ATLANTA--A cell-piercing protein from the bacterium that causes
tuberculosis (TB) could serve as a delivery system for future
medicines. At the American Society for Microbiology's annual
meeting here researchers reported yesterday that they had
identified a short protein sequence that is key to the TB
bacterium's ability to invade cells. Down the road, the protein
may provide researchers with a powerful new tool to infuse cells
with protein-based drugs and healthy genes for gene therapy.
Cells are normally very selective about what types of compounds
they allow inside. While small molecules such as salt or
carbohydrates readily pass through their membranes, larger
molecules, such as proteins and nucleic acids, are blocked.
Nevertheless, the TB bacterium and other cellular invaders
manage to breach this barrier and force their way inside. Now
researchers at the University of California at Berkeley have
identified a TB protein called Mycobacterium Cell Entry Protein
(MCEP), which pierces cells like a spear and