The human epigenetic cell-cycle regulator HCF-1 undergoes an unusual proteolytic maturation process resulting in stably associated HCF-1(N) and HCF-1(C) subunits that regulate different aspects of the cell cycle. Proteolysis occurs at six centrally located HCF-1(PRO)-repeat sequences and is important for activation of HCF-1(C)-subunit functions in M phase progression. We show here that the HCF-1(PRO) repeat is recognized by O-linked β-N-acetylglucosamine transferase (OGT), which both O-GlcNAcylates the HCF-1(N) subunit and directly cleaves the HCF-1(PRO) repeat. Replacement of the HCF-1(PRO) repeats by a heterologous proteolytic cleavage signal promotes HCF-1 proteolysis but fails to activate HCF-1(C)-subunit M phase functions. These results reveal an unexpected role of OGT in HCF-1 proteolytic maturation and an unforeseen nexus between OGT-directed O-GlcNAcylation and proteolytic maturation in HCF-1 cell-cycle regulation.
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http://dx.doi.org/10.1016/j.cell.2010.12.030 | DOI Listing |
Sci Adv
January 2025
Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei, China.
The proteasome degrades most superfluous and damaged proteins, and its decline is associated with many diseases. As the proteolytic unit, the 20 proteasome is assembled from 28 subunits assisted by chaperones PAC1/2/3/4 and POMP; then, it undergoes the maturation process, in which the proteolytic sites are activated and the assembly chaperones are cleared. However, mechanisms governing the maturation remain elusive.
View Article and Find Full Text PDFVaccines (Basel)
November 2024
Laboratory of Proteolytic Enzyme Chemistry, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, 117997 Moscow, Russia.
IgA1 protease is one of the virulence factors of , and other pathogens causing bacterial meningitis. The aim of this research is to create recombinant proteins based on fragments of the mature IgA1 protease A-P from serogroup B strain H44/76. These proteins are potential components of an antimeningococcal vaccine for protection against infections caused by pathogenic strains of and other bacteria producing serine-type IgA1 proteases.
View Article and Find Full Text PDFBiomolecules
December 2024
Inst Neurophysiopathol, CNRS, INP, Aix-Marseille Univ, 13005 Marseille, France.
We previously reported that membrane-type 5-matrix metalloproteinase (MT5-MMP) deficiency not only reduces pathological hallmarks of Alzheimer's disease (AD) in 5xFAD (Tg) mice in vivo but also impairs interleukin-1 beta (IL-1β)-mediated neuroinflammation and Aβ production in primary Tg immature neural cell cultures after 11 days in vitro. We now investigate the effect of MT5-MMP on incipient pathogenic pathways that are activated in cortical primary cultures at 21-24 days in vitro (DIV), during which time neurons are organized into a functional mature network. Using wild-type (WT), MT5-MMP (MT5), 5xFAD (Tg), and 5xFADxMT5-MMP (TgMT5) mice, we generated primary neuronal cultures that were exposed to IL-1β and/or different proteolytic system inhibitors.
View Article and Find Full Text PDFUnlabelled: The maturation of RNA is mediated by the coordinated actions of RNA-binding proteins through post-transcriptional pre-mRNA processing. This process is a central regulatory mechanism for gene expression and plays a crucial role in the development of complex biological systems. MYC directly upregulates transcription of genes encoding the core components of pre-mRNA splicing machinery.
View Article and Find Full Text PDFSubcell Biochem
December 2024
Department of Macromolecular Structure, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain.
Viral genomes are transported between cells using various structural solutions such as spherical or filamentous protein cages, alone or in combination with lipid envelopes, in assemblies of varying complexity. Morphogenesis of the new infectious particles (virions) encompasses capsid assembly from individual components (proteins, and membranes when required), genome packaging, and maturation. This final step is crucial for full infectivity.
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