How multisite posttranslational modification coordinates dynamic regulation of 
protein function is an issue fundamental to many biological processes. Related 
to this, a composite sequence motif has recently been identified that couples 
phosphorylation, sumoylation, and perhaps also deacetylation to control 
transcriptional repression in stress response, mitogen and nuclear hormone 
signaling, myogenesis, and neuronal differentiation. This motif is present in 
many proteins, integrates cellular signals from diverse pathways, and serves as 
a valuable signature for in silico identification of proteins regulated by 
adjacent phosphorylation and sumoylation.