https://scholar.dgist.ac.kr/handle/20.500.11750/722 2026-04-04T13:58:03Z https://scholar.dgist.ac.kr/handle/20.500.11750/60138 Title: 광유전학적으로 활성화 가능한 팔미토일화 조절 단백질 및 이의 용도 Author(s): 서병창; 연준희; 김별이 Abstract: 본 발명의 광유전학적으로 활성화 가능한 팔미토일화 조절 융합 단백질은 광조사를 통해 세포막의 지질뗏목 부위와 비지질뗏목 부위에 존재하는 목표 단백질의 팔미토일화-탈팔미토일화 순환을 가역적으로 조절할 수 있어, 세포 및 개체에 무해하며 팔미토일화와 관련된 질환에 대한 우수한 진단, 예방 및 치료 효과를 나타낼 수 있다. https://scholar.dgist.ac.kr/handle/20.500.11750/60082 Title: Involvement of multiple taste receptors in the actions of Kokumi taste stimuli Author(s): Rhyu, Mee-Ra; Kim, Yiseul; Suh, Byung-Chang; Jeong, Da-Jeong; Bigiani, Albertino; Lyall, Vijay Abstract: Kokumi taste stimuli are ligands that activate the calcium-sensing receptor (CaSR). Kokumi stimuli elicit flavor persistence and richness, and also modulate basic tastes, such as enhance salt taste. Most γ-glutamyl peptides produce Kokumi taste as natural allosteric modulators of CaSR. We investigated the effects of γ-Glu-Cys-Gly (GSH) and γ-Glu-Val-Gly (γ-EVG) on salt taste using patch clamp technique and calcium signaling. Salt detection is mediated by at least two pathways. A Na+ selective pathway that utilizes the amiloride (Am)-sensitive epithelial Na+ channel (ENaC), and a cation non-selective pathway that is Am-insensitive. Patch-clamp studies using rat fungiform taste cells expressing ENaC provided direct evidence that GSH and γ-EVG do not alter ENaC activity. We further investigated if Kokumi taste substances can modulate salt response via the Am-insensitive pathway(s). We monitored temporal changes in [Ca2+] in HEK293T cells expressing the human vanilloid receptor 1 (hTRPV1), a non-selective cation channel, which has been suggested as a potential Am-insensitive salt taste mediator. GSH and γ-EVG induced concentration-dependent changes in [Ca2+] that were markedly attenuated in the presence of capsazepine, a specific TRPV1 antagonist. In cells expressing capsaicin-insensitive hTRPV1 mutants, the apparent affinity of hTRPV1 for GSH and γ-EVG was significantly reduced. These results suggest that multiple taste receptors may be potentially involved in the actions of Kokumi taste stimuli. 2025-09-15T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59928 Title: Palmitoylation Code and Endosomal Sorting Regulate ABHD17A Plasma Membrane Targeting and Activity Author(s): Kim, Byeol I; Yeon, Jun-Hee; Suh, Byung-Chang Abstract: Protein S-palmitoylation is a reversible lipid modification that regulates various aspects of protein function, including membrane association, subcellular localization, trafficking, stability, and activity. The depalmitoylase ABHD17A removes palmitate from multiple substrates, but its cellular positioning and the role of its own palmitoylation in regulating its function remain unclear. This study identifies a palmitoylation code within the conserved N-terminal cysteine cluster of ABHD17A, which governs its intracellular distribution and plasma membrane (PM) targeting. N-terminal palmitoylation is essential for PM localization. Through the use of code-restricted mutants, we found that modifications in the middle region (C14, C15) are critical for PM targeting and catalytic activity, while modifications at the front (C10, C11) and rear (C18) influence endosomal routing and delivery to the PM. Alanine scanning revealed that adjacent hydrophobic residues, particularly L9 and F13, are crucial for initial engagement with endomembranes. Sequence analysis and mutagenesis identified two tyrosine-based YXX & Oslash; motifs within the alpha/beta hydrolase fold; disruption of the proximal motif (L115A) decreased surface abundance and redirected ABHD17A to autophagosomes, indicating a need for YXX & Oslash;-dependent endosomal sorting, likely at the trans-Golgi network. Biochemical assays demonstrated a continuum of acylation states influenced by the palmitoylation code. This requirement for the middle region was conserved in ABHD17B and ABHD17C. Overall, our findings suggest a stepwise mechanism for ABHD17A delivery to the PM, enabling its depalmitoylase activity on membrane-bound substrates. 2025-09-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59927 Title: Kv7 Channels as an Important Contributor to Alcohol-Induced Modulation of Neuronal Excitability in Neonatal Rat Superior Cervical Ganglion Author(s): Jeong, Da-Jeong; Woo, Jin-Nyeong; Yun, Tery; Baek, Myungin; Suh, Byung-Chang Abstract: Normal alcohols (n-alcohols) exhibit contrasting effects on neuronal excitability; specifi- cally, ethanol enhances neuronal firing, while hexanol suppresses it. Both compounds are known to inhibit sodium currents, yet the mechanisms behind their differing effects remain unclear. Our previous studies demonstrated that Kv7 channels are modulated differently by alcohol chain length, prompting investigation into their role in these contrasting effects. We conducted whole-cell patch clamp recordings on neonatal (P5-P7) rat superior cervical ganglion neurons to assess alcohol impacts on action potential firing and ionic currents, utilizing tetrodotoxin (TTX), XE991, and retigabine (RTG). Ethanol (100 mM) increased action potential frequency, whereas hexanol (3 mM) decreased it, despite both inhibiting sodium currents by 12% and 45%, respectively. Notably, ethanol inhibited Kv7 currents by 16%, while hexanol enhanced them by 29%. TTX alone did not affect firing frequency until sodium current inhibition exceeded 76%, indicating moderate sodium channel blockade cannot fully explain the effects of alcohol. XE991 increased firing frequency and depo- larized the resting membrane potential, while retigabine produced opposite effects. The combination of TTX with Kv7 modulators replicated the effects observed with each alco- hol. These findings suggest Kv7 channel modulation plays an important role in the chain length-dependent effects of alcohol on neuronal excitability. 2025-10-31T15:00:00Z