scholarly journals The interactome of Cryptococcus neoformans Rmt5 reveals multiple regulatory points in fungal cell biology and pathogenesis

2022 ◽  
Author(s):  
Murat C Kalem ◽  
Harini Subbiah ◽  
Shichen Shen ◽  
Runpu Chen ◽  
Luke Terry ◽  
...  

Protein arginine methylation is a key post-translational modification in eukaryotes that modulates core cellular processes, including translation, morphology, transcription, and RNA fate. However, this has not been explored in Cryptococcus neoformans, a human-pathogenic basidiomycetous encapsulated fungus. We characterized the five protein arginine methyltransferases in C. neoformans and highlight Rmt5 as critical regulator of cryptococcal morphology and virulence. An rmt5∆ mutant was defective in thermotolerance, had a remodeled cell wall, and exhibited enhanced growth in an elevated carbon dioxide atmosphere and in chemically induced hypoxia. We revealed that Rmt5 interacts with post-transcriptional gene regulators, such as RNA-binding proteins and translation factors. Further investigation of the rmt5∆ mutant showed that Rmt5 is critical for the homeostasis of eIF2α and its phosphorylation state following 3-amino-1,2,4-triazole-induced ribosome stalling. RNA sequencing of one rmt5∆ clone revealed stable chromosome 9 aneuploidy that was ameliorated by complementation but did not impact the rmt5∆ phenotype. As a result of these diverse interactions and functions, loss of RMT5 enhanced phagocytosis by murine macrophages and attenuated disease progression in mice. Taken together, our findings link arginine methylation to critical cryptococcal cellular processes that impact pathogenesis, including post-transcriptional gene regulation by RNA- binding proteins.

2020 ◽  
Vol 21 (18) ◽  
pp. 6835
Author(s):  
Jonas Weiße ◽  
Julia Rosemann ◽  
Vanessa Krauspe ◽  
Matthias Kappler ◽  
Alexander W. Eckert ◽  
...  

Nearly 7.5% of all human protein-coding genes have been assigned to the class of RNA-binding proteins (RBPs), and over the past decade, RBPs have been increasingly recognized as important regulators of molecular and cellular homeostasis. RBPs regulate the post-transcriptional processing of their target RNAs, i.e., alternative splicing, polyadenylation, stability and turnover, localization, or translation as well as editing and chemical modification, thereby tuning gene expression programs of diverse cellular processes such as cell survival and malignant spread. Importantly, metastases are the major cause of cancer-associated deaths in general, and particularly in oral cancers, which account for 2% of the global cancer mortality. However, the roles and architecture of RBPs and RBP-controlled expression networks during the diverse steps of the metastatic cascade are only incompletely understood. In this review, we will offer a brief overview about RBPs and their general contribution to post-transcriptional regulation of gene expression. Subsequently, we will highlight selected examples of RBPs that have been shown to play a role in oral cancer cell migration, invasion, and metastasis. Last but not least, we will present targeting strategies that have been developed to interfere with the function of some of these RBPs.


2020 ◽  
Vol 21 (8) ◽  
pp. 2969 ◽  
Author(s):  
Katharina Jonas ◽  
George A. Calin ◽  
Martin Pichler

The majority of the genome is transcribed into pieces of non-(protein) coding RNA, among which long non-coding RNAs (lncRNAs) constitute a large group of particularly versatile molecules that govern basic cellular processes including transcription, splicing, RNA stability, and translation. The frequent deregulation of numerous lncRNAs in cancer is known to contribute to virtually all hallmarks of cancer. An important regulatory mechanism of lncRNAs is the post-transcriptional regulation mediated by RNA-binding proteins (RBPs). So far, however, only a small number of known cancer-associated lncRNAs have been found to be regulated by the interaction with RBPs like human antigen R (HuR), ARE/poly(U)-binding/degradation factor 1 (AUF1), insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1), and tristetraprolin (TTP). These RBPs regulate, by various means, two aspects in particular, namely the stability and the localization of lncRNAs. Importantly, these RBPs themselves are commonly deregulated in cancer and might thus play a major role in the deregulation of cancer-related lncRNAs. There are, however, still many open questions, for example regarding the context specificity of these regulatory mechanisms that, in part, is based on the synergistic or competitive interaction between different RBPs. There is also a lack of knowledge on how RBPs facilitate the transport of lncRNAs between different cellular compartments.


2021 ◽  
Author(s):  
Helisa H Wippel ◽  
Mariana Fioramonte ◽  
Juan D Chavez ◽  
James E Bruce

RNA-binding proteins (RBPs) have conserved domains and consensus sequences that interact with RNAs and other proteins forming ribonucleoprotein (RNP) complexes. RNPs are involved in the regulation of several cellular processes,...


2020 ◽  
Vol 49 (D1) ◽  
pp. D425-D436 ◽  
Author(s):  
Maiwen Caudron-Herger ◽  
Ralf E Jansen ◽  
Elsa Wassmer ◽  
Sven Diederichs

Abstract RNA–protein complexes have emerged as central players in numerous key cellular processes with significant relevance in health and disease. To further deepen our knowledge of RNA-binding proteins (RBPs), multiple proteome-wide strategies have been developed to identify RBPs in different species leading to a large number of studies contributing experimentally identified as well as predicted RBP candidate catalogs. However, the rapid evolution of the field led to an accumulation of isolated datasets, hampering the access and comparison of their valuable content. Moreover, tools to link RBPs to cellular pathways and functions were lacking. Here, to facilitate the efficient screening of the RBP resources, we provide RBP2GO (https://RBP2GO.DKFZ.de), a comprehensive database of all currently available proteome-wide datasets for RBPs across 13 species from 53 studies including 105 datasets identifying altogether 22 552 RBP candidates. These are combined with the information on RBP interaction partners and on the related biological processes, molecular functions and cellular compartments. RBP2GO offers a user-friendly web interface with an RBP scoring system and powerful advanced search tools allowing forward and reverse searches connecting functions and RBPs to stimulate new research directions.


1995 ◽  
Vol 15 (5) ◽  
pp. 2800-2808 ◽  
Author(s):  
Q Liu ◽  
G Dreyfuss

Heterogenous nuclear ribonucleoproteins (hnRNPs) bind pre-mRNAs and facilitate their processing into mRNAs. Many of the hnRNPs undergo extensive posttranslational modifications including methylation on arginine residues. hnRNPs contain about 65% of the total NG,NG-dimethylarginine found in the cell nucleus. The role of this modification is not known. Here we identify the hnRNPs that are methylated in HeLa cells and demonstrate that most of the pre-mRNA-binding proteins receive this modification. Using recombinant human hnRNP A1 as a substrate, we have partially purified and characterized a protein-arginine N-methyltransferase specific for hnRNPs from HeLa cells. This methyltransferase can methylate the same subset of hnRNPs in vitro as are methylated in vivo. Furthermore, it can also methylate other RNA-binding proteins that contain the RGG motif RNA-binding domain. This activity is evolutionarily conserved from lower eukaryotes to mammals, suggesting that methylation has a significant role in the function of RNA-binding proteins.


2019 ◽  
Vol 60 (9) ◽  
pp. 1939-1952 ◽  
Author(s):  
Wil Prall ◽  
Bishwas Sharma ◽  
Brian D Gregory

Abstract Plants have developed sophisticated mechanisms to compensate and respond to ever-changing environmental conditions. Research focus in this area has recently shifted towards understanding the post-transcriptional mechanisms that contribute to RNA transcript maturation, abundance and function as key regulatory steps in allowing plants to properly react and adapt to these never-ending shifts in their environments. At the center of these regulatory mechanisms are RNA-binding proteins (RBPs), the functional mediators of all post-transcriptional processes. In plants, RBPs are becoming increasingly appreciated as the critical modulators of core cellular processes during development and in response to environmental stimuli. With the majority of research on RBPs and their functions historically in prokaryotic and mammalian systems, it has more recently been unveiled that plants have expanded families of conserved and novel RBPs compared with their eukaryotic counterparts. To better understand the scope of RBPs in plants, we present past and current literature detailing specific roles of RBPs during stress response, development and other fundamental transition periods. In this review, we highlight examples of complex regulation coordinated by RBPs with a focus on the diverse mechanisms of plant RBPs and the unique processes they regulate. Additionally, we discuss the importance for additional research into understanding global interactions of RBPs on a systems and network-scale, with genome mining and annotation providing valuable insight for potential uses in improving crop plants in order to maintain high-level production in this era of global climate change.


2015 ◽  
Vol 183 (1) ◽  
pp. 37-49 ◽  
Author(s):  
R. Newman ◽  
J. McHugh ◽  
M. Turner

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Michael C. Yu

In eukaryotes, messenger RNA biogenesis depends on the ordered and precise assembly of a nuclear messenger ribonucleoprotein particle (mRNP) during transcription. This process requires a well-orchestrated and dynamic sequence of molecular recognition events by specific RNA-binding proteins. Arginine methylation is a posttranslational modification found in a plethora of RNA-binding proteins responsible for mRNP biogenesis. These RNA-binding proteins include both heterogeneous nuclear ribonucleoproteins (hnRNPs) and serine/arginine-rich (SR) proteins. In this paper, I discuss the mechanisms of action by which arginine methylation modulates various facets of mRNP biogenesis, and how the collective consequences of this modification impart the specificity required to generate a mature, translational- and export-competent mRNP.


2019 ◽  
Author(s):  
Huan-Huan Wei ◽  
Xiao-Juan Fan ◽  
Yue Hu ◽  
Xiao-Xu Tian ◽  
Meng Guo ◽  
...  

AbstractThousands of proteins undergo arginine methylation, a widespread post-translational modification catalyzed by various protein arginine methyltransferases (PRMTs). However, a full picture of the catalytic network for each PRMT is lacking and the global understanding of their biological roles remains limited. Here we systematically identified interacting proteins for all human PRMTs and demonstrated that they are functionally important for mRNA splicing and translation. We showed that the interactomes of human PRMTs are significantly overlapped with the known methylarginine containing proteins, and different PRMTs are functionally complementary with a high degree of overlap in their substrates and high similarities between their putative methylation motifs. Importantly, arginine methylation is significantly enriched in RNA binding proteins involved in regulating RNA splicing and translation, and inhibition of PRMTs leads to global alteration of alternative splicing and suppression of translation. In particular, ribosomal proteins are pervasively modified with methylarginine, and mutations on their methylation sites suppress ribosome assembly, translation, and eventually cell growth. Collectively, our study provides a novel global view of different PRMT networks and uncovers critical functions of arginine methylation in the regulation of mRNA splicing and translation.


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