and shoulder muscle tissues, but the decrease will be to a lesser extent. If these results are to occur, identification of the binding protein is needed via sequencing methods (ie. Edman degradation). A prediction is that the protein binds to the poly-A stretches for normal functioning of PABP2, perhaps assisting it to act as a factor in mRNA polyadenylation. In affected tissues, some of these binding proteins may not be able to recognize the extended repeats thus decreasing PABP2's function. Under these results, the hypothesis would be rejected.For the yeast-two-hybrid experiments, blue colonies will signify the binding of proteins to the different forms of PABP2. If blue colonies appear for tests with the gene encoding for mutant PABP2s, it will indicate an acceptance of the hypothesis. These positive clones will need to be analyzed further by restriction analysis, PCR, or by sequencing. These analytical methods will show if the same protein binds to all forms of the mutant or if different proteins bind to the varying mutant forms. The proteins that bind to PABP2 may bind specifically to the poly-A stretches or to other sites of PABP2. This system, however, cannot distinguish these two possibilities.On the other hand, if no colonies appear blue for tests with mutant PABP2s, there are no proteins that bind to them. This result will help reject the hypothesis. It may also show that the lack of binding to a particular protein specific for wild-type PABP2 results in the disease. In this case, blue colonies will need to appear when the gene that is fused to the gene encoding for Gal4 BD is the wild-type form of PABP2. CONCLUSION:These binding experiments will greatly enhance the understanding of OPMD. They will find potential proteins which act downstream of the mutated PABP2, causing the continual disintegration of muscle tissue over time. Indeed, as mentioned before, sequencing, PCR, or restriction analysis of the elucidat...
