Kinase, in vitro: 

An enzyme-substrate reaction that occurs in non-living experimental conditions such as a test tube. For example, a purified enzyme is reacted with a substrate protein or mixture of proteins or peptides.

PAK3 S154-p
Putative upstream phosphatases:
PPP1CA S154-p , T436-p
PPP2CA S154-p , T436-p
PPP2CB S154-p
Regulatory protein:
CDK15 S154-p
FRAX486 S154-p
insulin S186-p , S220-p