Project Summary The primary goal of this Program Project is to understand the molecular mechanisms by which the physiological and pathophysiological functions of integrins are regulated in blood and vascular cells. The “Protein Expression and Purification” Core B will assist each of the three projects realize this common goal by providing the proteins and cDNAs needed to analyze these molecular mechanisms. The proteins needed by the projects of the program are integrins, talin, kindlins, IRAK1, paxillin, and fragments of these proteins. The cDNAs needed are for expression of the integrins, talin, paxillin, kindlins, and IRAK1, mutant forms of and fragments of these proteins. By providing well-characterized proteins and cDNAs, this core creates reliable reagents that are useful to all three Projects of the Program. To address the structure-function relationships proposed in each project of the program requires substantial amounts of the wild-type and mutant forms of the target proteins. Both bacterial and mammalian expression of proteins is needed. The centralization of protein expression and mutagenesis avoids unneeded replication of procedures within individual laboratories, provides access to equipment that is needed for protein expression and purification, and allows these tasks to be performed efficiently and economically by experienced personnel. There is also a training element to Core B. The Core personnel will train fellows and technical staff within the individual projects to perform protein purification, bacterial and mammalian expression, mutagenesis strategies and in protein characterization approaches.