In this week's Science, a team of researchers led by Stockholm Royal Institute of Technology researcher Mathias Uhlén presents a tissue-based map of the human proteome, offering insights into protein expression across 32 human tissues. The resource was built with RNA expression data, which corresponds to protein production, and used antibodies to identify which proteins were active in which tissues down to the single-cell level. The map reveals which proteins are expressed across all tissues, indicating a housekeeping function, and which are tissue-specific. The map will be made available as part of the Human Protein Atlas. GenomeWeb has more on this human proteome map here.
Also in Science, a group from the Max Planck Institute of Biochemistry describes the use of electron cryotomography to look at the activity of the 26S proteasome, a key player in eukaryotic protein quality control and various cellular processes, in hippocampal neurons. They found that the proteasome system is only partially used when it is not under stress, and that hippocampal neurons only use about 20 percent of their proteasomes when they are in an unstressed state.