| A screen for proteins that interact with beta 2 syntrophin led to the isolation of MAST 205 ( microtubule associated serine / threonine kinase 205 kD ) and a newly identified homologue , SAST ( syntrophin associated serine / threonine kinase ) . ^^^ Binding studies showed that beta 2 syntrophin and MAST205 / SAST associated via a PDZ PDZ domain interaction . ^^^ |