Sys. Biol. 3:86 (2007) |
 | Cell biology: Optical excitation yin and yang
A pair of photoreceptors — halo-rhodopsin from Natronomonas pharaonis (NpHR) and channelrhodopsin-2 (ChR2) — can selectively stimulate and inhibit a single neuron.
Original research paper: Nat. Neurosci. 8, 1263–1268 (2005) |
 | Cell death: The clock is ticking
The lifespan of platelets is determined by the interplay between the pro-survival BCL-XL and the pro-apoptotic BAK proteins.
Original research paper: Cell 128, 1173–1186 (2007) |
 | Tumorigenesis: Branching defects
Sprouty-2, an antagonist of the Ras–mitogen-activated protein kinase pathway, negatively regulates oncogenic K-Ras during development and tumorigenesis.
Original research paper: Genes Dev. 21, 694–707 (2007) |
 | Cell fate: Unlocking the right combination
Helix-loop-helix (HLH) transcription factors determine both the position of multipotent neuronal progenitor cells and timing of differentiation.
Original research paper: Development 134, 1617-1629 (2007) |
 | Protein–protein interactions: better by the dozen
A combined reanalysis of two large yeast protein-protein interaction studies provides a large consolidated data set, with a level of accuracy similar to small-scale experiments.
Original research paper: Mol. Cell. Proteomics 6, 439–450 (2007) |
 | Lymphocyte migration: Exiting lymphoid organs
Sphingosine-1-phosphate found in plasma and lymph acts directly on lymphocytes to induce their exit from the spleen and thymus.
Original research paper: Science 316, 295-298 (2007) |
 | P53: Heads or tails? You lose!
Gain-of-function mutations in the tumor suppressor p53 promote oncogenesis by interfering with DNA repair.
Original research paper: Nature Cell Biology 9, 573-580 (2007) |
 | Autoimmunity: Regulatory T cells in autoimmunity
During autoimmune disease, effector T cells at acute sites of inflammation produce high levels of tumor necrosis factor (TNF) and cytokines such as interleukin 6 (IL-6) that impede their suppression by regulatory T cells.
Original research paper: Nature Medicine 13, 423-431 (2007) |
 | Metastasis: To grow and spread
Gene expression analyses have uncovered a subset of genes that are required for metastasis but not primary tumor formation.
Original research paper: Nature 446, 765–770 (2007) |
 | Anticancer drugs: Mitotic arrest
A pharmacologic inhibitor of polo-like kinase 1 (PLK1) inhibits tumor growth by promoting mitotic arrest.
Original research paper: Curr. Biol. 17, 316–322 (2007) |
 | Cell biology: Too much of a good thing
Cells cultured at atmospheric, rather than physiologic oxygen concentrations may have divergent reactions to stimuli, confounding efforts to study signal transduction in vitro.
Original research paper: Proc. Natl. Acad. Sci. USA 104, 4547–4552 (2007) |
 | Cytoskeleton: Reshaping membranes
The actin-binding proteins missing-in-metastasis (MIM) and insulin receptor substrate p53 (IRSp53) bind to membrane lipids to promote the formation of filopodia.
Original research paper: J. Cell Biol. 8, 37–48 (26 March 2007) |
 | T cells: LIGHTing up lipid metabolism
Lipid metabolism is regulated by tumor necrosis factor (TNF) signaling through lymphotoxin-β receptors in T cells, providing a link between the TNF superfamily pathway and development of dyslipidemias.
Original research paper: Science 316, 285–288 (2007) |
 | Expression profiling: Relative significance
Gene expression profiling of breast cancer cells has documented a correlation between poor prognosis, and the expression of the cell surface marker CD44, transforming growth factor β 2 and stem cell markers.
Original research paper: Cancer Cell 11, 259–273 (2007) |
 | Cancer genetics: Micro enhancement
Global repression of micro RNAs potentiates heightened cellular transformation of lung cancer cell lines through increased expression of K-Ras and Myc.
Original research paper: Nature Genet. 6, 857–866 (1 April 2007) |
 | Mutagenesis: Designer receptors for every body
Researchers have used mutagenic PCR to create 'designer' receptors that are specifically activated by a ligand with no other biological activity in the cell.
Original research paper: Proc. Natl. Acad. Sci. USA 104, 5163–5168 (2007) |
