Publications by authors named "Johanna Virta"

We report the development of a 384-well formatted NanoBRET assay to characterize molecular glues of 14-3-3/client interactions in living cells. The seven isoforms of 14-3-3 are dimeric hub proteins with diverse roles including transcription factor regulation and signal transduction. 14-3-3 interacts with hundreds of client proteins to regulate their function and is therefore an ideal therapeutic target when client selectivity can be achieved.

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Article Synopsis
  • Dysregulation of protein-protein interactions (PPIs) can lead to various diseases, prompting interest in methods to stabilize these interactions for drug discovery, especially with hub proteins like 14-3-3.
  • Researchers employed disulfide tethering, a technique for finding small molecules that can reversibly bond to proteins, to identify selective PPI stabilizers, or "molecular glues," specifically targeting the 14-3-3σ hub protein.
  • Through screening 14-3-3 complexes with five different phosphopeptides, they discovered stabilizing fragments for four of the complexes, with one fragment significantly enhancing the interaction between 14-3-3σ and C-RAF by 430-fold, paving
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Eukaryotes possess eight highly conserved Lsm (like Sm) proteins that assemble into circular, heteroheptameric complexes, bind RNA, and direct a diverse range of biological processes. Among the many essential functions of Lsm proteins, the cytoplasmic Lsm1-7 complex initiates mRNA decay, while the nuclear Lsm2-8 complex acts as a chaperone for U6 spliceosomal RNA. It has been unclear how these complexes perform their distinct functions while differing by only one out of seven subunits.

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U6 snRNA undergoes post-transcriptional 3' end modification prior to incorporation into the active site of spliceosomes. The responsible exoribonuclease is Usb1, which removes nucleotides from the 3' end of U6 and, in humans, leaves a 2',3' cyclic phosphate that is recognized by the Lsm2-8 complex. Saccharomycescerevisiae Usb1 has additional 2',3' cyclic phosphodiesterase (CPDase) activity, which converts the cyclic phosphate into a 3' phosphate group.

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The structure of a 22-base-pair RNA helix with mismatched pyrimidine base pairs is reported. The helix contains two symmetry-related CUG sequences: a triplet-repeat motif implicated in myotonic dystrophy type 1. The CUG repeat contains a U-U mismatch sandwiched between Watson-Crick pairs.

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Background: Several studies show that prostatic fibrosis is associated with male lower urinary tract dysfunction (LUTD). Development of fibrosis is typically attributed to signaling through the transforming growth factor β (TGF-β) pathway, but our laboratory has demonstrated that in vitro treatment of human prostatic fibroblasts with the C-X-C motif chemokine ligand 12 (CXCL12) chemokine stimulates myofibroblast phenoconversion and that CXCL12 has the capacity to activate profibrotic pathways in these cells in a TGF-β-independent manner. We have previously reported that feeding mice high-fat diet (HFD) results in obesity, type II diabetes, increased prostatic fibrosis, and urinary voiding dysfunction.

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