Cover Picture: Proteomics 23'11

Summer/winter heads/homes My, such complex lives we lead when first we practice to finance another home. First, what do we call it when we have identical sequence proteins that reside in two or more separate chambers? – i.e. identical twins in nearly identical apartments, say one with and one without air conditioning) or (multiple identical individuals in different homes? Until recently this has been referred to as “protein dual localization”. What are “similarly localized proteins”? How about the same protein with different tags? Currently known as an “echoform”. (Read the discussion of both!) Why has the concept even come up? Because it does in life, particularly in mitochondrial assembly (Ben Menachem et al.). Molecular signaling mechanisms seem to require a new vocabulary to describe the subtle complexities of modern relationships. TV soap opera fratricides notwithstanding. Ben Menachem, R. et al., Proteomics 2011, 11 , 4468–4476. A pony not to pick Glioblastoma multiforme (GBM) is one of the closest cancers to a sure bet: it will be 80% fatal in 1–2 years after diagnosis. Recent work has indicated a role for brain cancer stem cells (CSC) in GBM but precisely which, of several, are most effective remains open. One clear pathway is Notch signaling which contributes its regulation of self‐renewal and cell fate determination for normal stem cells. Dai et al. had previously studied this problem and found a quantitative MS proteomic approach with stable‐label or label‐free detection methods worked well but for faster, more sensitive and more selective results, Multiple Reaction Monitoring was the method of choice. Dai, L. et al., Proteomics 2011, 11 , 4529–4540. Built to take the heat and the acid: Picrophilhus torridus Thürmer et al. report here on the proteome of an extremophile. Picrophilhus torridus was isolated from the most acidophilic environment discovered to date – temperatures up to 65°C, pH 0–1, and a genome of only 1.55 Mb. Soluble extracts taken at 50 and 70°C were analyzed by 2‐DE at pH 4–7 and pH 3–10 and 12% SDS‐PAGE. From the genomic sequence, the researchers were able to create virtual proteome maps of P. torridus at pH 4–7 and 3–10 that could be compared with the actual Coomassie‐stained gels. There were more similarities than differences when compared with other species. Possible chains of post‐translational modifications matched well. As had been seen elsewhere, adaptation to stress meant keeping the core structures stabilized with respect to the challenge. This is an efficient organism, as only single proteins needed to be up‐ or down‐shifted when conditions changed. Thürmer, A. et al., Proteomics 2011, 11 , 4559–4568.