Ubiquitination and filamentous structure of cytidine triphosphate synthase.
Living organisms respond to nutrient availability by regulating the activity of metabolic enzymes. Therefore, the reversible post-translational modification of an enzyme is a common regulatory mechanism for energy conservation. Recently, cytidine-5'-triphosphate (CTP) synthase was discovered to form a filamentous structure that is evolutionarily conserved from flies to humans. Interestingly, induction of the formation of CTP synthase filament is responsive to starvation or glutamine depletion. However, the biological roles of this structure remain elusive. We have recently shown that ubiquitination regulates CTP synthase activity by promoting filament formation in Drosophila ovaries during endocycles. Intriguingly, although the ubiquitination process was required for filament formation induced by glutamine depletion, CTP synthase ubiquitination was found to be inversely correlated with filament formation in Drosophila and human cell lines. In this article, we discuss the putative dual roles of ubiquitination, as well as its physiological implications, in the regulation of CTP synthase structure.
a Department of Biochemistry , Chang Gung University , Taoyuan City , Taiwan.|b Molecular Medicine Research Center, Chang Gung University , Taoyuan City , Taiwan.|c Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University , Taoyuan City , Taiwan.|d Liver Research Center, Chang Gung Memorial Hospital , Taoyuan City , Taiwan.
Li-Mei
LM
Pai
a Department of Biochemistry , Chang Gung University , Taoyuan City , Taiwan.|b Molecular Medicine Research Center, Chang Gung University , Taoyuan City , Taiwan.
Pei-Yu
PY
Wang
b Molecular Medicine Research Center, Chang Gung University , Taoyuan City , Taiwan.
Wei-Cheng
WC
Lin
c Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University , Taoyuan City , Taiwan.
Archan
A
Chakraborty
c Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University , Taoyuan City , Taiwan.|d Liver Research Center, Chang Gung Memorial Hospital , Taoyuan City , Taiwan.
Chau-Ting
CT
Yeh
c Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University , Taoyuan City , Taiwan.
Yu-Hung
YH
Lin
D000818:Animals; D019731:Carbon-Nitrogen Ligases / Q000737:chemistry* / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism; D004330:Drosophila / Q000201:enzymology*; D005260:Female; D005973:Glutamine / Q000378:metabolism; D010053:Ovary / Q000201:enzymology; D011499:Protein Processing, Post-Translational; D054875:Ubiquitination
D005973:Glutamine; D019731:Carbon-Nitrogen Ligases; C019951:CTP synthetase
CTP synthase; Cbl; Drosophila; Ubiquitination; cytoophidia; endocycle