A group of  24 researchers affiliated to UT Southwestern Medical Center and 16 other institutions including one each from the UK and the Netherlands  have identified a peptide showing a therapeutic potential against neurological disorder, infectious disease and cancer. This paper was published 14 February 2013  in Nature ( 494: 201–206). This finding is regarded as a major breakthrough. They made a clever approach to identify the peptide. They worked with autophagy mechanism of cells. Autophagy is a process by which cells can fight off intracellular organisms or digest away protein residues, thereby recycling the contents to keep the cells healthy and disease free. Previous studies on this process identified a protein called beclin-1, an essential autophagy protein in the class III phosphatidylinositol-3-OH kinase (PI(3)K) complex involved in autophagic vesicle nucleation. This protein is a key regulator in inducing autophagy mechanism in cells. Interestingly this protein interacts with HIV-1 virulence factor Nef. Nef is an antiautophagic maturation factor. So the researchers planned to track down the specific site of beclin-1 protein that interacts with nef. They cleverly identified the specific site (267-284aa) by using deletion mutants of beclin-1 protein. Thereafter they used HIV-1 Tat protein transduction domain (PTD) and substituted three amino acids. These modifications made the Tat beclin-1 peptide soluble and easy to go inside cell. [summarized by Muntasir, a graduate student at  Plant Biotech Lab, DU ]