image: Complex regulation of the profibrotic growth factor TGFbeta by microfibrils (composed of the protein fibrillin-1). In normal tissues, microfibrils serve to concentrate TGFbeta and to negatively regulate its activation. The level of TGFbeta activity (indicated by the size of the starburst) integrates these two functions. In Marfan syndrome, a deficiency of microfibrils leads to decreased TGFbeta concentration that is offset by increased activation. Integrins (subunits labeled alpha and beta) that are not occupied by microfibrils may be more available to participate in TGFbeta activation. In stiff skin syndrome, increased deposition of microfibrils that fail to interact with integrins leads to increased TGFbeta concentration (and perhaps activation) and signaling. This image relates to an article that appeared in the 17 March 2010 issue of Science Translational Medicine. The study, by Dr. Bart Loeys of Howard Hughes Medical Institutes and Johns Hopkins University in Baltimore, and colleagues was titled, "Mutations in Fibrillin-1 Cause Congenital Scleroderma: Stiff Skin Syndrome." view more
Credit: [Image courtesy of <i>Science</i>/AAAS]