3.5.4.16	additional information	ubiquitination and proteasome-dependent degradation of GCH1. The CHIP-ubiquitin pathway modifies GCH1 in a lamb model of pulmonary hypertension secondary to increased pulmonary blood flow	718553	
3.5.4.16	phosphoprotein	GCH-1 has 8 potential phosphorylation sites (Ser51, Ser72, Thr85, Thr91, Thr103, Ser130, Ser167, and Thr231). Overexpressed rat GCH-1 is phosphorylated at Ser51, Ser167, and Thr231 in HEK-293 cells	711040	
3.5.4.16	phosphoprotein	S81 phosphorylation enhances GTPCH-1 enzyme activity, GFRP modulates phosphorylation of GTPCH-1, and GTPCH-1 phosphorylation reduces its binding to GFRP, overview	719308