influence of posttranslational modifications on proteolysis of peptides - (Nov/05/2010 )

hey,

for those who are familiar with proteases and proteolysis: I'm wondering, if posttranslational modifications have a significant influence on the spcificity of proteases and proteolysis. Does for example phosphorylation of a certain serine or threonine of a small peptide prevent efficient proteolysis of the peptide ? Has the phosphate to be remnoved by phosphatases before ?

Any literature suggestions ?

Markus

The only one I can think of off the top of my head is that ubiquitylation (ubiquitination) is the signal for degradation by the proteasome.