Key role of uridine kinase and uridine phosphorylase in the homeostatic regulation of purine and pyrimidine salvage in brain

2007 ◽  
Vol 51 (8) ◽  
pp. 517-523 ◽  
Author(s):  
Francesco Balestri ◽  
Catia Barsotti ◽  
Ludovico Lutzemberger ◽  
Marcella Camici ◽  
Piero Luigi Ipata
Keyword(s):  
Homeostatic Regulation ◽  
Uridine Phosphorylase ◽  
Uridine Kinase ◽  
Pyrimidine Salvage

scholarly journals Smooth muscle-specific HuR knockout induces defective autophagy and atherosclerosis

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Shanshan Liu ◽  
Xiuxin Jiang ◽  
Xiuru Cui ◽  
Jingjing Wang ◽  
Shangming Liu ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Cardiovascular Events ◽  
Rna Binding ◽  
Rna Binding Protein ◽  
Plaque Burden ◽  
Atherosclerotic Plaques ◽  
Ampk Activation ◽  
Homeostatic Regulation ◽  
Human Antigen R

AbstractHuman antigen R (HuR) is a widespread RNA-binding protein involved in homeostatic regulation and pathological processes in many diseases. Atherosclerosis is the leading cause of cardiovascular disease and acute cardiovascular events. However, the role of HuR in atherosclerosis remains unknown. In this study, mice with smooth muscle-specific HuR knockout (HuRSMKO) were generated to investigate the role of HuR in atherosclerosis. HuR expression was reduced in atherosclerotic plaques. As compared with controls, HuRSMKO mice showed increased plaque burden in the atherosclerotic model. Mechanically, HuR could bind to the mRNAs of adenosine 5′-monophosphate-activated protein kinase (AMPK) α1 and AMPKα2, thus increasing their stability and translation. HuR deficiency reduced p-AMPK and LC3II levels and increased p62 level, thereby resulting in defective autophagy. Finally, pharmacological AMPK activation induced autophagy and suppressed atherosclerosis in HuRSMKO mice. Our findings suggest that smooth muscle HuR has a protective effect against atherosclerosis by increasing AMPK-mediated autophagy.

High-synconformation of uridine and asymmetry of the hexameric molecule revealed in the high-resolution structures ofShewanella oneidensisMR-1 uridine phosphorylase in the free form and in complex with uridine

2014 ◽  
Vol 70 (12) ◽  
pp. 3310-3319 ◽  
Author(s):  
Tatyana N. Safonova ◽  
Sergey N. Mikhailov ◽  
Vladimir P. Veiko ◽  
Nadezhda N. Mordkovich ◽  
Valentin A. Manuvera ◽  
...  
Keyword(s):  
High Resolution ◽  
Active Sites ◽  
Shewanella Oneidensis ◽  
Free Form ◽  
Uridine Phosphorylase ◽  
Glycerol Molecule ◽  
Closed Conformation ◽  
Pyrimidine Salvage ◽  
Key Enzyme ◽  
Crystallization Solution

Uridine phosphorylase (UP; EC 2.4.2.3), a key enzyme in the pyrimidine-salvage pathway, catalyzes the reversible phosphorolysis of uridine to uracil and ribose 1-phosphate. Expression of UP fromShewanella oneidensisMR-1 (SoUP) was performed inEscherichia coli. The high-resolution X-ray structure of SoUP was solved in the free form and in complex with uridine. A crystal of SoUP in the free form was grown under microgravity and diffracted to ultrahigh resolution. Both forms of SoUP contained sulfate instead of phosphate in the active site owing to the presence of ammonium sulfate in the crystallization solution. The latter can be considered as a good mimic of phosphate. In the complex, uridine adopts a high-synconformation with a nearly planar ribose ring and is present only in one subunit of the hexamer. A comparison of the structures of SoUP in the free form and in complex with the natural substrate uridine showed that the subunits of the hexamer are not identical, with the active sites having either an open or a closed conformation. In the monomers with the closed conformation, the active sites in which uridine is absent contain a glycerol molecule mimicking the ribose moiety of uridine.

scholarly journals Borrelia burgdorferi uridine kinase: an enzyme of the pyrimidine salvage pathway for endogenous use of nucleotides

2006 ◽  
Vol 151 (2) ◽  
pp. 257-261 ◽  
Author(s):  
C Boursaux-Eude ◽  
D Margarita ◽  
A.M Gilles ◽  
O Bârzu ◽  
I Saint Girons
Keyword(s):  
Borrelia Burgdorferi ◽  
Salvage Pathway ◽  
Uridine Kinase ◽  
Pyrimidine Salvage

6.18 The Role of The Liver in the Metabolism of Manganese and Copper

1983 ◽  
Vol 7 ◽  
pp. 153-153
Author(s):  
H. W. Symonds ◽  
Lynne L. Charmley
Keyword(s):  
Trace Elements ◽  
Homeostatic Regulation ◽  
Hepatic Portal ◽  
Carotid Vessels

The liver is important in the homeostatic regulation of manganese (Mn) and copper (Cu). The rates at which the liver removes these trace elements from plasma and excretes them in bile have been measured by using either cattle in which the duodenum had been surgically modified to allow bile to be sampled and its rate of flow measured, or cattle with cannulae in hepatic, portal, mesenteric and carotid vessels.

Modelling the homeostatic regulation of the sleep-wake cycle: role of diversity

2014 ◽  
Vol 1 ◽  
pp. 365-368
Author(s):  
M. Patriarca ◽  
S. Postnova ◽  
H.A. Braun ◽  
E. Hernández-García ◽  
R. Toral
Keyword(s):  
Homeostatic Regulation

scholarly journals Essential Role of Dopamine D2 Receptor in the Maintenance of Wakefulness, But Not in Homeostatic Regulation of Sleep, in Mice

2010 ◽  
Vol 30 (12) ◽  
pp. 4382-4389 ◽  
Author(s):  
W.-M. Qu ◽  
X.-H. Xu ◽  
M.-M. Yan ◽  
Y.-Q. Wang ◽  
Y. Urade ◽  
...  
Keyword(s):  
Essential Role ◽  
Dopamine D2 Receptor ◽  
D2 Receptor ◽  
Homeostatic Regulation ◽  
Dopamine D2

scholarly journals Pyrimidine Nucleoside Salvage Confers an Advantage to Xenorhabdus nematophila in Its Host Interactions

2005 ◽  
Vol 71 (10) ◽  
pp. 6254-6259 ◽  
Author(s):  
Samantha S. Orchard ◽  
Heidi Goodrich-Blair
Keyword(s):  
Manduca Sexta ◽  
Entomopathogenic Nematodes ◽  
Xenorhabdus Nematophila ◽  
Wild Type ◽  
Pyrimidine Nucleoside ◽  
Host Interactions ◽  
Mutant Strains ◽  
Pyrimidine Salvage ◽  
Nucleoside Salvage

ABSTRACT Xenorhabdus nematophila is a mutualist of entomopathogenic nematodes and a pathogen of insects. To begin to examine the role of pyrimidine salvage in nutrient exchange between X. nematophila and its hosts, we identified and mutated an X. nematophila tdk homologue. X. nematophila tdk mutant strains had reduced virulence toward Manduca sexta insects and a competitive defect for nematode colonization in plate-based assays. Provision of a wild-type tdk allele in trans corrected the defects of the mutant strain. As in Escherichia coli, X. nematophila tdk encodes a deoxythymidine kinase, which converts salvaged deoxythymidine and deoxyuridine nucleosides to their respective nucleotide forms. Thus, nucleoside salvage may confer a competitive advantage to X. nematophila in the nematode intestine and be important for normal entomopathogenicity.

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