Mammalian polyamine synthesis is regulated by a unique feedback mechanism. When cellular polyamine levels increase, antizyme, an ornithine decarboxylase (ODC) inhibitory protein, is induced by polyamine-dependent translational frameshifting. Antizyme not only inhibits ODC, a key enzyme in polyamine synthesis, it also targets the enzyme degradation by the 26S proteasome. Furthermore, it suppresses cellular uptake of polyamines. Previously, we isolated two zebrafish antizymes with different expressions and activities. This suggested that a common feedback mechanism of polyamine metabolism might operate in mammals and zebrafish (Danio rerio). In the present study, cDNAs of zebrafish ODC and antizyme inhibitor, another regulatory protein that inhibits antizyme action, were cloned. The presence of ODC and antizyme inhibitor mRNAs was confirmed by Northern blotting in embryos and adult fish, as well as in a zebrafish-derived cell line (BRF41). The activity of the ODC cDNA expression product was inhibited by short and long zebrafish antizymes, and recombinant zebrafish antizyme inhibitor reversed this inhibition. In the BRF41 cells, the ODC half-life was considerably longer than that of mammalian ODC but shorter than that of Schizosaccharomyces pombe. Spermidine elicited a rapid decay of ODC activity and ODC protein in a protein synthesis-dependent manner.
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http://dx.doi.org/10.1016/s0167-4781(02)00476-1 | DOI Listing |
Sci Adv
October 2024
Department of Molecular and Life Science, Hanyang University, Ansan 15588, South Korea.
Front Neurosci
August 2024
Laboratory of Genomic and Precision Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, China.
Introduction: The activation of cerebral endothelial cells (CECs) has recently been reported to be the earliest acute neuroinflammation event in the CNS during sepsis-associated encephalopathy (SAE). Importantly, adenosine-to-inosine (A-to-I) RNA editing mediated by ADARs has been associated with SAE, yet its role in acute neuroinflammation in SAE remains unclear.
Methods: Our current study systematically analyzed A-to-I RNA editing in cerebral vessels, cerebral endothelial cells (CECs), and microglia sampled during acute neuroinflammation after treatment in a lipopolysaccharide (LPS)-induced SAE mouse model.
Cancer Med
August 2024
Department of Hematology, Huadong Hospital Affiliated with Fudan University, Shanghai, China.
Objective: Kidney renal clear cell carcinoma (KIRC, ccRCC) is the most common type of renal cancer with high recurrence and mortality. It has long been recognized that Antizyme inhibitor 1 (AZIN1) serves as a pro-oncogenic molecule in multiple cancers. However, the clinicopathological features of AZIN1 in KIRC remain unexplored.
View Article and Find Full Text PDFJ Clin Invest
September 2024
Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA.
The progression of kidney disease varies among individuals, but a general methodology to quantify disease timelines is lacking. Particularly challenging is the task of determining the potential for recovery from acute kidney injury following various insults. Here, we report that quantitation of post-transcriptional adenosine-to-inosine (A-to-I) RNA editing offers a distinct genome-wide signature, enabling the delineation of disease trajectories in the kidney.
View Article and Find Full Text PDFCells Dev
September 2024
School of Life Science, Bengbu Medical University, Bengbu, Anhui, People's Republic of China. Electronic address:
Undescended testis (UDT), known as cryptorchidism (CRY), is a common congenital disorder in which one or both testicles do not descend normally into the scrotum. A unilateral UDT model was established by inducing UDT in mice through surgery. The results showed that the testis in the UDT model group was abnormal; the lumen of the seminiferous tubule was atrophic; apoptosis, necrosis and shedding were observed in many of the germ cells; the level of sex hormones was abnormal; and mature sperm was reduced.
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