Biology subjects

Chen, I.-H.

Publications and source records attributed to Chen, I.-H..

3 recordsLinked to original sources

bioRxiv2026

The cap-independent translational regulation of NbRabGAP1 in Nicotiana benthamiana during BaMV infection

While cap-dependent translation is the eukaryotic norm, alternative pathways enable selective protein synthesis during stress. We describe a cap-independent mechanism regulating NbRabGAP1, a host factor essential for bamboo mosaic virus (BaMV) movement in Nicotiana benthamiana. The 5' untranslated region (5' UTR, 553-nt) of NbRabGAP1 contains three upstream open reading frames (uORFs) that typically hinder ribosome scanning. Using bicistronic reporter assays, we identified a functional internal ribosome entry site (IRES) within nucleotides 61-150. This IRES features a predicted stable Y-shaped RNA structure and a purine-rich R-motif. We demonstrate that NbPAB8, a poly(A)-binding protein, specifically binds this R-motif to enhance IRES-mediated translation over 2.5-fold. During BaMV infection, NbPAB8 expression is transiently upregulated, coinciding with maintained NbRabGAP1 levels despite potential repression of global cap-dependent translation. This represents a regulatory switch where viral infection triggers a PAB8-dependent IRES mechanism to sustain the vesicle trafficking machinery required for viral movement. Our findings reveal how viral stress rewires host translational control through specific RNA-protein interactions, ensuring the synthesis of critical host factors via IRES-mediated pathways. HighlightDuring bamboo mosaic virus infection, NbPAB8 binds a purine-rich IRES in the NbRabGAP1 5' UTR, bypassing global translation repression to maintain vesicle trafficking essential for viral movement.

molecular biology↗

bioRxiv2025

FishProx: Proximate conspecific interaction of Atlantic salmon (Salmo salar) for behavioural analysis through instance segmentation masks

In modern fish production and experimental facilities, camera installations are increasingly common for monitoring animal welfare. This opens up a new alley of autonomous tracking systems levering streamed data. However, the substantial amount of data necessitates condensation for human operators. In this paper, we present the out-of-the-box pipeline called FishProx that starts with the imagery of fish in tanks and ends in the calculation of welfare impacting factors through anomaly scores. The utilisation of the Segment Anything Model (SAM) is the basis for the identification of feeding behaviour and also (ab)normal behaviour through analysing snapshots of the fish tanks to infer metrics such as fish cohesion and cluster alignment, alongside the detection count. Our method employs automatic and robust algorithms for camera systems, making additional labelled data unnecessary, thereby saving energy and costs. Furthermore, automatic fish observation coupled with integrated analytical capabilities can lead to a sensible autonomous decision-making process. Lastly, by providing objective metrics, our approach might guide the enabling of automatic quantification of fish states, making comparative studies possible.

animal behavior and cognition↗

bioRxiv2018

An E3 ubiquitin ligase from Nicotiana benthamiana targets the replicase of Bamboo mosaic virus and restricts its replication

One upregulated host gene identified previously was found involved in the infection process of Bamboo mosaic virus (BaMV). The full-length cDNA of this gene was cloned by 5'- and 3'-rapid amplification of cDNA ends and found to encode a polypeptide containing a conserved RING-domain and a transmembrane domain. The gene might function as an E3 ubiquitin ligase. We designated this protein in Nicotiana benthamiana as ubiquitin E3 ligase containing RING-domain 1 (NbUbE3R1). Further characterization by using Tobacco rattle virus-based virus-induced gene silencing revealed an increased BaMV accumulation in both knockdown plants and protoplasts. To further inspect the functional role of NbUbE3R1 in BaMV accumulation, NbUbE3R1 was expressed in N. benthamiana plants. The wild-type NbUbE3R1-orange fluorescent protein (NbUbE3R1-OFP), NbUbE3R1/{bigtriangleup}TM-OFP (removal of the transmembrane domain) and NbUbE3R1/mRING-OFP (mutation at the RING domain, the E2 interaction site) were transiently expressed in plants. NbUbE3R1 and its derivatives all functioned in restricting BaMV accumulation. The common feature of these constructs was the intact substrate-interacting domain. Yeast two-hybrid and co-immunoprecipitation experiments used to determine the possible viral-encoded substrate of NbUbE3R1 revealed the replicase of BaMV as the possible substrate. In conclusion, we identified an upregulated gene, NbUbE3R1, that plays a role in BaMV replication.

microbiology↗