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Biology subjects

Chang, L.-Y.

Publications and source records attributed to Chang, L.-Y..

3 recordsLinked to original sources

Targeting Wnt Signaling and DNAJB6/MRJ-L as a Dual Anti-RSV Strategy: Insights into a Positive Regulatory Loop

Respiratory syncytial virus (RSV) is a major cause of severe respiratory infections, yet effective treatments are lacking. We found that the molecular chaperon DNAJB6/MRJ plays an essential role in RSV replication. Depletion of the long isoform of MRJ (MRJ-L) suppresses RSV replication. Transcriptomic analysis revealed that MRJ-L depletion downregulates Wnt signaling pathways. A pharmacological inhibitor of Wnt signaling suppressed RSV propagation and unexpectedly reduced MRJ-L expression, suggesting a positive regulatory loop between Wnt signaling and MRJ-L expression. Notably, simultaneous inhibition of Wnt signaling and MRJ-L additively suppressed RSV replication, suggesting that the Wnt-MRJ-L axis may serve as a new therapeutic target. This study provides insights into host-RSV interactions and potential antiviral strategies. Author SummaryThe molecular chaperone DNAJB6/MRJ has been implicated in the replication of respiratory syncytial virus (RSV), although the precise mechanisms remain unclear. In this study, we discovered that MRJ may influence RSV replication via Wnt signaling pathways. Specifically, we demonstrated that Wnt signaling inhibitor Wnt-C59 significantly reduced RSV replication by suppressing the synthesis of viral mRNA and genome/antigenome. Moreover, a positive feedback loop of the Wnt-MRJ axis may play a critical role in regulating RSV replication. Importantly, RSV replication was suppressed additively by inhibition of Wnt signaling and depletion of MRJ-L. Thus, a dual-targeted therapeutic approach may be effective in combating RSV infections.

pathology↗

Bioinformatic and experimental evidence for suicidal and catalytic plant THI4s

Like fungi and some prokaryotes, plants use a thiazole synthase (THI4) to make the thiazole precursor of thiamin. Fungal THI4s are suicide enzymes that destroy an essential active-site Cys residue to obtain the sulfur atom needed for thiazole formation. In contrast, certain prokaryotic THI4s have no active-site Cys, use sulfide as sulfur donor, and are truly catalytic. The presence of a conserved active-site Cys in plant THI4s and other indirect evidence implies that they are suicidal. To confirm this, we complemented the Arabidopsis tz-1 mutant, which lacks THI4 activity, with a His-tagged Arabidopsis THI4 construct. LC-MS analysis of tryptic peptides of the THI4 extracted from leaves showed that the active-site Cys was predominantly in desulfurated form, consistent with THI4 having a suicide mech-anism in planta. Unexpectedly, transcriptome datamining and deep proteome profiling showed that barley, wheat, and oat have both a widely expressed canonical THI4 with an active-site Cys, and a THI4-like paralog (non-Cys THI4) that has no active-site Cys and is the major type of THI4 in devel-oping grains. Transcriptomic evidence also indicated that barley, wheat, and oat grains synthesize thiamin de novo, implying that their non-Cys THI4s synthesize thiazole. Structure modeling supported this inference, as did demonstration that non-Cys THI4s have significant capacity to complement thia-zole auxotrophy in Escherichia coli. There is thus a prima facie case that non-Cys cereal THI4s, like their prokaryotic counterparts, are catalytic thiazole synthases. Bioenergetic calculations show that, relative to suicide THI4s, such enzymes could save substantial energy during the grain filling period. AbbreviationsDHAla, dehydroalanine; EST, expressed sequence tag; FDR, false discovery rate; IPTG, {beta}-D-1-thiogalactopyranoside

plant biology↗

Stout camphor tree genome fills gaps in understanding of flowering plant genome and gene family evolution

We present reference-quality genome assembly and annotation for the stout camphor tree (SCT; Cinnamomum kanehirae [Laurales, Lauraceae]), the first sequenced member of the Magnoliidae comprising four orders (Laurales, Magnoliales, Canellales, and Piperales) and over 9,000 species. Phylogenomic analysis of 13 representative seed plant genomes indicates that magnoliid and eudicot lineages share more recent common ancestry relative to monocots. Two whole genome duplication events were inferred within the magnoliid lineage, one before divergence of Laurales and Magnoliales and the other within the Lauraceae. Small scale segmental duplications and tandem duplications also contributed to innovation in the evolutionary history of Cinnamomum. For example, expansion of terpenoid synthase subfamilies within the Laurales spawned the diversity of Cinnamomum monoterpenes and sesquiterpenes.

genomics↗