Proliferating cell nuclear antigen (PCNA) acts as a scaffold, coordinator, and stimulator of numerous processes required for faithful transmission of genetic information. Maintaining PCNA levels above a critical threshold is essential, but little is known about PCNA protein turnover. We now show that ERK8 (extracellular signal-regulated kinase 8) is required for PCNA protein stability. ERK8 contains a conserved PCNA-interacting protein (PIP) box. Chromatin-bound ERK8 (ERK8(CHROMATIN)) interacts via this motif with PCNA(CHROMATIN), which acts as a platform for numerous proteins involved in DNA metabolism. Silencing ERK8 decreases PCNA levels and increases DNA damage. Ectopic expression of PCNA blocks DNA damage induced by ERK8 loss. ERK8 prevents HDM2-mediated PCNA destruction by inhibiting the association of PCNA with HDM2. This regulation is physiologically relevant as ERK8 activity is inhibited in transformed mammary cells. Our results reveal an unanticipated mechanism to control PCNA levels in normal cycling mammary epithelial cells and implicate ERK8 in the regulation of genomic stability.
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http://dx.doi.org/10.1083/jcb.201002124 | DOI Listing |
Arch Dermatol Res
January 2025
School of Public Health, Shanxi Medical University, Taiyuan, China.
Psoriasis is an inflammatory dermatosis that features overproliferation and inflammatory reaction of keratinocytes. A study reported that IL-22 is involved in the pathogenesis of psoriasis by mediating miR-124 to regulate the expression of fibroblast growth factor receptor 2 in keratinocytes. A microRNA may target multiple target genes.
View Article and Find Full Text PDFNaunyn Schmiedebergs Arch Pharmacol
January 2025
Department of Pathology, Faculty of Veterinary Medicine, Alexandria University, Alexandria, 22758, Egypt.
This study investigates the protective effects of resveratrol (RSV) against heat stress (HS)-induced testicular injury in rats. Climate change has exacerbated heat stress, particularly affecting male fertility by impairing testicular function and sexual behavior. A total of 32 rats were allocated into four experimental groups: control, RSV control, HS control, and RSV + HS.
View Article and Find Full Text PDFCurr Med Chem
January 2025
Department of Pediatrics, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, China.
Background: Hyperuricemia (HUA) is a condition characterized by excessive uric acid production and/or inadequate uric acid excretion due to abnormal purine metabolism in the human body. Uric acid deposits resulting from HUA can lead to complications such as renal damage. Currently, drugs used to treat HUA lack specificity and often come with specific toxic side effects.
View Article and Find Full Text PDFPharmaceuticals (Basel)
November 2024
Department of Medical Biochemistry, Faculty of Medicine, Akdeniz University, Antalya 07070, Turkey.
The aim of this study was to determine the effect of Sparstolonin B (SsnB) on cell proliferation and apoptosis in human breast cancer (MCF-7) and human ovarian epithelial cancer (OVCAR-3) cell lines in the presence and absence of estradiol hemihydrate (ES). Phosphoinositol-3 kinase (PI3K), phosphorylated protein kinase B alpha (p-AKT), phosphorylated mTOR (mechanistic target of rapamycin) signaling proteins, and sphingomyelin/ceramide metabolites were also measured within the scope of the study. The anti-proliferative effects of SsnB therapy were evaluated over a range of times and concentrations.
View Article and Find Full Text PDFPoult Sci
December 2024
MOA Key Laboratory of Animal Virology, College of Animal Sciences, Zhejiang University, Hangzhou 310058, PR China; Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, PR China. Electronic address:
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