bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2024.06.11.598589

Painting cell-cell interactions by horseradish peroxidase and endogenously generated hydrogen peroxide

Jeong, I.·Kim, K.-e.·Rhee, H.-W.
View original source ↗Export metadata ↓

Abstract

Cell-Cell interactions are fundamental in biology for maintaining physiological conditions, with direct contact being the most straightforward mode of interaction. Recent advancements have led to the development of various chemical tools for detecting or identifying these interactions. However, the use of exogenous cues, such as toxic reagents, bulky probes, and light irradiations, can disrupt normal cell physiology. For example, the toxicity of hydrogen peroxide (H2O2) limits the applications of peroxidases in proximity labeling field. In this study, we aimed to address this limitation by demonstrating that membrane-localized Horseradish Peroxidase (HRP-TM) efficiently utilizes endogenously generated extracellular H2O2. By harnessing endogenous H2O2, we observed that HRP-TM-expressing cells can effectively label contacting cells without the need for exogenous H2O2 treatment. Furthermore, we confirmed that HRP-TM labels proximal cells in an interaction-dependent manner. These findings offer a novel approach for studying cell-cell interactions under more physiological conditions, without the confounding effects of exogenous stimuli. Our study contributes to elucidating cell-cell interaction networks in various model organisms, providing valuable insights into the dynamic interplay between cells in their native network.

Explore related subjects

biochemistryPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Jeong, I., Kim, K.-e., Rhee, H.-W.. 2024-06-13. Painting cell-cell interactions by horseradish peroxidase and endogenously generated hydrogen peroxide. https://doi.org/10.1101/2024.06.11.598589

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

KEEP EXPLORING

Related preprints

bioRxiv2026

EngA adopts multiple distinct conformational states during ribosome assembly

Ribosome assembly, a highly coordinated and crucial cellular process, is assisted by various assembly factors, including GTPases. EngA, an essential P-loop GTPase, is involved in late-stage assembly of the 50S ribosomal subunit. The structures of 50S ribosome in complex with EngA-bound GMPPNP, and EngA-bound GDP alone, without 50S subunit, have been reported previously. However, the molecular mechanism of EngA GTP hydrolysis-assisted 50S maturation remains poorly understood, and structures of the 50S ribosome in complex with EngA-bound GDP have yet to be deciphered. We have reported cryo- EM structures of the Mycobacterium smegmatis 50S ribosome in complex with EngA-bound GTP{gamma}S or GDP at 2.8 - 3.5 [A] resolution. Structural analysis revealed that EngA and 50S subunit undergo a coordinated structural rearrangement, and an assembly intermediate is formed in which the stem-loop of H80 makes base-pair interactions with the junction of H89 and H90, forming a unique stem-loop-junction (SLJ) motif. EngA-bound GDP adopts distinctly different conformations in its ribosome-bound and unbound states. In summary, this study proposed a multi-state conformational model for EngA-assisted ribosome assembly.

biochemistry↗
bioRxiv2026

Modular assembly of mitochondrial complex III from a dynamic matrix domain pool

Mitochondrial complex III is a central component of the cellular energy metabolism. It is an obligate dimer of catalytic and accessory subunits that are encoded by two genomes. How its large matrix domain, formed by the core proteins Qcr1 and Qcr2, is built and joined to the membrane part and during assembly is not known. Here we show that Qcr1 and Qcr2 preassemble independently of complex III into matrix domain modules. Cryo-EM structures from a cardiolipin-deficient yeast strain and of recombinant protein resolved single, double and triple matrix domains, which are linked by the C-terminal tail of Qcr1. In the mature complex III, the same tail binds cytochrome b and cardiolipin. The modules form a dynamic pool, in which assembly species interconvert and exchange subunits. Mutations at the module interfaces, including mimics of human disease variants, reshape this pool and deletion of the Qcr1 tail impairs respiratory growth. Substitution of a tyrosine residue linked to parkinsonism exposes a conserved cysteine residue to oxidation. A cryo-EM structure of an assembly intermediate shows a cap of two matrix domains bound to a monomeric membrane module of cytochrome b, Qcr7, Qcr8 and cytochrome c1. We propose that complex III receives its matrix domain from a dynamic pool of prebuilt modules, which organizes the dimerization of the complex.

biochemistry↗
bioRxiv2026

Vasopressin V2 receptor phosphopeptide reshapes the conformational landscape of arrestin-2 beyond C-tail detachment

Binding of phosphorylated GPCR tails influences arrestin conformation, but the contribution of this interaction to the interdomain rotation associated with activation remains incompletely characterised. In particular, it remains unclear whether displacement of the arrestin C-tail is sufficient to favor larger interdomain rotations or whether the bound phosphotail exerts an additional effect on the conformational landscape. Here, we used enhanced-sampling simulations to characterise the conformational free-energy landscapes of basal (unbound) and V2Rpp-bound arrestin-2. We find that V2Rpp binding broadened the range of energetically accessible interdomain rotation angles relative to basal arrestin-2. However, the pronounced rotation observed in the experimental structures, while accessible, was not strongly favored. Strikingly, C-tail displacement alone does not reproduce this effect, as arrestin-2 retains a strong preference for small interdomain rotation angles in the absence of V2Rpp. Moreover, the C-tail-detached state is energetically unfavorable in the absence of V2Rpp. Together, these findings quantify the effects of V2Rpp binding on the interdomain rotation of arrestin-2 and disentangle the effects of phosphopeptide binding from those of C-tail detachment.

biochemistry↗