scholarly journals CUS2, a Yeast Homolog of Human Tat-SF1, Rescues Function of Misfolded U2 through an Unusual RNA Recognition Motif

1998 ◽  
Vol 18 (9) ◽  
pp. 5000-5009 ◽  
Author(s):  
Dong Yan ◽  
Rhonda Perriman ◽  
Haller Igel ◽  
Kenneth J. Howe ◽  
Megan Neville ◽  
...  
Keyword(s):  
Rna Binding ◽  
Rna Binding Proteins ◽  
Normal Activity ◽  
Binding Activity ◽  
Rna Recognition Motif ◽  
Rna Recognition ◽  
Recognition Motif ◽  
Yeast Homolog

ABSTRACT A screen for suppressors of a U2 snRNA mutation identified CUS2, an atypical member of the RNA recognition motif (RRM) family of RNA binding proteins. CUS2 protein is associated with U2 RNA in splicing extracts and interacts with PRP11, a subunit of the conserved splicing factor SF3a. Absence of CUS2 renders certain U2 RNA folding mutants lethal, arguing that a normal activity of CUS2 is to help refold U2 into a structure favorable for its binding to SF3b and SF3a prior to spliceosome assembly. Both CUS2 function in vivo and the in vitro RNA binding activity of CUS2 are disrupted by mutation of the first RRM, suggesting that rescue of misfolded U2 involves the direct binding of CUS2. Human Tat-SF1, reported to stimulate Tat-specific, transactivating region-dependent human immunodeficiency virus transcription in vitro, is structurally similar to CUS2. Anti-Tat-SF1 antibodies coimmunoprecipitate SF3a66 (SAP62), the human homolog of PRP11, suggesting that Tat-SF1 has a parallel function in splicing in human cells.

TLS (FUS) binds RNA in vivo and engages in nucleo-cytoplasmic shuttling

1997 ◽  
Vol 110 (15) ◽  
pp. 1741-1750 ◽  
Author(s):  
H. Zinszner ◽  
J. Sok ◽  
D. Immanuel ◽  
Y. Yin ◽  
D. Ron
Keyword(s):  
Rna Binding ◽  
Cellular Transformation ◽  
Rna Recognition Motif ◽  
Rna Recognition ◽  
Nucleocytoplasmic Shuttling ◽  
Uv Crosslinking ◽  
Recognition Motif ◽  
Specific Analysis ◽  
Human And Mouse

TLS, the product of a gene commonly translocated in liposarcomas (TLS), is prototypical of a newly identified class of nuclear proteins that contain a C-terminal domain with a distinct RNA recognition motif (RRM) surrounded by Arg-Gly-Gly (RGG) repeats. Its unique N terminus serves as an essential transforming domain for a number of fusion oncoproteins in human sarcomas and leukemias. In this study we use an in vivo UV crosslinking procedure to probe the interactions of TLS with RNA. TLS is found to bind RNA in vivo and the association of TLS with RNA is rapidly diminished by treating cells with transcriptional inhibitors. This suggests that the species bound by TLS turns over rapidly. Surprisingly, the RRM was found to be dispensable for RNA binding by TLS in vivo, suggesting that at any one time most of the interactions between TLS and RNA in the cell are not sequence specific. Analysis of inter specific heterokaryons formed between human and mouse or Xenopus cells revealed that TLS engages in rapid nucleocytoplasmic shuttling, a finding confirmed by the ability of anti-TLS antibodies to trap TLS when injected into the cytoplasm of HeLa cells. Cellular fractionation experiments suggest that TLS binds to RNA in both the nucleus and cytoplasm and support the hypothesis that TLS functions as a heterogeneous ribonuclear protein (hnRNP)-like chaperone of RNA. These findings are discussed in the context of the role altered forms of TLS play in cellular transformation.

scholarly journals Engineered Exosomes for the Targeted Delivery of a Novel Therapeutic Cargo to Enhance Sorafenib-Mediated Ferroptosis in Hepatocellular Carcinoma.

2021 ◽  
Author(s):  
Xiaoju Li ◽  
Qianqian Yu ◽  
Xinyan Guo ◽  
Chenlin Liu ◽  
Runze Zhao ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Targeted Delivery ◽  
Rna Recognition Motif ◽  
Advanced Hepatocellular Carcinoma ◽  
Rna Recognition ◽  
Sorafenib Treatment ◽  
Recognition Motif ◽  
Interfering Rna

Abstract Background Sorafenib is one of the few effective first-line drugs approved for the treatment of advanced hepatocellular carcinoma (HCC). However, the development of drug resistance is common among individuals with HCC. Thus, there is an urgent need to solve this problem. Results Recent evidence indicated that the anticancer activity of sorafenib mainly relies on the induction of ferroptosis. In our study, genes that suppress ferroptosis, especially GPX4 and DHODH, were enriched in sorafenib-resistant cells and primary tissues and were associated with poor prognosis of HCC patients who received sorafenib treatment. Therefore, silencing GPX4 and DHODH might be a novel and effective strategy to overcome sorafenib resistance. Here, a novel ferroptosis inducer comprising a multiplex small interfering RNA (multi-siRNA) capable of simultaneously silencing GPX4 and DHODH was created. Then, exosomes with high multi-siRNA loading and HCC-specific targeting were established by fusing the SP94 peptide and the N-terminal RNA recognition motif (RRM) of U1-A with the exosomal membrane protein Lamp2b. The results from the in vitro and in vivo experiments indicate that this tumor-targeting nanodelivery system (ExoSP94−lamp2b−RRM-multi-siRNA) could enhance sorafenib-induced ferroptosis and overcome sorafenib resistance, which might open a new avenue for clinically overcoming sorafenib resistance. Conclusions We designed HCC-targeted exosomes (ExoSP94−Lamp2b−RRM) that can deliver a novel ferroptosis inducer. Our data show that ExoSP94−lamp2b−RRM-multi-siRNA could enhance sorafenib-induced ferroptosis by silencing GPX4 and DHODH expression and consequently increase HCC sensitivity to sorafenib. This is the first study to describe the use of engineered exosomes to overcome acquired sorafenib resistance with respect to ferroptosis.

scholarly journals Prediction of tertiary structure of NSSRs’ RNA recognition motif and the RNA binding activity

2005 ◽  
Vol 6 (5) ◽  
pp. 475-483 ◽  
Author(s):  
Kazuo Fushimi ◽  
Shizuka Uchida ◽  
Ryousuke Matsushita ◽  
Toshifumi Tsukahara
Keyword(s):  
Rna Binding ◽  
Tertiary Structure ◽  
Binding Activity ◽  
Rna Recognition Motif ◽  
Rna Recognition ◽  
Recognition Motif

scholarly journals RNA-recognition motif in Matrin-3 mediates neurodegeneration through interaction with hnRNPM

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Nandini Ramesh ◽  
Sukhleen Kour ◽  
Eric N. Anderson ◽  
Dhivyaa Rajasundaram ◽  
Udai Bhan Pandey
Keyword(s):  
Motor Neurons ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Rna Recognition Motif ◽  
Rna Recognition ◽  
Dependent Manner ◽  
Recognition Motif ◽  
Matrin 3

Abstract Background Amyotrophic lateral sclerosis (ALS) is an adult-onset, fatal neurodegenerative disease characterized by progressive loss of upper and lower motor neurons. While pathogenic mutations in the DNA/RNA-binding protein Matrin-3 (MATR3) are linked to ALS and distal myopathy, the molecular mechanisms underlying MATR3-mediated neuromuscular degeneration remain unclear. Methods We generated Drosophila lines with transgenic insertion of human MATR3 wildtype, disease-associated variants F115C and S85C, and deletion variants in functional domains, ΔRRM1, ΔRRM2, ΔZNF1 and ΔZNF2. We utilized genetic, behavioral and biochemical tools for comprehensive characterization of our models in vivo and in vitro. Additionally, we employed in silico approaches to find transcriptomic targets of MATR3 and hnRNPM from publicly available eCLIP datasets. Results We found that targeted expression of MATR3 in Drosophila muscles or motor neurons shorten lifespan and produces progressive motor defects, muscle degeneration and atrophy. Strikingly, deletion of its RNA-recognition motif (RRM2) mitigates MATR3 toxicity. We identified rump, the Drosophila homolog of human RNA-binding protein hnRNPM, as a modifier of mutant MATR3 toxicity in vivo. Interestingly, hnRNPM physically and functionally interacts with MATR3 in an RNA-dependent manner in mammalian cells. Furthermore, common RNA targets of MATR3 and hnRNPM converge in biological processes important for neuronal health and survival. Conclusions We propose a model of MATR3-mediated neuromuscular degeneration governed by its RNA-binding domains and modulated by interaction with splicing factor hnRNPM.

scholarly journals The Circadian RNA-Binding Protein CHLAMY 1 Represents a Novel Type Heteromer of RNA Recognition Motif and Lysine Homology Domain-Containing Subunits

2004 ◽  
Vol 3 (3) ◽  
pp. 815-825 ◽  
Author(s):  
Bin Zhao ◽  
Claudia Schneid ◽  
Dobromir Iliev ◽  
Eva-Maria Schmidt ◽  
Volker Wagner ◽  
...  
Keyword(s):  
Protein Complex ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Binding Activity ◽  
Rna Recognition Motif ◽  
Rna Recognition ◽  
Biochemical Purification ◽  
Interaction Domain ◽  
Recognition Motif

ABSTRACT The RNA-binding protein CHLAMY 1 from Chlamydomonas reinhardtii binds specifically to UG(≥7) repeat sequences situated in the 3′ untranslated regions of several mRNAs. Its binding activity is controlled by the circadian clock. The biochemical purification and characterization of CHLAMY 1 revealed a novel type of RNA-binding protein. It includes two different subunits (named C1 and C3), whose interaction appears necessary for RNA binding. One of them (C3) belongs to the proteins of the CELF (CUG-BP-ETR-3-like factors) family and thus bears three RNA recognition motif domains. The other is composed of three lysine homology domains and a protein-protein interaction domain (WW). The subunits C1 and C3 have theoretical molecular masses of 45 and 52 kDa, respectively, and are present in nearly equal amounts during the circadian cycle. At the beginning of the subjective night, both can be found in protein complexes of 100 to 160 kDa. However, during subjective day when binding activity of CHLAMY 1 is low, the C1 subunit in addition is present in a high-molecular-mass protein complex of more than 680 kDa. These data indicate posttranslational control of the circadian binding activity of CHLAMY 1. Notably, the C3 subunit shows significant homology to the rat CUG-binding protein 2. Anti-C3 antibodies can recognize the rat homologue, which can also be found in a protein complex in this vertebrate.

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