Proteasome Inhibitors Affect Appressorium Formation and Pathogenicity of the Rice Blast Fungus, Magnaporthe oryzae

Wang, Yiming,Kim, Sang-Gon,Wu, Jingni,Yu, Seok,Kang, Kyu-Young,Kim, Sun-Tae The Korean Society of Plant Pathology 2011 Plant Pathology Journal Vol.27 No.3

Previously, we identified the 20S proteasome ${\alpha}$-subunit of Magnaporthe oryzae (M. oryzae) induced during appressorium formation, and detected an increase in multiple protein ubiquitination during the early appressorium formation process (Kim et al., 2004). In this study, we further attempted to determine whether the proteasome is involved in the appressorium formation of M. oryzae both in vitro and in planta, using proteasome inhibitors. A significant increase in 20S proteasome during fungal germination and appressorium formation was observed using Western blot analysis with 20S proteasome antibody, demonstrating that proteasome-mediated protein degradation was involved in appressorium formation. Pharmacological analysis using proteasome inhibitors, MG-132, proteasome inhibitor I (PI) and proteasome inhibitor II (PII) revealed that germination and appressorium formation were delayed for 4 to 6 h on rice leaf wax-coated plates. Similarly, the treatment of proteasome inhibitors with fungal conidia on the rice leaf surface delayed appressorium formation and host infection processes as well. Additionally, fungal pathogenicity was strongly reduced at 4 days' postfungal infection. These data indicated that the fungal 20S proteasome might be involved in the pathogenicity of M. oryzae by the suppression of germination and appressorium formation.

Proteasome Inhibitors Affect Appressorium Formation and Pathogenicity of the Rice Blast Fungus, Magnaporthe oryzae

Yiming Wang,김상곤,Jingni Wu,Seok Yu,강규영,김선태 한국식물병리학회 2011 Plant Pathology Journal Vol.27 No.3

Previously, we identified the 20S proteasome α-subunit of Magnaporthe oryzae (M. oryzae) induced during appressorium formation, and detected an increase in multiple protein ubiquitination during the early appressorium formation process (Kim et al., 2004). In this study, we further attempted to determine whether the proteasome is involved in the appressorium formation of M. oryzae both in vitro and in planta, using proteasome inhibitors. A significant increase in 20S proteasome during fungal germination and appressorium formation was observed using Western blot analysis with 20S proteasome antibody, demonstrating that proteasomemediated protein degradation was involved in appressorium formation. Pharmacological analysis using proteasome inhibitors, MG-132, proteasome inhibitor I (PI) and proteasome inhibitor II (PII) revealed that germination and appressorium formation were delayed for 4 to 6 h on rice leaf wax-coated plates. Similarly, the treatment of proteasome inhibitors with fungal conidia on the rice leaf surface delayed appressorium formation and host infection processes as well. Additionally, fungal pathogenicity was strongly reduced at 4 days’ postfungal infection. These data indicated that the fungal 20S proteasome might be involved in the pathogenicity of M. oryzae by the suppression of germination and appressorium formation.

K_ATP channel block prevents proteasome inhibitor-induced apoptosis in differentiated PC12 cells

Nam, Yoon Jeong,Lee, Da Hee,Lee, Min Sung,Lee, Chung Soo Elsevier 2015 european journal of pharmacology Vol.764 No.-

<P><B>Abstract</B></P> <P>Dysfunction of the proteasome system has been suggested to be implicated in neuronal degeneration. Modulation of K<SUB>ATP</SUB> channels appears to affect the viability of neuronal cells exposed to toxic insults. However, the effect of K<SUB>ATP</SUB> channel blockers on the neuronal cell death mediated by proteasome inhibition has not been studied. The present study investigated the effect of K<SUB>ATP</SUB> channel blockers on proteasome inhibitor-induced apoptosis in differentiated PC12 cells and SH-SY5Y cells. 5-Hydroxydecanoate (a selective K<SUB>ATP</SUB> channel blocker) and glibenclamide (a cell surface and mitochondrial K<SUB>ATP</SUB> channel inhibitor) reduced the proteasome inhibitor-induced apoptosis. Addition of the K<SUB>ATP</SUB> channel blockers attenuated the proteasome inhibitor-induced changes in the levels of apoptosis-related proteins, the loss of the mitochondrial transmembrane potential, the increase in the formation of reactive oxygen species and the depletion of glutathione in both cell lines. The results show that K<SUB>ATP</SUB> channel blockers may attenuate proteasome inhibitor-induced apoptosis in PC12 cells by suppressing activation of the mitochondrial pathway and of the caspase-8- and Bid-dependent pathways. The preventive effect appears to be associated with the inhibition of the formation of reactive oxygen species and the depletion of glutathione. K<SUB>ATP</SUB> channel blockade appears to prevent proteasome inhibition-induced neuronal cell death.</P>

부위-특이적 억제제에 의한 26S와 20S Proteasome의 억제

우기민 순천향대학교 순천향의학연구소 2018 Journal of Soonchunhyang Medical Science Vol.24 No.1

Objective: The study was performed to establish the purification processes of both 26S and 20S proteasomes, also to investigate the inhibitory properties and patterns of two different proteasome inhibitors on the isolated proteasomes. Methods: The 26S and 20S proteasomes were purified respectively using liquid chromatographies and glycerol density gradient fractionation. The inhibitory patterns and kinetics of two different proteasome inhibitors were investigated using purified 26S and 20S proteasomes. Results: The purity of the isolated proteasomes were determined by their biochemical properties and electrophoretic patterns. 3-nitro-4-hydroxy-5-indophenylacetyl-leucyl-leucyl-leucyl-vinylsulfone (Nip-L3-VS) inhibited exclusively the chymotrypsin-like peptidase activities of the 26S and 20S proteasomes. On the other hand, dansyl-phenylyl-leucyl-boronic acid (DFLB) inhibited chymotrpsin- like, trypsin-like, and caspase-like peptidase activities of both proteasomes with different sensitivity. Conclusion: The proposed purification method provides efficient separation and isolation of the 26S and 20S proteasomes. Nip-L3- VS and DFLB were shown to have different inhibitory effects and kinetics on the peptidase activities of the isolated proteasomes. These studies are suggested to be applied to the researches on proteasome inhibitors as therapeutic reagents for many related diseases.

Proteasome inhibitors attenuated cholesterol-induced cardiac hypertrophy in H9c2 cells

( Hyun Jung Lee ),( Jin Young Park ),( Eunice Eunkyeong Kim ),( Young Sook Yoo ),( Eun Joo Song ) 생화학분자생물학회(구 한국생화학분자생물학회) 2016 BMB Reports Vol.49 No.6

The Ubiquitin proteasome system (UPS) plays roles in protein degradation, cell cycle control, and growth and inflammatory cell signaling. Dysfunction of UPS in cardiac diseases has been seen in many studies. Cholesterol acts as an inducer of cardiac hypertrophy. In this study, the effect of proteasome inhibitors on the cholesterol-induced hypertrophic growth in H9c2 cells is examined in order to observe whether UPS is involved in cardiac hypertrophy. The treatment of proteasome inhibitors MG132 and Bortezomib markedly reduced cellular surface area and mRNA expression of β-MHC in cholesterol-induced cardiac hypertrophy. In addition, activated AKT and ERK were significantly attenuated by MG132 and Bortezomib in cholesterol-induced cardiac hypertrophy. We demonstrated that cholesterol-induced cardiac hypertrophy was suppressed by proteasome inhibitors. Thus, regulatory mechanism of cholesterol-induced cardiac hypertrophy by proteasome inhibitors may provide a new therapeutic strategy to prevent the progression of heart failure. [BMB Reports 2016; 49(5): 270-275]

Proteasome inhibitors attenuated cholesterol-induced cardiac hypertrophy in H9c2 cells

( Hyunjung Lee ),( Jinyoung Park ),( Eunice Eunkyeong Kim ),( Young Sook Yoo ),( Eun Joo Song ) 생화학분자생물학회(구 한국생화학분자생물학회) 2016 BMB Reports Vol.49 No.5

The Ubiquitin proteasome system (UPS) plays roles in protein degradation, cell cycle control, and growth and inflammatory cell signaling. Dysfunction of UPS in cardiac diseases has been seen in many studies. Cholesterol acts as an inducer of cardiac hypertrophy. In this study, the effect of proteasome inhibitors on the cholesterol-induced hypertrophic growth in H9c2 cells is examined in order to observe whether UPS is involved in cardiac hypertrophy. The treatment of proteasome inhibitors MG132 and Bortezomib markedly reduced cellular surface area and mRNA expression of β-MHC in cholesterol-induced cardiac hypertrophy. In addition, activated AKT and ERK were significantly attenuated by MG132 and Bortezomib in cholesterol- induced cardiac hypertrophy. We demonstrated that cholesterol- induced cardiac hypertrophy was suppressed by proteasome inhibitors. Thus, regulatory mechanism of cholesterol- induced cardiac hypertrophy by proteasome inhibitors may provide a new therapeutic strategy to prevent the progression of heart failure. [BMB Reports 2016; 49(5): 270-275]

저산소환경이 일차 배양된 대뇌겉질 신경세포의 ubiquitin-proteasome system에 미치는 영향

양성준(Seong-Jun Yang),김민정(Min-Jung Kim),정호중(Ho-Joong Jeong),김기찬(Ghi-Chan Kim),길영기(Young-Gi Gil),김강련(Kang-Ryune Kim),김현(Hyun Kim) 대한체질인류학회 2008 대한체질인류학회지 Vol.21 No.1

저산소환경에 만성으로 노출된 경우 신경세포는 적응하기 위하여 세포 내의 다양한 신호 경로의 활성화를 통해 반응한다. 그 중 ubiquitin-proteasome system은 세포의 생존을 위한 핵심적인 기전으로 proteasome이 억제될 때 비정상적인 단백질이 세포 내에 축적되어 세포자멸사와 신경세포의 퇴행이 일어난다. 이번 실험에서 저자들은 ubiquitin-proteasome system을 억제하는 proteasome 억제제와 저산소환경이 일차 배양한 대뇌 겉질 세포에 미치는 영향을 관찰하였으며, 도파민생성 세포에서의 결과와 비교하였다. 저산소환경이나 합성된 억제제인 PSI (Z-lle-Glu(OtBu)-Ala-Leu-al)를 투여한 신경세포의 자멸사는 증가하였으며, PARP와 caspase 3의 활성도 증가하였다. 특히 NF-κB의 발현이 PSI를 처리한 경우와 저산소환경에서 증가하였다. 저산소환경에서 배양한 신경세포에 PSI를 처리한 경우에는 이들 단백질의 발현이 현저하게 증가하였다. α-synuclein의 발현 역시 증가하였는데 특히 저산소환경에서 현저하게 증가하였다. 이 실험을 통해 저산소환경과 proteasome 억제제를 처리했을 경우 신경세포의 자멸사가 증가하였을 뿐 아니라, α-synuclein의 생성 및 NF-κB의 발현이 증가하였음을 확인하였다. 이를 통해 저산소환경이 ubiquitin-proteasome system을 교란할 수 있음을 제시하였다. 이러한 결과는 저산소환경이 신경퇴행성질환의 원인이 될 수 있음을 제시하는 것이다. The ubiquitin-proteasome system is crucial in maintaining cellular growth and metabolism. Dysfunction of this system may contribute to neurodegenerative diseases, such as Parkinson’s disease. But its effects on primary neurons are largely unknown. In the present study, we investigated the effects of proteasome inhibitor and hypoxia on primary neuronal cultures to determine whether proteasomal malfunction induces neuronal death. Neuronal apoptosis increased in primary cultured cortical neurons with treatment of proteasomal inhibitor in normoxic condition and in the presence or absence of proteasomal inhibitor in hypoxic condition. Also expression of PARP and activated caspase 3 increased. NF-κB, a key transcription factor in this system expression increased in hypoxic condition and proteasomal inhibition. Interestingly, hypoxic condition induced an expression and accumulation of α-synuclein in neuron, one of components of Lewy body in Parkinson’s disease. Our findings determine that hypoxic condition may affect the ubiquitin-proteasome system. Furthermore, it suggests that hypoxic condition and proteasomal inhibitors are involved, at least in parts, in neurodegeneration of mouse model for Parkinson’s disease.

보골지 및 염초보골지의 proteasome 저해 작용

심상희,Shim, Sang-Hee 한국생약학회 2008 생약학회지 Vol.39 No.1

Ubiquitin-proteasome proteolytic system plays an important role in selective protein degradation and regulates cellular events including apoptosis. Cancer cells have been shown to be more sensitive to the proapoptotic effects of proteasome inhibition than normal cells. Thus, proteasome inhibitor can be potential anticancer agent. Since the MeOH extracts of psoraleae semen and processed psoraleae semen showed potent proteasome inhibition activity, the fractions of the extracts were evaluated on the activity to screen the proteasome inhibitors. The $CHCl_3$ fr. of the processed psoraleae semen showed the most potent activity, of which chemical investigation led to two coumarins, psoralen and isopsoralen. Their structures were determined by spectroscopic methods such as $^1H-NMR$ and EIMS spectra.

감잎 추출물이 HepG2 인간 간암 세포의 proteasome 활성에 미치는 영향

김소영,윤현근 한국식품과학회 2019 한국식품과학회지 Vol.51 No.4

Proteasome inhibitors can promote apoptosis and cell cycle arrest in cancer cells by inhibition of nuclear factorkappaB (NF-κB) activation. The purpose of this study was to investigate the effects of persimmon leaf extract (PSE) on proteasome activity in HepG2 human liver cancer cells. PSE treatment inhibited the proteasome activity and NF-κB activation in a dose-dependent manner in HepG2 human liver cancer cells (p<0.05). PSE treatment increased the population of cells in G2/M and sub-G1 phases. The results suggested that PSE is one of the candidate substances that may be developed into a proteasome inhibitor.

Proteasome-Dependent Degradation of RPM1 Desensitizes the RPM1-Mediated Hypersensitive Response

Mackey David,윤대진,Nam Jaesung 한국식물학회 2021 Journal of Plant Biology Vol.64 No.3

The intracellular plant resistance (R) proteins, nucleotide-binding and leucine-rich repeat (NLR) proteins, mediate resistance to pathogens by enabling recognition and rapid response. The response consists of the induction of a defensive suite that typically culminates in the hypersensitive response (HR), death of the plant cells at and around an infection site. The Arabidopsis intracellular innate immune receptor protein RESISTANCE TO PSEUDOMONAS MACULICOLA1 (RPM1) is a coiled-coil (CC) type of NLR protein that specifies resistance to strains of the bacterial pathogen Pseudomonas syringae expressing the type III effector proteins AvrRpm1 and AvrB. We previously demonstrated that RPM1-myc (an epitope-tagged version of RPM1) disappears coincident with the onset of HR induced by AvrRpm1. Infection with P. syringae expressing two other type III effector proteins, AvrRpt2 and AvrRps4, also initiated RPM1-myc disappearance at time points coincident with the HR they initiate through the NLR proteins RESISTANCE TO P. SYRINGAE2 (RPS2) and RESISTANCE TO P. SYRINGAE 4 (RPS4), respectively. Here, we use mutants impaired in NLR gene dependent signaling to demonstrate that disappearance of RPM1-myc requires normal NLR gene dependent signaling steps, but does not require HR. Inhibitors of the 26S proteasome block the disappearance of RPM1-myc and enhance RPM1-myc-dependent cell death. Our data are consistent with a model in which RPM1 is degraded by the 26S proteasome to limit the extent of RPM1-dependent signaling and/or cell death. Furthermore, AvrRpt2 induces disappearance of RPM1-myc in rps2 mutant plants without HR, suggesting that RPM1 is part of the host target of the virulence activity of AvrRpt2.