Cover Picture: Proteomics 12'09

Abstract

AbstractEvolving backwards: Mycobacterium lepraeMycobacterium leprae is responsible for at least 300 000 new cases per year of leprosy (Hanson's disease). A Gram‐positive bacillus, M. leprae has not been cultured in vitro: it is known to grow only in humans, mice and nine‐banded armadillos, and, even there it is an obligate intracellular pathogen. The bacterium must have become an obligate intracellular organism relatively recently, judging by the number of pseudogenes and substantial gene decay found in the genomic sequence. As a result of this, there have been differences in the determinati on of valid open reading frames (ORFs) from various research groups. de Souza et al. have applied proteomic techniques to sort out the confusion. The ORFs of all six reading frames at least 20 codons long were carefully examined as potential peptide sources by LTQ‐LC‐MS/MS. The authors found 1046 different proteins, confirming others' findings with tuberculosis, a similar bacterium.de Souza, G. A. et al., Proteomics 2009, 9, 3233–3243.Eeny, meeny, miney, moe, catch a neighbor by the toeOnce you have networked him, be sure to let him go... Well, it almost scans. And, if you don't release him, you may be missing a minimum of one node and two links in a critical neural network. In this particular example, I know you will have a misfiring neuron because the sample is purified presynaptic nerve terminals from the hippocampus. How do I know? Because the target was purified and characterized by proteomic procedures according to Abul‐Husn et al., authors of this paper. They used a very selective way to purify the presynaptic proteins and validate the sample, they manually validated the system by reviewing the biochemistry and physiology publications on experimental protein‐protein interactions, and they applied computational graph theory analysis. For good measure, they also checked the gene ontology. Final result: 50 new candidates not previously recognized as presynaptic were identified by shared neighbor analysis.Abul‐Husn, N. S. et al., Proteomics 2009, 9, 3303–3315.Shocking behaviorThe heat shock proteins (hsp) are a family of proteins that developed very early in evolution, appearing in all kingdoms. They play many roles in cells, ranging from protection against a variety of types of stress, directing proper refolding of partially denatured or newly synthesized proteins, to presentation of antigens. In this paper, Trott et al. use proteomic and genetic tools to examine the role of hsp27 in the growth of human endothelial and smooth muscle cells. More particularly, they work with hypo‐ and hyper‐phosphorylated, and anti‐sense knock out mutants engineered into adenovirus vectors. Findings observed on cultured cells were confirmed in vivo. Some interesting proteins surfaced (stathmin, cofilin, and ubiquitin enzymes) which will require more study.Trott, D. et al., Proteomics 2009, 9, 3383–3394.