Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
and JavaScript.
Owing to the toxic potential of unfolded proteins, their accumulation in the endoplasmic reticulum activates a cellular stress response. This unfolded protein response remodels the secretory pathway to accommodate the load of unfolded proteins or, if the burden is insurmountable, promotes cell death to protect the organism.
Protein kinases must recognize their correct substrates in a massive background of other potentially phosphorylatable sites. A multitude of mechanisms have evolved to regulate specificity. Individually they are imperfect, but together they coordinate protein phosphorylation with exquisite precision.
Drosophila melanogasterhaemocytes operate as the first line of defence against invading microorganisms during larval and adult life. However, in the developing embryo, haemocytes undergo complex migrations and carry out several non-immune functions that are crucial for successful development.
Although it is now accepted that the infectious agent that causes transmissible spongiform encephalopathies is PrPSc, recent insights into the existence of prion strains pose a fascinating challenge to prion research. What is the nature of prion strains? And how can they be discriminated?
Intermediate filaments (IFs) are thought to function as absorbers of mechanical stress and form cytoskeletal networks that serve to support cell shape. The analysis of disease-causing mutations in IF proteins has revealed that IFs also have important roles in cell-type-specific physiological functions.
Nucleoli are the sites of ribosome-subunit biogenesis, but recent large-scale proteomics analyses and other studies have revealed further cellular functions, including cell-cycle control, stress responses and coordination of the processing and maturation of other classes of ribonucleoprotein in addition to the ribosomal class.
SOS mutagenesis is the 'mutation-prone' cellular replication mechanism that is responsible for UV-induced mutations. More than 50 years of SOS mutagenesis research has exposed the underlying mechanisms of DNA-damage-induced mutagenesis that combine the overlapping functions of replication, repair and recombination.
