| Thus , we demonstrate : an amphiphysin associated 400 kDa Cdk5 / p25 ( nck5a ) complex , a synapsin 1 associated > 400 kDa Cdk5 / p25 ( nck5a ) complex , and nck5a free Cdk 5 complexes ( 200 to > 400 kDa ) . ^^^ Amphiphysin acts as a Cdk5 / p25 ( nck5a ) substrate in the 400 kDa complex and we speculate that Cdk5 / p25 ( nck5a ) participates in amphiphysin mediated endocytosis . . ^^^ |