Modifier	Substrate	Residue	Sequence	Mechanism/Effect	PMID	Interaction ID
ATR	USP20	–		phosphorylation down-regulates activity	25355518	SIGNOR-278393
ATR	USP20	–		phosphorylation up-regulates quantity by stabilization	25355518	SIGNOR-272822
PRKACA	USP20	Ser333 View in OncoXplorer	RMKDRKFsWGQQRTN	phosphorylation down-regulates quantity by destabilization	25666616	SIGNOR-273795

Enzyme	Effect	Phosphosite	Effect	Target	PMID	Interaction ID
PRKACA	phosphorylation up-regulates →	USP20 PSer333	phosphorylation down-regulates ⊣	USP20	25666616	SIGNOR-273795

Regulator	Mechanism/Effect	Target	SIGNOR-ID
ATR	phosphorylation → down-regulates activity	USP20	SIGNOR-278393
ATR	phosphorylation → up-regulates quantity by stabilization	USP20	SIGNOR-272822
PRKACA	phosphorylation down-regulates quantity by destabilization	USP20	SIGNOR-273795