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Ye, A.

Publications and source records attributed to Ye, A..

3 recordsLinked to original sources

Type one protein phosphatases (TOPPs) catalyze EIN2 dephosphorylation to regulate ethylene signaling in Arabidopsis

TOPPs (Type one protein phosphatases) widely modulate plant hormone signaling and stress responses in plants, but their roles in ethylene signal transduction remain unknown. This study reveals a reciprocal regulatory relationship between TOPPs and EIN2 (Ethylene insensitive 2)-mediated ethylene signaling. We identified that ethylene can induce TOPPs expression, and topp1/4/5 triple mutants exhibited partial ethylene insensitivity with reduced EIN3 protein levels and ERF1 (Ethylene response factor 1) expression. Mechanistically, TOPPs genetically act upstream of EIN2, physically interacting with its carboxyl-terminal domain (EIN2-C) to dephosphorylate the critical S655 residue. This site-specific dephosphorylation promotes EIN2 stability and EIN2-C nuclear accumulation, thereby activating ethylene responses. Notably, transgenic plants expressing phosphorylation-deficient EIN2S655A displayed constitutive ethylene responses and improved salt tolerance. Further investigation showed that EIN3/EIL1 (EIN3 like 1) transcriptionally activates TOPPs expression by binding to their promoter, amplifying ethylene signaling accordingly. Together, our finding establishes TOPPs play an important regulatory role in ethylene signal transduction and elucidate a dephosphorylation-switch mechanism in controlling EIN2 function, providing critical insight into the role of EIN2 post-translational modifications in plant stress adaptation.

plant biology↗

cxcl18b-defined transitional state-specific nitric oxide drives injury-induced Müller glia cell-cycle re-entry in the zebrafish retina

In lower vertebrates, retinal Muller glia (MG) exhibit a life-long capacity of cell-cycle re-entry to regenerate neurons following the retinal injury. However, the mechanism driving such injury-induced MG cell-cycle re-entry remains incompletely understood. Combining single-cell transcriptomic analysis and in-vivo clonal analysis, we identified previously undescribed cxcl18b-defined MG transitional states as essential routes towards MG proliferation following green/red cone (G/R cone) ablation. Inflammation blockage abolished the triggering of these transitional states, which expressed the gene modules shared by cells of the ciliary marginal zone (CMZ), where life-long adult neurogenesis takes place. Functional studies of the redox properties of these transitional states further demonstrated the regulatory role of nitric oxide (NO) produced by Nos2b in injury-induced MG proliferation. Finally, we developed a viral-based strategy to specifically disrupt nos2b in cxcl18b-defined MG transitional states and revealed the effect of transitional state-specific NO signaling. Our findings elucidate the precision redox mechanism underlying injury-induced MG cell-cycle re-entry, providing insights into species-specific mechanisms for vertebrate retina regeneration.

neuroscience↗

The lipid Gb3 promotes germinal center B cell responses and anti-viral immunity

Influenza viruses escape immunity due to rapid antigenic evolution, which requires vaccination strategies that allow for broadly protective antibody responses. Here, we demonstrate that the lipid globotriaosylceramide (Gb3) expressed on germinal center (GC) B cells is essential for the production of high-affinity antibodies. Mechanistically, Gb3 binds and disengages CD19 from its chaperone CD81 for subsequent translocation to the B cell receptor (BCR) complex to trigger signaling. Abundance of Gb3 amplifies the PI3-kinase/Akt/Foxo1 pathway to drive affinity maturation. Moreover, this lipid regulates MHC-II expression to increase diversity of T follicular helper (Tfh) and GC B cells reactive with subdominant epitopes. In influenza infection, Gb3 promotes broadly reactive antibody responses and cross-protection. Thus, we show that Gb3 determines affinity as well as breadth in B cell immunity and propose this lipid as novel vaccine adjuvant against viral infection. One Sentence SummaryGb3 abundance on GC B cells selects antibodies with high affinity and broad epitope reactivities, which are cross-protective against heterologous influenza infection.

immunology↗