RNA-Binding Protein MSI2 Binds to miR-301a-3p and Facilitates Its Distribution in Mitochondria of Endothelial Cells

Numerous miRNAs have been detected in mitochondria, which play important roles in many physiological and pathophysiological processes. However, the dynamic changes of miRNA distribution in mitochondria and their mechanisms in reactive oxygen species (ROS)-induced endothelial injury remain unclear. Therefore, miRNA levels in whole cells and mitochondria of H2O2-treated endothelial cells were analyzed by small RNA sequencing in the present study. The results showed that H2O2 significantly reduced the relative mitochondrial distribution of dozens of miRNAs in human umbilical vein endothelial cells (HUVECs). Among the high-abundance miRNAs, miR-301a-3p has the most significant changes in the redistribution between cytosol and mitochondria confirmed by absolute quantitative polymerase chain reaction (qPCR). To unravel the mechanism of miR-301a-3p distribution in mitochondria, RNA pull-down followed by label-free quantitative proteomic analysis was performed, and RNA-binding protein Musashi RNA binding protein 2 (MSI2) was found to specifically bind to miR-301a-3p. Western blotting and immunofluorescence colocalization assay showed that MSI2 was located in mitochondria of various cell types. H2O2 significantly downregulated MSI2 expression in whole endothelial cells, promoted the distribution of MSI2 in cytosol and decreased its distribution in the mitochondria. Moreover, overexpression of MSI2 increased the mitochondrial distribution of miR-301a-3p, whereas inhibition of MSI2 decreased its distribution in mitochondria. Thus, MSI2 might be responsible for the distribution of miR-301a-3p between cytosol and mitochondria in endothelial cells. Our findings revealed for the first time that MSI2 was involved in the regulation of miRNA distribution in mitochondria and provided valuable insight into the mechanism of mitochondrial distribution of miRNAs.

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Small RNA sequencing of Potato leafroll virus-infected plants reveals an additional subgenomic RNA encoding a sequence-specific RNA-binding protein

Virology ◽

10.1016/j.virol.2012.12.012 ◽

2013 ◽

Vol 438 (2) ◽

pp. 61-69 ◽

Cited By ~ 16

Author(s):

Yeen Ting Hwang ◽

Melanie Kalischuk ◽

Adriana F. Fusaro ◽

Peter M. Waterhouse ◽

Lawrence Kawchuk

Keyword(s):

Rna Sequencing ◽

Small Rna ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Potato Leafroll Virus ◽

Small Rna Sequencing ◽

Subgenomic Rna ◽

Leafroll Virus

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SR-Like RNA-Binding Protein Slr1 Affects Candida albicans Filamentation and Virulence

Infection and Immunity ◽

10.1128/iai.00864-12 ◽

2013 ◽

Vol 81 (4) ◽

pp. 1267-1276 ◽

Cited By ~ 26

Author(s):

Chaiyaboot Ariyachet ◽

Norma V. Solis ◽

Yaoping Liu ◽

Nemani V. Prasadarao ◽

Scott G. Filler ◽

...

Keyword(s):

Endothelial Cells ◽

Candida Albicans ◽

Rna Binding ◽

Rna Binding Proteins ◽

Binding Protein ◽

Umbilical Vein ◽

Polarized Growth ◽

Content Type ◽

Fungal Burden

ABSTRACTCandida albicanscauses both mucosal and disseminated infections, and its capacity to grow as both yeast and hyphae is a key virulence factor. Hyphal formation is a type of polarized growth, and members of the SR (serine-arginine) family of RNA-binding proteins influence polarized growth of bothSaccharomyces cerevisiaeandAspergillus nidulans. Therefore, we investigated whether SR-like proteins affect filamentous growth and virulence ofC. albicans. BLAST searches withS. cerevisiaeSR-like protein Npl3 (ScNpl3) identified twoC. albicansproteins: CaNpl3, an apparent ScNpl3 ortholog, and Slr1, anotherSR-likeRNA-binding protein with no closeS. cerevisiaeortholog. Whereas ScNpl3 was critical for growth, deletion ofNPL3inC. albicansresulted in few phenotypic changes. In contrast, theslr1Δ/Δ mutant had a reduced growth ratein vitro, decreased filamentation, and impaired capacity to damage epithelial and endothelial cellsin vitro. Mice infected intravenously with theslr1Δ/Δ mutant strain had significantly prolonged survival compared to that of mice infected with the wild-type orslr1Δ/Δ mutant complemented withSLR1(slr1Δ/Δ+SLR1) strain, without a concomitant decrease in kidney fungal burden. Histopathology, however, revealed differential localization ofslr1Δ/Δ hyphal and yeast morphologies within the kidney. Mice infected withslr1Δ/Δ cells also had an increased brain fungal burden, which correlated with increased invasion of brain, but not umbilical vein, endothelial cellsin vitro. The enhanced brain endothelial cell invasion was likely due to the increased surface exposure of the Als3 adhesin onslr1Δ/Δ cells. Our results indicate that Slr1 is an SR-like protein that influencesC. albicansgrowth, filamentation, host cell interactions, and virulence.

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An endogenous PI3K interactome promoting astrocyte mediated neuroprotection identifies a novel association with RNA binding protein ZC3H14

Journal of Biological Chemistry ◽

10.1074/jbc.ra120.015389 ◽

2020 ◽

pp. jbc.RA120.015389

Author(s):

Samih Alqawlaq ◽

Izhar Livne-Bar ◽

Declan Williams ◽

Joseph D'Ercole ◽

Sara W. Leung ◽

...

Keyword(s):

Cortical Neurons ◽

Kinase Inhibitors ◽

Rna Binding ◽

Ganglion Cells ◽

Binding Protein ◽

Neuronal Cells ◽

Rna Binding Protein ◽

Neuroprotective Activity ◽

Valuable Insight ◽

Complex Activity

Astrocytes can support neuronal survival through a range of secreted signals that protect against neurotoxicity, oxidative stress, and apoptotic cascades. Thus, analyzing the effects of the astrocyte secretome may provide valuable insight into these neuroprotective mechanisms. Previously, we characterized a potent neuroprotective activity mediated by retinal astrocyte conditioned media (ACM) on retinal and cortical neurons in metabolic stress models. However, the molecular mechanism underlying this complex activity in neuronal cells has remained unclear. Here, a chemical genetics screen of kinase inhibitors revealed phosphoinositide 3-kinase (PI3K) as a central player transducing ACM-mediated neuroprotection. To identify additional proteins contributing to the protective cascade, endogenous PI3K was immunoprecipitated from neuronal cells exposed to ACM or control media, followed by MS/MS proteomic analyses. These data pointed toward a relatively small number of proteins that co-immunoprecipitated with PI3K, and surprisingly only five were regulated by the ACM signal. These hits included expected PI3K interactors, such as the platelet-derived growth factor receptor A (PDGFRA), as well as novel RNA binding protein (RBP) interactors ZC3H14 (zinc finger CCCH-type containing 14) and THOC1 (THO complex protein 1). In particular, ZC3H14 has recently emerged as an important RBP with multiple roles in post-transcriptional regulation. In validation studies, we show that PI3K recruitment of ZC3H14 is necessary for PDGF-induced neuroprotection, and that this interaction is present in primary retinal ganglion cells. Thus, we identified a novel non-cell autonomous neuroprotective signaling cascade mediated through PI3K that requires recruitment of ZC3H14 and may present a promising strategy to promote astrocyte-secreted pro-survival signals.

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