GTPBP4 explained

Nucleolar GTP-binding protein 1 is a protein that in humans is encoded by the GTPBP4 gene.^{[1] [2]}

GTPases function as molecular switches that can flip between two states: active, when GTP is bound, and inactive, when GDP is bound. 'Active' usually means that the molecule acts as a signal to trigger other events in the cell. When an extracellular ligand binds to a G protein-coupled receptor, the receptor changes its conformation and switches on the trimeric G proteins that associate with it by causing them to eject their GDP and replace it with GTP. The switch is turned off when the G protein hydrolyzes its own bound GTP, converting it back to GDP. But before that occurs, the active protein has an opportunity to diffuse away from the receptor and deliver its message for a prolonged period to its downstream target.

Further reading

• Maruyama K, Sugano S . Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides. . Gene . 138 . 1–2 . 171–4 . 1994 . 8125298 . 10.1016/0378-1119(94)90802-8 .
• Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K, etal . Construction and characterization of a full length-enriched and a 5'-end-enriched cDNA library. . Gene . 200 . 1–2 . 149–56 . 1997 . 9373149 . 10.1016/S0378-1119(97)00411-3 .
• Scherl A, Couté Y, Déon C, etal . Functional proteomic analysis of human nucleolus. . Mol. Biol. Cell . 13 . 11 . 4100–9 . 2003 . 12429849 . 10.1091/mbc.E02-05-0271 . 133617 .
• Strausberg RL, Feingold EA, Grouse LH, etal . Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences. . Proc. Natl. Acad. Sci. U.S.A. . 99 . 26 . 16899–903 . 2003 . 12477932 . 10.1073/pnas.242603899 . 139241 . 2002PNAS...9916899M . free .
• Ota T, Suzuki Y, Nishikawa T, etal . Complete sequencing and characterization of 21,243 full-length human cDNAs. . Nat. Genet. . 36 . 1 . 40–5 . 2004 . 14702039 . 10.1038/ng1285 . free .
• Gerhard DS, Wagner L, Feingold EA, etal . The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). . Genome Res. . 14 . 10B . 2121–7 . 2004 . 15489334 . 10.1101/gr.2596504 . 528928 .
• Olsen JV, Blagoev B, Gnad F, etal . Global, in vivo, and site-specific phosphorylation dynamics in signaling networks. . Cell . 127 . 3 . 635–48 . 2006 . 17081983 . 10.1016/j.cell.2006.09.026 . 7827573 . free .
• Lee H, Kim D, Dan HC, etal . Identification and characterization of putative tumor suppressor NGB, a GTP-binding protein that interacts with the neurofibromatosis 2 protein. . Mol. Cell. Biol. . 27 . 6 . 2103–19 . 2007 . 17210637 . 10.1128/MCB.00572-06 . 1820506 .
• Ewing RM, Chu P, Elisma F, etal . Large-scale mapping of human protein-protein interactions by mass spectrometry. . Mol. Syst. Biol. . 3 . 1. 89 . 2007 . 17353931 . 10.1038/msb4100134 . 1847948 .

Notes and References

1. Laping NJ, Olson BA, Zhu Y . Identification of a novel nuclear guanosine triphosphate-binding protein differentially expressed in renal disease . J Am Soc Nephrol . 12 . 5 . 883–90 . Apr 2001 . 10.1681/ASN.V125883 . 11316846 . free .
2. Web site: Entrez Gene: GTPBP4 GTP binding protein 4.