Biology subjects

Kim, E. Y.

Publications and source records attributed to Kim, E. Y..

21 records · Page 2Linked to original sources

bioRxiv2020

SLAMF7 engagement super-activates macrophages in acute and chronic inflammation

Macrophages regulate protective immune responses to infectious microbes, but aberrant macrophage activation frequently drives pathological inflammation. To identify regulators of vigorous macrophage activation, we analyzed RNA-seq data from synovial macrophages and identified SLAMF7 as a receptor associated with a super-activated macrophage state in rheumatoid arthritis. We implicated IFN-{gamma} as a key regulator of SLAMF7 expression. Engaging this receptor drove an exuberant wave of inflammatory cytokine expression, and induction of TNF- following SLAMF7 engagement amplified inflammation through an autocrine signaling loop. We observed SLAMF7-induced gene programs not only in macrophages from rheumatoid arthritis patients, but in gut macrophages from active Crohns disease patients and lung macrophages from severe COVID-19 patients. This suggests a central role for SLAMF7 in macrophage super-activation with broad implications in pathology.

immunology↗

bioRxiv2020

Translational inhibition and phase separation primes the epigenetic silencing of transposons

Transposons are mobile DNAs that can cause fatal mutations. To counteract these genome invaders, the host genomes deploy small interfering (si) RNAs to initiate and establish the epigenetic silencing. However, the regulatory mechanisms for the selective recognition of transposons by the host genomes remain still elusive. Here we show that plant transposon RNAs undergo frequent ribosome stalling caused by their inherently unfavourable codon sequence usage. The ribosome stalling then causes the RNA truncation and the localization to siRNA bodies, which are both critical prerequisites for the siRNA processing. In addition, SGS3, the key protein in the siRNA biogenesis pathway, forms liquid droplets in vitro through its prion-like domains implicating the role of liquid-liquid phase separation in the formation of the siRNA bodies. Our study provides a novel insight into the regulatory mechanisms for the recognition of invasive genetic elements which is essential for the maintenance of genome integrity.

plant biology↗

bioRxiv2019

PLANT NATRIURETIC PEPTIDE A antagonizes salicylic acid-primed cell death

Peptide hormones perceived in the cell surface via receptor proteins enable cell-to-cell communication and act in multiple biological processes through the activation of intracellular signaling. Even though Arabidopsis is predicted to have more than 1,000 secreted peptides, the biological relevance of the majority of these is yet to be established. Here, we demonstrate that PLANT NATRIURETIC PEPTIDE A (PNP-A), a functional analog to vertebrate atrial natriuretic peptides, antagonizes the salicylic acid (SA)-mediated cell death in the Arabidopsis lesion-stimulating disease 1 (lsd1) mutant. While loss of PNP-A potentiates SA signaling, exogenous application of the PNP-A synthetic peptide or overexpression of PNP-A significantly compromises the SA-mediated cell death. Moreover, we identified a plasma membrane-localized receptor-like protein, which we name PNPAR (for PNP-A receptor), that binds PNP-A and is required to counteract SA responses. Our work identifies a novel peptide-receptor pair which modulates SA responses in Arabidopsis.

plant biology↗