scholarly journals Expression of potato RNA-binding proteins StUBA2a/b and StUBA2c induces hypersensitive-like cell death and early leaf senescence in Arabidopsis

2015 ◽  
Vol 66 (13) ◽  
pp. 4023-4033 ◽  
Author(s):  
Jong-Kuk Na ◽  
Jae-Kwang Kim ◽  
Dool-Yi Kim ◽  
Sarah M. Assmann
Keyword(s):  
Cell Death ◽  
Leaf Senescence ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Early Leaf Senescence

scholarly journals The Developmentally Active and Stress-Inducible Noncoding hsrω Gene Is a Novel Regulator of Apoptosis in Drosophila

Genetics ◽  
2009 ◽  
Vol 183 (3) ◽  
pp. 831-852 ◽  
Author(s):  
Moushami Mallik ◽  
Subhash C. Lakhotia
Keyword(s):  
Cell Death ◽  
Noncoding Rna ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Genetic Interaction ◽  
Apoptotic Cell ◽  
Cell Death Pathway ◽  
Apoptosis Protein ◽  
Multiple Paths

The large nucleus limited noncoding hsrω-n RNA of Drosophila melanogaster is known to associate with a variety of heterogeneous nuclear RNA-binding proteins (hnRNPs) and certain other RNA-binding proteins to assemble the nucleoplasmic omega speckles. In this article, we show that RNAi-mediated depletion of this noncoding RNA dominantly suppresses apoptosis, in eye and other imaginal discs, triggered by induced expression of Rpr, Grim, or caspases (initiator as well as effector), all of which are key regulators/effectors of the canonical caspase-mediated cell death pathway. We also show, for the first time, a genetic interaction between the noncoding hsrω transcripts and the c-Jun N-terminal kinase (JNK) signaling pathway since downregulation of hsrω transcripts suppressed JNK activation. In addition, hsrω-RNAi also augmented the levels of Drosophila Inhibitor of Apoptosis Protein 1 (DIAP1) when apoptosis was activated. Suppression of induced cell death following depletion of hsrω transcripts was abrogated when the DIAP1-RNAi transgene was coexpressed. Our results suggest that the hsrω transcripts regulate cellular levels of DIAP1 via the hnRNP Hrb57A, which physically interacts with DIAP1, and any alteration in levels of the hsrω transcripts in eye disc cells enhances association between these two proteins. Our studies thus reveal a novel regulatory role of the hsrω noncoding RNA on the apoptotic cell death cascade through multiple paths. These observations add to the diversity of regulatory functions that the large noncoding RNAs carry out in the cells' life.

scholarly journals Shaping the size of a neuronal lineage: the role of Imp and Syp RBPs in the precise elimination of neurons by apoptosis.

2021 ◽  
Author(s):  
Jonathan ENRIQUEZ ◽  
Wenyue GUAN ◽  
Mathilde BOUCHET ◽  
Aurelien DARMAS
Keyword(s):  
Stem Cells ◽  
Cell Death ◽  
Stem Cell ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Neuronal Survival ◽  
Neuronal Stem Cells ◽  
Immature Neurons ◽  
Two Parameters

Neuronal stem cells produce a finite and stereotyped number of neuronal progenies. This process must be finely regulated during development and adult stages to ensure proper brain function. In Drosophila, stem cells, called Neuroblasts, produce an invariant number of neurons. Two RNA binding proteins, Imp and Syp, play a central role in controlling the speed of division and the end of the proliferative phase of individual NBs, two parameters that influences the final number of neurons produced. Here, we have discovered a novel function for Imp and Syp, where both RBPs shape the number of neurons produced by a stem cell by controlling program cell death (PCD) in immature neurons. By studying a neuroblast lineage, called Lin A/15, which produces motoneurons (MNs) and glia, we have demonstrated that Lin A/15 stem cell spends 40% of its time producing immature MNs which are eliminated by apoptosis. We have revealed that only the first born MNs (Imp +) survive while the last born MNs (Imp- Syp+) are eliminated by apoptosis. Both RBPs play a central role in neuronal survival, Imp promotes neuronal survival while Syp promotes cell death in immature motoneurons. Interestingly their opposite temporal gradient in Lin A/15 stem cell also determines the end of Lin A/15 stem cell neurogenesis by PCD. Both RNA binding proteins are conserved in vertebrates and seem to play a central role in the number of neurons produce during development. The Drosophila model and its genetic tools offer a unique chance to decipher their function in neural stem cell versus immature neurons.

scholarly journals Characterization of caspase-7 interaction with RNA

2021 ◽  
Author(s):  
Alexandre Desroches ◽  
Jean-Bernard Denault
Keyword(s):  
Cell Death ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Amino Acid Sequences ◽  
Binding Assays ◽  
Rna Molecules ◽  
Caspase 7

Apoptosis is a regulated form of cell death essential to the removal of unwanted cells. At its core, a family of cysteine peptidases named caspases cleaves key proteins allowing cell death to occur. To do so, each caspase catalytic pocket recognizes preferred amino acid sequences resulting in proteolysis, but some also use exosites to select and cleave important proteins efficaciously. Such exosites have been found in a few caspases, notably caspase-7 that has a lysine patch (K38KKK) that binds RNA which acts as a bridge to RNA-binding proteins favoring proximity between the peptidase and its substrates resulting in swifter cleavage. Although caspase-7 interaction with RNA has been identified, in-depth characterization of this interaction is lacking. In this study, using in vitro cleavage assays, we determine that RNA concentration and length affect the cleavage of RNA-binding proteins. Additionally, using binding assays and RNA sequencing, we found that caspase-7 binds RNA molecules regardless of their type, sequence, or structure. Moreover, we demonstrate that the N-terminal peptide of caspase-7 reduces the affinity of the peptidase for RNA which translates into slower cleavages of RNA-binding proteins. Finally, employing engineered heterodimers, we show that a caspase-7 dimer can use both exosites simultaneously to increase its affinity to RNA because a heterodimer with only one exosite has reduced affinity for RNA and cleavage efficacy. These findings shed light on a mechanism that furthers substrate recognition by caspases and provides potential insight into its regulation during apoptosis.

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