Research Highlights

Short, accessible synopses of recent important articles concerning signalling pathways.

November 2008

• Calcium: An effective get-together

  

  The release of calcium (Ca²⁺) from the endoplasmic reticulum (ER) is followed by the influx of Ca²⁺ across the plasma membrane through Ca²⁺-release-activated Ca²⁺ (CRAC) channels, which are crucial for sustained Ca²⁺ signalling in many cell types. Three studies now provide new insights into how Ca²⁺ depletion is sensed in the ER and discover a unique mechanism for ion channel assembly and activation.

  Original research paper Nature Reviews Molecular Cell Biology 9 824 doi:10.1038/nrm2540

• Membrane trafficking: Recycling integrins

  

  Although it is now well established that vesicular transport has important roles in both cell migration and cytokinesis, the mechanisms by which this occurs remain mostly unclear. Two studies now provide insights into the regulation of integrin trafficking in both processes by the Rab family of small GTPases. Caswell et al. show that Rab-coupling protein (RCP) coordinates endocytic recycling of integrins and promotes tumour cell migration, whereas Pellinen and colleagues highlight a role for integrin trafficking in cell division by showing that RAB21-regulated integrin trafficking is essential for cytokinesis.

  Original research paper Nature Reviews Molecular Cell Biology 9 826 - 827 doi:10.1038/nrm2537

• Lipid metabolism: Treasure hunt in fat

  

  Deregulation of lipid metabolism in individual tissues causes metabolic diseases, such as diabetes, fatty liver disease and atherosclerosis. How do alterations in tissue-specific lipid metabolism affect whole-body homeostasis? Now, Cao et al. show that palmitoleate is an adipose tissue-derived hormone that regulates systemic metabolic homeostasis.

  Original research paper Nature Reviews Molecular Cell Biology 9 826 - 827 doi:10.1038/nrm2533

• Tumorigenesis: Keeping a watchful eye

  

  Disruptions in the delicate balance between keratinocyte proliferation and differentiation can contribute towards the development of squamous cell carcinoma (SCC) of the skin — a common human malignancy. It has been proposed that innate surveillants, molecules that promote terminal keratinocyte differentiation, exist in the skin to prevent carcinogenesis, but the conclusive identification of such proteins has not yet been achieved.

  Original research paper Nature Reviews Cancer 8 829 doi:10.1038/nrc2530

• Lymphocyte responses: Germinal-centre B cells take control

  

  The pro-apoptotic receptor CD95 (also known as FAS) is crucial for maintaining homeostasis of peripheral lymphoid organs, as indicated by the lymphoproliferative syndrome that occurs in humans and mice deficient for CD95 or its ligand. A new study in Immunity shows that CD95 deficiency in B cells alone can result in both B- and T-cell dysfunction, which is in contrast to the previously held assumption that CD95 deficiency in T cells is responsible for the lymphoproliferation.

  Original research paper Nature Reviews Immunology 8 826 - 827 doi:10.1038/nri2441