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ABSTRACT: Core histones play a critical role in the regulation of chromatin-templated biological process. Here we have developed a novel approach to enrich histone proteins based on the recognition of a specific aptamer. The method shows good selectivity toward histone proteins and is able to extract histones directly from complex whole cell lysates.
Chemical Communications 05/2012; 48(53):6684-6. · 6.17 Impact Factor
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ABSTRACT: Coat complexes sort protein cargoes into vesicular transport pathways. An emerging class of coat components has been the GTPase-activating proteins (GAPs) that act on the ADP-ribosylation factor (ARF) family of small GTPases. ACAP1 (ArfGAP with coiled-coil, ankyrin repeat, and PH domains protein 1) is an ARF6 GAP that also acts as a key component of a recently defined clathrin complex for endocytic recycling. Phosphorylation by Akt has been shown to enhance cargo binding by ACAP1 in explaining how integrin recycling is an example of regulated transport. We now shed further mechanistic insights into how this regulation is achieved at the level of cargo binding by ACAP1. We initially defined a critical sequence in the cytoplasmic domain of integrin β1 recognized by ACAP1 and showed that this sequence acts as a recycling sorting signal. We then pursued a combination of structural, modeling, and functional studies, which suggest that phosphorylation of ACAP1 relieves a localized mechanism of autoinhibition in regulating cargo binding. Thus, we have elucidated a key regulatory juncture that controls integrin recycling and also advanced the understanding of how regulated cargo binding can lead to regulated transport.
Journal of Biological Chemistry 05/2012; 287(34):28675-85. · 4.77 Impact Factor
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ABSTRACT: To overcome treatment limitations of adenoid cystic carcinoma, we developed a novel treatment combining gene therapy and nanotechnology. In this study, we created a plasmid, pACTERT-TRAIL, which used the human telomerase reverse transcriptase promoter, a tumor-specific promoter, to drive tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). A Fe(3)O(4)-PEI-plasmid complex (FPP) was generated, in which the iron oxide nanoparticles were modified by positively charged polyethylenimine (PEI) to enable them to carry the negatively charged plasmid. In vitro transfection assays showed that efficiency of magnetofection (i.e., FPP transfection) was sixfold higher compared to PEI alone or Lipofectamine 2000 (hereafter referred to as lipofectin) (P < 0.05). Importantly, apoptotic assays demonstrated that FPP-mediated TRAIL gene transfer could efficiently induce apoptosis of SACC-83 cells in vitro and in vivo. These results demonstrate that magnetofection of the plasmids driven by the tumor-specific promoter hTERT provides an effective way to deliver therapeutic genes for the treatment of adenoid cystic carcinoma in the future.
Nanomedicine: nanotechnology, biology, and medicine 05/2012; · 5.44 Impact Factor
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Mingzhou Li,
Honglong Wu,
Zonggang Luo,
Yudong Xia,
Jiuqiang Guan,
Tao Wang,
Yiren Gu,
Lei Chen, Kai Zhang,
Jideng Ma, [......],
Yingrui Li,
Haosi Chen,
Xiaolian Gao,
Graham S Plastow,
Stephen Beck,
Huanming Yang,
Jian Wang,
Jun Wang,
Xuewei Li,
Ruiqiang Li
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ABSTRACT: It is evident that epigenetic factors, especially DNA methylation, have essential roles in obesity development. Here, using pig as a model, we investigate the systematic association between DNA methylation and obesity. We sample eight variant adipose and two distinct skeletal muscle tissues from three pig breeds living within comparable environments but displaying distinct fat level. We generate 1,381 Gb of sequence data from 180 methylated DNA immunoprecipitation libraries, and provide a genome-wide DNA methylation map as well as a gene expression map for adipose and muscle studies. The analysis shows global similarity and difference among breeds, sexes and anatomic locations, and identifies the differentially methylated regions. The differentially methylated regions in promoters are highly associated with obesity development via expression repression of both known obesity-related genes and novel genes. This comprehensive map provides a solid basis for exploring epigenetic mechanisms of adipose deposition and muscle growth.
Nature Communications 01/2012; 3:850. · 7.40 Impact Factor
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ABSTRACT: The cell surface receptor CED-1 mediates apoptotic cell recognition by phagocytic cells, enabling cell corpse clearance in Caenorhabditis elegans. Here, we found that the C. elegans intracellular protein sorting complex, retromer, was required for cell corpse clearance by mediating the recycling of CED-1. Retromer was recruited to the surfaces of phagosomes containing cell corpses, and its loss of function caused defective cell corpse removal. The retromer probably acted through direct interaction with CED-1 in the cell corpse recognition pathway. In the absence of retromer function, CED-1 associated with lysosomes and failed to recycle from phagosomes and cytosol to the plasma membrane. Thus, retromer is an essential mediator of apoptotic cell clearance by regulating phagocytic receptor(s) during cell corpse engulfment.
Science 03/2010; 327(5970):1261-4. · 31.20 Impact Factor
