Biotechnology for Biofuels and Bioproducts
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2024
·Vol. 17
·期 1
·1-17
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IF 3.3
Liu Lin,Wang Zhixing,Fang Yu,Yang Renfei,Pu Yi,Meng Xiangfeng,Liu Weifeng
Background The saprophytic filamentous fungus Trichoderma reesei represents one of the most prolific cellulase producers. The bulk production of lignocellulolytic enzymes by T. reesei not only relies on the efficient transcription of cellulase genes but also their efficient secretion after being translated. However, little attention has been paid to the functional roles of the involved secretory pathway in the high-level production of cellulases in T. reesei. Rab GTPases are key regulators in coordinating various vesicle trafficking associated with the eukaryotic secretory pathway. Specifically, Rab7 is a representative GTPase regulating the transition of the early endosome to the late endosome followed by its fusion to the vacuole as well as homotypic vacuole fusion. Although crosstalk between the endosomal/vacuolar pathway and the secretion pathway has been reported, the functional role of Rab7 in cellulase production in T. reesei remains unknown.Results A TrRab7 was identified and characterized in T. reesei. TrRab7 was shown to play important roles in T. reesei vegetative growth and vacuole morphology. Whereas knock-down of Trrab7 significantly compromised the induced production of T. reesei cellulases, overexpression of the key transcriptional activator, Xyr1, restored the production of cellulases in the Trrab7 knock-down strain (Ptcu-rab7KD) on glucose, indicating that the observed defective cellulase biosynthesis results from the compromised cellulase gene transcription. Down-regulation of Trrab7 was also found to make T. reesei more sensitive to various stresses including carbon starvation. Interestingly, overexpression of Snf1, a serine/threonine protein kinase known as an energetic sensor, partially restored the cellulase production of Ptcu-rab7KD on Avicel, implicating that TrRab7 is involved in an energetic adaptation to carbon starvation which contributes to the successful cellulase gene expression when T. reesei is transferred from glucose to cellulose.Conclusion sTrRab7 was shown to play important roles in T. reesei development and a stress response to carbon starvation resulting from nutrient shift. This adaptation may allow T. reesei to successfully initiate the inducing process leading to efficient cellulase production. The present study provides useful insights into the functional involvement of the endosomal/vacuolar pathway in T. reesei development and hydrolytic enzyme production.
研究领域:
微生物学
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分子生物学
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酶工程
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DOI
高影响因子
Advanced Science
·
2024
·
IF 14.3
Jiahan Ke,Jianan Pan,Hao Lin,Shuying Huang,Junfeng Zhang,Changqian Wang,Alex Chia Yu Chang,Jun Gu
Diabetic cardiomyopathy (DbCM) is characterized by diastolic dysfunction, which progresses into heart failure and aberrant electrophysiology in diabetic patients. Dyslipidemia in type 2 diabetic patients leads to the accumulation of lipid droplets (LDs) in cardiomyocytes and results in lipid toxicity which has been suggested to drive DbCM. It is aimed to explore potential pathways that may boost LDs degradation in DbCM and restore cardiac function. LDs accumulation resulted in an increase in lipid toxicity in DbCM hearts is confirmed. Microlipophagy pathway, rather than traditional macrolipophagy, is activated in DbCM hearts. RNA-Seq data and Rab7-CKO mice implicate that Rab7 is a major modulator of the microlipophagy pathway. Mechanistically, Rab7 is phosphorylated at Tyrosine 183, which allows the recruitment of Rab-interacting lysosome protein (Rilp) to proceed LDs degradation by lysosome. Treating DbCM mice with Rab7 activator ML-098 enhanced Rilp level and rescued the observed cardiac dysfunction. Overall, Rab7-Rilp-mediated microlipophagy may be a promising target in the treatment of lipid toxicity in DbCM is suggested.
研究领域:
心脏病学
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细胞生物学
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分子生物学
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药理学
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DOI
PubMed
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-16
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IF 15.7
Peng Wang,Chen Shu,Ma Jingyu,Wei Wenjie,Lin Naixin,Xing Jinchao,Guo Wenjing,Li Heying,Zhang Liang,Chan Kuiming,Yen Andrew,Zhu Guangyu,Yue Jianbo
The interplay between lipid droplets (LDs) and endosomes remains unknown. Here, we screen and synthesize AP1-coumarin, an LD-specific probe, by conjugating a fluorescent dye coumarin to a triazine compound AP1. AP1-coumarin labels all stages of LDs in live cells and markedly induces the accumulation of enlarged RAB5-RAB7 double-positive intermediate endosomes. The AP1-coumarin-labeled LDs contact these intermediate endosomes, with some LDs even being engulfed in them. When LD biogenesis is inhibited, the ability of AP1-coumarin to label LDs is markedly reduced, and the accumulation of enlarged intermediate endosomes is abolished. Moreover, blocking the biogenesis of LDs decreases the number of late endosomes while increasing the number of early endosomes and inhibits the endosomal trafficking of low-density lipoprotein (LDL) and transferrin. Correspondingly, interference with RAB5 or RAB7, either through knockdown or using dominant-negative mutants, inhibits LD catabolism, whereas the expression of a RAB7 constitutively active mutant accelerates LD catabolism. Additionally, CCZ1 knockdown not only induces the accumulation of intermediate endosomes but also inhibits LD catabolism. These results collectively suggest that LDs and endosomes interact and influence each other’s functions, and endosomal trafficking participates in the catabolic process of LDs to maintain lipid homeostasis.
研究领域:
细胞生物学
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脂质代谢
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分子生物学
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产品关联
DOI
PubMed
高影响因子
PLANT PHYSIOLOGY
·
2022
·Vol. 189
·期 3
·1416-1434
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IF 8.005
Jiang Dong,He Yilin,Zhou Xiangui,Cao Zhiran,Pang Lei,Zhong Sheng,Jiang Liwen,Li Ruixi
The homotypic fusion and protein sorting (HOPS) complex is a conserved, multi-subunit tethering complex in eukaryotic cells. In yeast and mammalian cells, the HOPS subunit vacuolar protein sorting-associated protein 41 (VPS41) is recruited to late endosomes after Ras-related protein 7 (Rab7) activation and is essential for vacuole fusion. However, whether VPS41 plays conserved roles in plants is not clear. Here, we demonstrate that in the model plant Arabidopsis (Arabidopsis thaliana), VPS41 localizes to distinct condensates in root cells in addition to its reported localization at the tonoplast. The formation of condensates does not rely on the known upstream regulators but depends on VPS41 self-interaction and is essential for vegetative growth regulation. Genetic evidence indicates that VPS41 is required for both homotypic vacuole fusion and cargo sorting from the adaptor protein complex 3, Rab5, and Golgi-independent pathways but is dispensable for the Rab7 cargo inositol transporter 1. We also show that VPS41 has HOPS-independent functions in vacuolar transport. Taken together, our findings indicate that Arabidopsis VPS41 is a unique subunit of the HOPS complex that carries out plant-specific roles in both vacuolar transport and developmental regulation.
研究领域:
植物生物学
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细胞生物学
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分子遗传学
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DOI
PubMed
高影响因子
Alzheimers Research & Therapy
·
2025
·Vol. 17
·期 1
·1-22
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IF 7.6
Wang Yangyang,Li Siyu,Liang Xiao,Fan Jianing,Li Shijie,Zhou Fanlin,Li Xiaoju,Lai Mengmeng,Feng Dianmao,Li Yu
Background: Dysregulation retrograde axonal transport in neurons results in autophagosome accumulation, enhancing amyloid β (Aβ) production and accelerating Alzheimer’s disease (AD) progression. Ras-associated GTP-binding protein 7 (Rab7) is pivotal in autophagosome maturation and their fusion with lysosomes, as well as in bidirectional axonal transport through interactions with partner proteins. Recent studies suggest that adapter-associated protein complex 2 subunit α1 (AP2A1) modulates retrograde axonal autophagosomes transport, regulates autophagy, and influences AD progression. However, the interplay between AP2A1 and Rab7, along with the molecular mechanisms underlying their impact on neuronal autophagy in AD, remains poorly understood.
Methods: We employed N2a/APPswe cells, primary hippocampal neurons exposed to Aβ oligomers, and APP/PS1 transgenic mice as AD models. To assess the impact of AP2A1 on Rab7 activity and autophagy, we conducted Rab7 pulldown activation assay, transmission electron microscopy (TEM), western blot and immunofluorescence (IF) staining were performed. The interaction between AP2A1 and Rab7 was examined by co-immunoprecipitation (Co-IP), IF staining and molecular docking. Live-cell imaging was utilized to monitor autophagosome axonal transport in primary hippocampal neurons. Aβ levels were quantified through immunohistochemistry and ELISA. Behavioral alterations in mice were evaluated using the Morris water maze, open field test, object recognition test and Y-maze.
Results: We observed reduced levels of AP2A1 and Rab7-GTP, accompanied by autophagosome accumulation, in AD models. Overexpression of AP2A1 restored autophagic flux in these cells. AP2A1 was found to bind and activate Rab7, facilitating the recruitment of retrograde axonal transport proteins DIC1 and RILP. Additionally, AP2A1 overexpression enhanced retrograde axonal autophagosome transport, reinstated autophagic flux, provided neuroprotection, and improved behavioral deficits in AD model mice through Rab7 activation.
Conclusions: Our findings demonstrate that AP2A1 activates Rab7 to restore autophagic function and mitigate AD progression, providing novel therapeutic perspectives for autophagy-targeted interventions in AD.
Supplementary Information: The online version contains supplementary material available at 10.1186/s13195-025-01771-1.
Keywords: AP2A1; Alzheimer’s disease; Autophagosome; Autophagy; Axonal retrograde transport; Rab7.
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PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2026
·
IF 11.3
Jinchen Jiang,Haixia Meng,Zhenhao Shu,Nannan Zhao,Xiaojun Lin,Jianglan Li,Minjun Qin,Siyu Wu,Lianglin Qiu
As an emerging alternative to perfluorooctanesulfonate (PFOS), 6:2 chlorinated polyfluoroalkyl ether sulfonate (6:2 Cl-PFAES) is associated with male reproductive disorders, yet its testicular targets and mechanisms remain unclear. This study combined in vivo exposure of male C57BL/6J mice (0, 4, 40, and 400 μg/L for 18 weeks) and in vitro assays in primary Leydig cells to demonstrate that 6:2 Cl-PFAES dose-dependently reduced sperm count and serum/testicular testosterone, accompanied by testicular interstitial vacuolation. Transcriptomics and metabolomics demonstrated the concurrent significant enrichment of autophagy pathways and disruption of lipid metabolism. Mechanistically, 6:2 Cl-PFAES suppressed expressions of Sirtuin 1 (SIRT1), ras-related GTP binding protein 7 (RAB7), and deacetylation of forkhead box class O1 (FOXO1), thereby impairing lipophagy flux and promoting lipid droplets accumulation. Molecular docking indicated comparable binding affinity of 6:2 Cl-PFAES and PFOS to SIRT1 (−10.4 kcal/mol), and further research demonstrated that 6:2 Cl-PFAES reduced the deacetylation activity of SIRT1. Crucially, Sirt1 overexpression in transgenic mice (Sirt1TG) or pharmacological activation of SIRT1 (SRT1720) and RAB7 (ML-098) rescued testosterone synthesis and restored lipophagy flux. This study identifies the SIRT1–FOXO1–RAB7 axis as a core target for 6:2 Cl-PFAES-induced suppression of testosterone biosynthesis via lipophagy dysregulation, providing critical molecular insights for assessing the reproductive risks of PFOS alternatives.
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高影响因子
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