Identification of proteins interacting with GTP cyclohydrolase I.
GTP cyclohydrolase I (GCH-1) is the rate-limiting enzyme in the biosynthesis of tetrahydrobiopterin, an essential cofactor for nitric oxide synthase and aromatic amino acid hydroxylase. To explore the interactome of GCH-1, we established a HEK 293 cell line stably expressing tetracycline-inducible FLAG-GCH-1. FLAG-GCH-1 and associated proteins were immunoprecipitated and analyzed by liquid chromatography/tandem mass spectrometry. Twenty-nine proteins, derived from different subcellular components such as cytosol, membranes, nucleus and mitochondria were identified to interact with GCH-1. Cell fractionation studies also showed that GCH-1 was present in the cytosol, membranes and nucleus. Gene ontology analysis revealed that GCH-1 interactome was involved in a variety of biological processes such as signal transduction, apoptosis, metabolism, transport and cell organization. To our knowledge, this study is the first to provide a comprehensive analysis of the GCH-1 interactome. Findings expand the number and diversity of proteins that are known to associate with GCH-1.
Division of Pediatric Surgery, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
Jianhai
J
Du
Hao
H
Xu
Na
N
Wei
Bassam
B
Wakim
Brian
B
Halligan
Kirkwood A
KA
Pritchard
Yang
Y
Shi
D002458:Cell Fractionation; D002460:Cell Line; D002467:Cell Nucleus / Q000201:enzymology; D002853:Chromatography, Liquid; D003600:Cytosol / Q000201:enzymology; D006136:GTP Cyclohydrolase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008928:Mitochondria / Q000201:enzymology; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D053719:Tandem Mass Spectrometry
D011506:Proteins; D006136:GTP Cyclohydrolase