Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/451211

Silencing cathepsin L expression reduces Myzus persicae protein content and the nutritional value as prey for Coccinella septempunctata

Rauf, I.·Asif, M.·Amin, I.·Naqvi, R. Z.·Umer, N.·Mansoor, S.·Jander, G.
View original source ↗Export metadata ↓

Abstract

Gut-expressed aphid genes, which may be more easily inhibited by RNA interference (RNAi) constructs, are attractive targets for pest control efforts involving transgenic plants. Here we show that expression of cathepsin L, a cysteine protease that functions in aphid guts, can be reduced by expression of an RNAi construct in transgenic tobacco. The effectiveness of this approach is demonstrated by up to 80% adult mortality, reduced fecundity, and delayed nymph production of Myzus persicae (green peach aphids) when cathepsin L expression was reduced by plant-mediated RNAi. Consistent with the function of cathepsin L as a gut protease, M. persicae fed on the RNAi plants had a lower protein content in their bodies and excreted more protein in their honeydew. Larvae of Coccinella septempunctata (seven-spotted ladybugs) grew more slowly on aphids having reduced cathepsin L expression, suggesting that prey insect nutritive value, and not just direct negative effects of the RNAi construct, needs to be considered when producing transgenic plants for RNAi-mediated pest control.\n\nHighlightsO_LISilencing expression of cathepsin L by RNA interference reduces protein content of Myzus persicae (green peach aphid) bodies.\nC_LIO_LIHoneydew of aphids with cathepsin L silenced contains elevated protein.\nC_LIO_LICathepsin L is required for efficient protein uptake from phloem sap.\nC_LIO_LIAphids with cathepsin L expression silenced have increased mortality and fewer offspring.\nC_LIO_LICoccinella septempunctata (seven-spotted ladybugs) grow more slowly on aphids with expression of cathepsin L silenced.\nC_LI\n\n\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=173 SRC=\"FIGDIR/small/451211_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (26K):\norg.highwire.dtl.DTLVardef@5ee6d7org.highwire.dtl.DTLVardef@853fe8org.highwire.dtl.DTLVardef@26c2aborg.highwire.dtl.DTLVardef@b67e2b_HPS_FORMAT_FIGEXP M_FIG C_FIG

Source connections

Explore related subjects

molecular biologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Rauf, I., Asif, M., Amin, I., Naqvi, R. Z., Umer, N., Mansoor, S., Jander, G.. 2018-10-24. Silencing cathepsin L expression reduces Myzus persicae protein content and the nutritional value as prey for Coccinella septempunctata. https://doi.org/10.1101/451211

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

IER3-N-cadherin axis contributes to apoptosis resistance in dermal fibroblasts under profibrotic conditions

Background: Persistent activation and resistance to apoptosis of dermal fibroblasts contribute to pathological skin fibrosis. Immediate early response 3 (IER3) is a stress-responsive protein involved in cell survival, but its role in cutaneous fibrosis remains unclear. We investigated the functional significance of IER3 in dermal fibroblasts and its potential contribution to fibrosis. Methods: IER3 expression was examined in skin samples from patients with systemic sclerosis, keloids, and hypertrophic scars. Primary human dermal fibroblasts were stimulated with transforming growth factor-{beta}1 (TGF-{beta}1). RNA sequencing, siRNA-mediated gene silencing, quantitative PCR, and flow cytometric apoptosis assays were performed to investigate the downstream mechanisms and functional consequences of IER3 expression. Results: IER3 expression was increased in dermal fibroblasts within fibrotic skin lesions and was induced by TGF-{beta}1 independently of SMAD3 and MEK/ERK signaling. Transcriptomic analysis identified CDH2, encoding N-cadherin, as a downstream target of IER3. Moreover, TGF-{beta}1 induced CDH2 expression in a SMAD3 phosphorylation-dependent manner. IER3 knockdown attenuated TGF-{beta}1-induced CDH2 expression, whereas CDH2 knockdown did not affect IER3 expression. Furthermore, CDH2 knockdown enhanced staurosporine-induced apoptosis in TGF-{beta}1-stimulated fibroblasts, accompanied by a shift in apoptosis-related gene expression toward a pro-apoptotic profile. Conclusion: Our findings identify a previously unrecognized IER3-N-cadherin regulatory axis that may promote dermal fibroblast survival by suppressing apoptosis under profibrotic conditions. Targeting this pathway may represent a novel therapeutic strategy for persistent skin fibrosis.

molecular biology↗
bioRxiv2026

Molecular basis of Cyclin B1-CDK1 recruitment by MAD1

The interaction between Cyclin B1-CDK1 and MAD1 recruits kinase activity to the nuclear pore complex and kinetochore corona to sustain spindle assembly checkpoint (SAC) signaling. Here, we characterize a short linear motif (SLiM) within MAD1 that mediates its interaction with Cyclin B1. This SLiM peptide is specific for B-type cyclins and lacks the canonical "RxL" cyclin-binding consensus sequence, suggesting a distinct mode of cyclin recognition. Using a combination of deep mutational scanning, structural analysis by cryogenic electron microscopy, and binding affinity measurements, we define the molecular basis of the Cyclin B1-MAD1 interaction. These approaches reveal that a short MAD1 peptide binds as an -helix to the RxL-binding hydrophobic patch of Cyclin B1. The interaction employs hydrophobic contacts that overlap with those used by canonical RxL motifs, but is distinguished by additional contacts and sequence features that confer preferential recognition by B-type cyclins while excluding other cyclin types. We also show that the MAD1 motif is sufficient to confer B-type cyclin-specific substrate phosphorylation in mitotic cells. Together, these findings reveal a non-canonical, B-type cyclin-specific helical binding mode that ensures selective Cyclin B1-CDK1 recruitment at two critical stages of SAC signaling, and suggest potential strategies for selective therapeutic targeting of this interaction.

molecular biology↗
bioRxiv2026

Characterizing nascent readthrough transcripts in human cells

Termination of transcription by RNA polymerase II (RNAPII) is critical to appropriately define transcriptome and proteome identity; yet mechanisms of termination regulation are incompletely understood. Current models suggest critical roles for the exonuclease XRN2, which is posited to "torpedo" out RNAPII after degrading uncapped and RNAPII-tethered nascent transcripts and posit an allosteric model wherein elongating RNAPII loses its processivity downstream of the transcription end site (TES) via unknown mechanisms. Here, we used nascent RNA Bru-seq to interrogate transcription termination across 16 human cell lines of distinct lineages, as part of the ENCODE 4 project, to identify key regulatory modes. We find that > 75% of protein-coding genes engage in readthrough transcription under homeostatic conditions. Exposing human cells to oxidative stress or hyperosmotic conditions or splicing inhibitors cause an increase in readthrough transcripts globally. Using an auxin-inducible degradation approach we find that depletion of BRD4, MED14 or XRN2 increases the extent and pervasiveness of readthrough transcripts while depletion of SUPT16H results in shorter readthrough transcripts. Our study provides a comprehensive view of homeostatic readthrough transcripts in human cells and delineates key components regulating transcription termination.

molecular biology↗