Biology subjects

Matsui, R.

Publications and source records attributed to Matsui, R..

4 recordsLinked to original sources

bioRxiv2026

The membrane-tethered cis-ligand Belly roll elicits GPCR signaling thereby enabling adaptive avoidance behaviors

Animals adapt their behavioral responses to sensory stimuli through neuromodulatory circuits. Increasing fluid osmolality drives water-seeking behaviors via neuromodulation. However, the neural circuits and molecular mechanisms linking internal osmotic state to behavioral adaptation remain unclear. Here, we show that desiccation stress increases hemolymph osmolality and enhances avoidance of dry substrates in Drosophila larvae, enabling larvae to seek humid environments. We identify the abdominal leucokinin-producing (ABLK) neurons as a key circuit node that mediates this adaptive response. We further show that the GPI-anchored protein Belly roll (Bero), a member of the lymphocyte antigen-6/urokinase-type plasminogen activator receptor (LU) superfamily, acts as a non-canonical endogenous cis-ligand for the neuropeptide G protein-coupled receptor Allatostatin C receptor 2 (AstC-R2). Genetic, biochemical, and imaging analyses revealed that Bero activates AstC-R2 to induce phospholipase C {beta} (PLC{beta})-dependent signaling, thereby suppressing sensory transmission in ABLK neurons. Desiccation-induced increase in hemolymph osmolality activates VMA-AstC neurons to trigger Allatostatin C (AstC) release, which antagonizes Bero-mediated AstC-R2 signaling and promotes dry substrate avoidance. Together, our findings uncover a neural circuit and a molecular mechanism by which changes in internal physiological state dynamically switch GPCR signaling through the opposing actions of membrane-tethered and secreted ligands, thereby reshaping adaptive behavioral responses.

neuroscience↗

bioRxiv2024

Regional heterogeneities of oligodendrocytes determine biased distribution pattern of Ranvier nodes along single axons in sound localization circuit

Spacing of Ranvier nodes along myelinated axons is a critical determinant of conduction velocity, influencing spike arrival timing and hence neural circuit function. In the chick brainstem auditory circuit, the pattern of nodal spacing varies regionally along single axons, enabling precise binaural integration for sound localization. Using this model, we investigated the potential factors underlying the biased nodal spacing pattern. 3D morphometry revealed that these axons were almost fully myelinated by oligodendrocytes exhibiting distinct morphologies and cell densities across regions after hearing onset. The structure of axons did not affect internodal length. Inhibiting vesicular release from the axons did not affect internodal length or oligodendrocyte morphology, but caused unmyelinated segments on the axons by suppressing oligodendrogenesis near the presynaptic terminals. These results suggest that the regional heterogeneity in the intrinsic properties of oligodendrocytes is a prominent determinant of the biased nodal spacing pattern in the sound localization circuit, while activity-dependent signaling supports the pattern by ensuring adequate oligodendrocyte density. Our findings highlight the importance of oligodendrocyte heterogeneity in fine-tuning neural circuit function.

neuroscience↗

bioRxiv2023

Reentrant condensation of a multicomponent complex system of biomolecules induced by polyphosphate

Reentrant condensation (RC) is a phase behavior of protein solution comprising at least two components. In RC, a protein state varies from one phase to two phases and then back to one phase as the concentration of one component monotonically increases. To understand the phase behavior of multicomponent complex solutions of biomolecules, it is worth constructing an experimental multicomponent system that exhibits RC behavior. Here, we used a cola/milk mixture to investigate RC of a multicomponent complex system and explained the RC mechanism by reducing the system to two pure components, polyphosphate (polyP) and casein. In the multicomponent complex system, RC was observed with 20-60% cola and 1% milk. In the pure system, RC occurred with 0.01-2 mM tetraphosphate and 0.5 mg/ml casein. Moreover, the phase diagram showed that the condensation of casein depended on the chain length of the polyP. The present study succeeded in experimentally inducing RC in a multicomponent system and reproducing RC even when the system was reduced to its pure components. The fact that RC can be experimentally induced using common materials will provide important insights into the understanding of phase-separation behavior of biomolecules.

biochemistry↗

bioRxiv2017

Uncoordinated centrosome duplication cycle underlies the instability of non-diploid states in mammalian somatic cells

In animals, somatic cells are usually diploid and are unstable when haploid for unknown reasons. In this study, by comparing isogenic human cell lines with different ploidies, we found frequent centrosome loss specifically in the haploid state, which profoundly contributed to haploid instability through monopolar spindle formation and subsequent mitotic defects. We also found that efficiency of centriole licensing and duplication, but not that of DNA replication, changes proportionally to ploidy level, causing gradual loss or frequent overduplication of centrioles in haploid and tetraploid cells, respectively. Centriole licensing efficiency seemed to be modulated by astral microtubules, whose development scaled with ploidy level, and artificial enhancement of aster formation in haploid cells restored centriole licensing efficiency to diploid levels. Haploid-specific centrosome loss was also observed in parthenogenetic mouse embryos. We propose that incompatibility between the centrosome duplication and DNA replication cycles arising from different scaling properties of these bioprocesses upon ploidy changes, underlies the instability of non-diploid somatic cells in mammals.\n\nSummaryYaguchi et al. show that a delay or acceleration of centriole licensing compromises the control of centrosome number in haploid or tetraploid human cells, respectively, suggesting a cellular basis of the instability of non-diploid somatic cells in mammals.

cell biology↗