Discussion
Because desmosomes are responsible for establishing lateral cell-cell junctions, we suggest that direct interaction with the lateral junction protein complex may be implicated in the PLAC1 effects on cell-cell interactions, and thereby on the layer structure of the placenta.
Methods
To investigate the mechanism of action of PLAC1 we did cell fractionation and immunoprecipitation of the protein and Mass Spectrometry analysis to identify its interaction partners. The associated proteins were directly tested for interactions by co-transfection with PLAC1 and immunoprecipitation. Mutations in the ZP-N domain of PLAC1 were introduced to assess its involvement in the interactions.
Results
We provide evidence that Desmoglein-2 (DSG2), a component of the membrane-associated desmosomal complex, directly interacts with PLAC1. Mutations of cysteines in ZP-N domain disrupt the interaction between PLAC1 and DSG-2.