In JoVE (5)
- Detection of Protein Interactions in Plant using a Gateway Compatible Bimolecular Fluorescence Complementation (BiFC) System
- Quantitative Localization of a Golgi Protein by Imaging Its Center of Fluorescence Mass
- Preparation of Authigenic Pyrite from Methane-bearing Sediments for In Situ Sulfur Isotope Analysis Using SIMS
- In Vitro Characterization of the Electrophysiological Properties of Colonic Afferent Fibers in Rats
- Construction of an Improved Multi-Tetrode Hyperdrive for Large-Scale Neural Recording in Behaving Rats
Articles by Li Lu in JoVE
Detection of Protein Interactions in Plant using a Gateway Compatible Bimolecular Fluorescence Complementation (BiFC) System Gang Tian1, Qing Lu2, Li Zhang2, Susanne E. Kohalmi1, Yuhai Cui2 1Department of Biology, University of Western Ontario, 2Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada We have developed a technique to test protein-protein interactions in plant. A yellow fluorescent protein (YFP) is split into two non-overlapping fragments. Each fragment is cloned in-frame to a gene of interest via Gateway system, enabling expression of fusion proteins. Reconstitution of YFP signal only occurs when the inquest proteins interact.
Quantitative Localization of a Golgi Protein by Imaging Its Center of Fluorescence Mass Hieng Chiong Tie1, Bing Chen1, Xiuping Sun1, Li Cheng2,3, Lei Lu1 1School of Biological Sciences, Nanyang Technological University, 2Bioinformatics Institute, 3School of Computing, National University of Singapore The precise localization of Golgi residents is essential for understanding the cellular functions of the Golgi. However, conventional optical microscopy is unable to resolve the sub-Golgi structure. Here we describe the protocol for a conventional microscopy based super-resolution method to quantitatively determine the sub-Golgi localization of a protein.
Preparation of Authigenic Pyrite from Methane-bearing Sediments for In Situ Sulfur Isotope Analysis Using SIMS Zhiyong Lin1,3, Xiaoming Sun1,2,3,4, Jörn Peckmann5, Yang Lu2,3, Harald Strauss6, Li Xu2,3, Hongfeng Lu7, Barbara M.A. Teichert6 1School of Earth Sciences and Engineering, Sun Yat-sen University, 2School of Marine Sciences, Sun Yat-sen University, 3Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, 4South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, 5Institut für Geologie, Universität Hamburg, 6Institut für Geologie und Paläontologie, Westfälische Wilhelms-Universität Münster, 7Guangzhou Marine Geological Survey Analyses of the sulfur isotopic composition (δ34S) of pyrite from methane-bearing sediments have typically focused on bulk samples. Here, we applied secondary ion mass spectroscopy to analyze the δ34S values of various pyrite generations to understand the diagenetic history of pyritization.
In Vitro Characterization of the Electrophysiological Properties of Colonic Afferent Fibers in Rats Youqiang Meng1, Li Dong1, Biying Sun1, Ping Luo1, Guohua Zhang1, Weifang Rong1 1Hongqiao International Institute of Medical Research, Tongren Hospital and Department of Physiology, Faculty of Basic Medical Sciences, Shanghai Jiaotong University School of Medicine Abnormal sensory function underlies visceral pain and other symptoms of functional and inflammatory bowel diseases. A protocol for the electrophysiological recording of the colonic afferent nerves in an ex vivo rat colorectum preparation is presented here.
Construction of an Improved Multi-Tetrode Hyperdrive for Large-Scale Neural Recording in Behaving Rats Li Lu1, Briana Popeney1, J. David Dickman1, Dora E. Angelaki1 1Department of Neuroscience, Baylor College of Medicine We present the construction of a 3D-printable hyperdrive with eighteen independently adjustable tetrodes. The hyperdrive is designed to record brain activity in freely behaving rats over a period of several weeks.
Other articles by Li Lu on PubMed
Large Tumor Suppressor Homologs 1 and 2 Regulate Mouse Liver Progenitor Cell Proliferation and Maturation Through Antagonism of the Coactivators YAP and TAZ Hepatology (Baltimore, Md.). | Pubmed ID: 27531557 In the adult liver, the Hippo pathway mammalian STE20-like protein kinases 1 and 2 and large tumor suppressor homologs 1 and 2 (LATS1/2) control activation of the transcriptional coactivators Yes-associated protein (YAP) and WW domain containing transcription regulator 1 (TAZ) in hepatocytes and biliary epithelial cells, thereby regulating liver cell proliferation, differentiation, and malignant transformation. Less is known about the contribution of Hippo signaling to liver development. We used conditional mutagenesis to show that the Hippo signaling pathway kinases LATS1 and LATS2 are redundantly required during mouse liver development to repress YAP and TAZ in both the biliary epithelial and hepatocyte lineages. In the absence of LATS1/2, biliary epithelial cells exhibit excess proliferation while hepatoblasts fail to mature into hepatocytes, defects that result in perinatal lethality. Using an in vitro hepatocyte differentiation assay, we demonstrate that YAP activity decreases and Hippo pathway kinase activities increase upon differentiation. In addition, we show that YAP activation in vitro, resulting from either depletion of its negative regulators LATS1/2 or expression of a mutant form of YAP that is less efficiently phosphorylated by LATS1/2, results in transcriptional suppression of genes that normally accompany hepatocyte maturation. Moreover, we provide evidence that YAP activity is repressed by Hippo pathway activation upon hepatocytic maturation in vitro. Finally, we examine the localization of YAP during fetal liver development and show that higher levels of YAP are found in biliary epithelial cells, while in hepatocytes YAP levels decrease with hepatocyte maturation.
Hippo Pathway Coactivators Yap and Taz Are Required to Coordinate Mammalian Liver Regeneration Experimental & Molecular Medicine. | Pubmed ID: 29303509 The mammalian liver has a remarkable capacity for repair following injury. Removal of up to two-third of liver mass results in a series of events that include extracellular matrix remodeling, coordinated hepatic cell cycle re-entry, restoration of liver mass and tissue remodeling to return the damaged liver to its normal state. Although there has been considerable advancement of our knowledge concerning the regenerative capacity of the mammalian liver, many outstanding questions remaining, such as: how does the regenerating liver stop proliferating when appropriate mass is restored and how do these mechanisms relate to normal regulation of organ size during development? Hippo pathway has been proposed to be central in mediating both events: organ size control during development and following regeneration. In this report, we examined the role of Yap and Taz, key components of the Hippo pathway in liver organ size regulation, both in the context of development and homeostasis. Our studies reveal that contrary to the current paradigms that Yap/Taz are not required for developmental regulation of liver size but are required for proper liver regeneration. In livers depleted of Yap and Taz, liver mass is elevated in neonates and adults. However, Yap/Taz-depleted livers exhibit profound defects in liver regeneration, including an inability to restore liver mass and to properly coordinate cell cycle entry. Taken together, our results highlight requirements for the Hippo pathway during liver regeneration and indicate that there are additional pathways that cooperate with Hippo signaling to control liver size during development and in the adult.