Polycomb group (PcG) and trithorax group (trxG) proteins are well known for their role in the maintenance of silent and active expression states of homeotic genes. However, PcG proteins may also be required for the control of cellular proliferation in vertebrates. In Drosophila, PcG factors act by associating with specific DNA regions termed PcG response elements (PREs). Here, we have investigated whether Drosophila cell cycle genes are directly regulated by PcG proteins through PREs. We have isolated a PRE that regulates Cyclin A (CycA) expression. This sequence is bound by the Polycomb (PC) and Polyhomeotic (PH) proteins of the PcG, and also by GAGA factor (GAF), a trxG protein that is usually found associated with PREs. This sequence causes PcG- and trxG-dependent variegation of the mini-white reporter gene in transgenic flies. The combination of FISH with PC immunostaining in embryonic cells shows that the endogenous CycA gene colocalizes with PC at foci of high PC concentration named PcG bodies. Finally, loss of function of the Pc gene and overexpression of Pc and ph trigger up-regulation and down-regulation, respectively, of CycA expression in embryos. These results demonstrate that CycA is directly regulated by PcG proteins, linking them to cell cycle control in vivo.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1369051 | PMC |
| http://dx.doi.org/10.1101/gad.357106 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Molecular Mechanisms of Grain Chalkiness Variation in Rice Panicles.
Plants (Basel)
January 2025
Rice Research Institute, Anhui Academy of Agricultural Sciences, Hefei 230031, China.
Grain chalkiness adversely affects rice quality, and the positional variation of grain chalkiness within a rice panicle presents a substantial obstacle to quality improvement in China. However, the molecular mechanism underlying this variation is unclear. This study conducted a genetic and physiological analysis of grains situated at distinct positions (upper, middle, and bottom primary branches of the rice panicle, denoted as Y1, Y2, and Y3) within a rice panicle using the Yangdao 6 variety.
View Article and Find Full Text PDFAlternative silencing states of transposable elements in Arabidopsis associated with H3K27me3.
Genome Biol
January 2025
Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, Centre National de La Recherche Scientifique (CNRS), Commissariat À L'EnergieAtomique (CEA), Gif-Sur-Yvette, 91190, France.
Background: The DNA/H3K9 methylation and Polycomb-group proteins (PcG)-H3K27me3 silencing pathways have long been considered mutually exclusive and specific to transposable elements (TEs) and genes, respectively in mammals, plants, and fungi. However, H3K27me3 can be recruited to many TEs in the absence of DNA/H3K9 methylation machinery and sometimes also co-occur with DNA methylation.
Results: In this study, we show that TEs can also be solely targeted and silenced by H3K27me3 in wild-type Arabidopsis plants.
Insights Into the Role of Bmi-1 Deregulation in Promoting Stemness and Therapy Resistance in Glioblastoma: A Narrative Review.
Cancer Med
January 2025
Faculty of Medical Sciences, Neuroscience Research Center, Lebanese University, Hadath, Lebanon.
Background: Glioblastoma (GBM) is the most common primary brain tumor in adults and has a median survival of less than 15 months. Advancements in the field of epigenetics have expanded our understanding of cancer biology and helped explain the molecular heterogeneity of these tumors. B-cell-specific Moloney murine leukemia virus insertion site-1 (Bmi-1) is a member of the highly conserved polycomb group (PcG) protein family that acts as a transcriptional repressor of multiple genes, including those that determine cell proliferation and differentiation.
View Article and Find Full Text PDFFunctional genomics of primary congenital glaucoma by pathway analysis and functional characterization of CYP1B1 mutations.
Vision Res
December 2024
Medical Biotechnology Laboratory, Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi 110007, India. Electronic address:
CYP1B1 is the most common gene implicated in primary congenital glaucoma (PCG) - the most common form of childhood glaucoma. How CYP1B1 mutations cause PCG is not known. Understanding the mechanism of PCG caused by CYP1B1 mutations is crucial for disease management, therapeutics development, and potential prevention.
View Article and Find Full Text PDFEvolutionary Nonindependence Between Human piRNAs and Their Potential Target Sites in Protein-Coding Genes.
J Mol Evol
December 2024
Bioinformatics Section, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
Article Synopsis
- piRNAs are diverse small RNAs that help suppress transposable elements and are linked to protein-coding genes (PCGs) in the human genome.
- This study utilized statistical analyses to show that there are nonrandom evolutionary forces influencing the relationships between piRNAs and their target PCGs, indicating a bias toward strengthening these connections.
- Additionally, the research found that potential piRNA target sites are often located in Alu-derived regions of PCGs, highlighting the specific impact of these evolutionary forces on certain genomic areas.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!