The conserved TREX mRNA export complex is known to contain UAP56, Aly, Tex1, and the THO complex. Here, we carried out proteomic analysis of immunopurified human TREX complex and identified the protein CIP29 as the only new component with a clear yeast relative (known as Tho1). Tho1 is known to function in mRNA export, and we provide evidence that CIP29 likewise functions in this process. Like the known TREX components, a portion of CIP29 localizes in nuclear speckle domains, and its efficient recruitment to mRNA is both splicing- and cap-dependent. We show that UAP56 mediates an ATP-dependent interaction between the THO complex and both CIP29 and Aly, indicating that TREX assembly is ATP-dependent. Using recombinant proteins expressed in Escherichia coli, we show that UAP56, Aly, and CIP29 form an ATP-dependent trimeric complex, and UAP56 bridges the interaction between CIP29 and Aly. We conclude that the interaction of two conserved export proteins, CIP29 and Aly, with UAP56 is strictly regulated by ATP during assembly of the TREX complex.
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http://dx.doi.org/10.1101/gad.1898610 | DOI Listing |
Structure
January 2025
Department of Biochemistry, Vanderbilt University School of Medicine Basic Sciences, Nashville, TN 37232, USA; Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA. Electronic address:
mRNAs are packaged with proteins into messenger ribonucleoprotein complexes (mRNPs) in the nucleus. mRNP assembly and export are of fundamental importance for all eukaryotic gene expression. Before export to the cytoplasm, mRNPs undergo dynamic remodeling governed by the DEAD-box helicase DDX39B (yeast Sub2).
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Program in Neuroscience, Department of Biology, Syracuse University, Syracuse, NY 13210, USA.
Astrocytes produce and export glutathione (GSH), an important thiol antioxidant essential for protecting neural cells from oxidative stress and maintaining optimal brain health. While it has been established that oxidative stress increases GSH production in astrocytes, with Nrf2 acting as a critical transcription factor regulating key components of the GSH synthetic pathway, the role of Nrf2 in controlling constitutive GSH synthetic and release mechanisms remains incompletely investigated. Our data show that naïve primary mouse astrocytes cultured from the cerebral cortices of Nrf2 knockout (Nrf2) pups have significantly less intracellular and extracellular GSH levels when compared to astrocytes cultured from Nrf2 wild-type (Nrf2) pups.
View Article and Find Full Text PDFFront Immunol
January 2025
Immunology Research Center, National Health Research Institute, Zhunan, Taiwan.
CASK, a MAGUK family scaffold protein, regulates gene expression as a transcription co-activator in neurons. However, the mechanism of CASK nucleus translocation and the regulatory function of CASK in myeloid cells remains unclear. Here, we investigated its role in H5N1-infected macrophages.
View Article and Find Full Text PDFAdv Protein Chem Struct Biol
January 2025
Department of Neurochemistry, National Institute of Mental Health and Neuro Sciences Hospital (NIMHANS), Institute of National Importance, Bangalore, Karnataka, India.
Tau is a well-known microtubule-associated protein and is located in the cytoplasm of neurons, which play a crucial role in Alzheimer's diseases. Due to its preferred binding to DNA sequences found in the nucleolus and pericentromeric heterochromatin, Tau has been found within the cell nucleus, where it may be a nucleic acid-associated protein. Tau has the ability to directly interact with nuclear pore complex nucleoporins, influencing both their structural and functional integrity.
View Article and Find Full Text PDFCase Rep Genet
January 2025
Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California, 2825 50th Street, Davis, Sacramento 95817, California, USA.
Fragile X syndrome (FXS) presents with autism spectrum disorder (ASD), intellectual disability, developmental delay, seizures, hypotonia during infancy, joint laxity, behavioral issues, and characteristic facial features. The predominant mechanism is due to CGG trinucleotide repeat expansion of more than 200 repeats in the 5'UTR (untranslated region) of (Fragile X Messenger Ribonucleoprotein 1) causing promoter methylation and transcriptional silencing. However, not all patients presenting with the characteristic phenotype and point/frameshift mutations with deletions in have been described in the literature.
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