About: DNM3 is a research topic. Over the lifetime, 14 publications have been published within this topic receiving 226 citations. The topic is also known as: Dyna III & dynamin 3.
TL;DR: Insight is given in the HIV-1-mediated CD4 down-regulation at the level of the plasma membrane and early endosomes and four possible new HIV- 1 replication co-factors are identified.
Abstract: Down-modulation of the CD4 receptor is one of the hallmarks of HIV-1 infection and it is believed to confer a selective replicative advantage to the virus in vivo. This process is mainly mediated by three viral proteins: Env, Vpu and Nef. To date, the mechanisms that lead to CD4 depletion from the surface of infected cells during HIV-1 infection are still only partially characterized. In this study, we sought to identify and characterize cellular host factors in HIV-1-induced CD4 down-modulation. To identify host factors involved in CD4 down-regulation, we used a whole genome-targeting shRNA lentiviral library in HeLa CD4+ cells expressing Nef as an inducer of CD4 down-modulation. We identified 55 genes, mainly encoding for proteins involved in various steps of clathrin-mediated endocytosis. For confirmation and further selection of the hits we performed several rounds of validation, using individual shRNA lentiviral vectors with a different target sequence for gene knock-down in HIV-1-infected T cells. By this stringent validation set-up, we could demonstrate that the knock-down of DNM3 (dynamin 3), SNX22 (sorting nexin 22), ATP6AP1 (ATPase, H+ Transporting, Lysosomal Accessory Protein 1), HRBL (HIV-Rev binding protein Like), IDH3G (Isocitrate dehydrogenase), HSP90B1 (Heat shock protein 90 kDa beta member 1) and EPS15 (Epidermal Growth Factor Receptor Pathway Substrate 15) significantly increases CD4 levels in HIV-infected SupT1 T cells compared to the non-targeting shRNA control. Moreover, EPS15, DNM3, IDH3G and ATP6AP1 knock-down significantly decreases HIV-1 replication in T cells. We identified seven genes as cellular co-factors for HIV-1-mediated CD4 down-regulation in T cells. The knock-down of four out of seven of these genes also significantly reduces HIV-1 replication in T cells. Next to a role in HIV-mediated CD4 down-regulation, these genes might however affect HIV-1 replication in another way. Our findings give insights in the HIV-1-mediated CD4 down-regulation at the level of the plasma membrane and early endosomes and identify four possible new HIV-1 replication co-factors.
TL;DR: In this article, the authors investigate the role of dynamin in dense-core vesicle endocytosis and secretory capacity in mature mouse β cells by genetically deleting dynamin GTPase.
Abstract: Pancreatic β cells operate with a high rate of membrane recycling for insulin secretion, yet endocytosis in these cells is not fully understood. We investigate this process in mature mouse β cells by genetically deleting dynamin GTPase, the membrane fission machinery essential for clathrin-mediated endocytosis. Unexpectedly, the mice lacking all three dynamin genes (DNM1, DNM2, DNM3) in their β cells are viable, and their β cells still contain numerous insulin granules. Endocytosis in these β cells is severely impaired, resulting in abnormal endocytic intermediates on the plasma membrane. Although insulin granules are abundant, their release upon glucose stimulation is blunted in both the first and second phases, leading to hyperglycemia and glucose intolerance in mice. Dynamin triple deletion impairs insulin granule exocytosis and decreases intracellular Ca2+ responses and granule docking. The docking defect is correlated with reduced expression of Munc13-1 and RIM1 and reorganization of cortical F-actin in β cells. Collectively, these findings uncover the role of dynamin in dense-core vesicle endocytosis and secretory capacity. Insulin secretion deficiency in the absence of dynamin-mediated endocytosis highlights the risk of impaired membrane trafficking in endocrine failure and diabetes pathogenesis.
TL;DR: In this paper, the role of long non-coding RNAs (lncRNAs), a class of crucial epigenetic regulatory molecules, has been under explored in skeletal biology, where a young patient with short stature, hypothalamic dysfunction and mild macrocephaly carried a maternally inherited 690kb deletion at Chr.1q24.2 encompassing a noncoding RNA gene, DNM3OS, embedded on the opposite strand in an intron of the DYNAMIN 3 (DNM3) gene.
Abstract: Skeletal development and maintenance are complex processes known to be coordinated by multiple genetic and epigenetic signaling pathways. However, the role of long non-coding RNAs (lncRNAs), a class of crucial epigenetic regulatory molecules, has been under explored in skeletal biology. Here we report a young patient with short stature, hypothalamic dysfunction and mild macrocephaly, who carries a maternally inherited 690 kb deletion at Chr.1q24.2 encompassing a noncoding RNA gene, DNM3OS, embedded on the opposite strand in an intron of the DYNAMIN 3 (DNM3) gene. We show that lncRNA DNM3OS sustains the proliferation of chondrocytes independent of two co-cistronic microRNAs miR-199a and miR-214. We further show that nerve growth factor (NGF), a known factor of chondrocyte growth, is a key target of DNM3OS-mediated control of chondrocyte proliferation. This work demonstrates that DNM3OS is essential for preventing premature differentiation of chondrocytes required for bone growth through endochondral ossification.
TL;DR: The data provide further evidence to support a functional role for non-coding RNAs in regulating the skeletal phenotype, and the potential of a functionally-impaired DNM3 protein causing the non-skeletal disease pathogenesis.
TL;DR: DNM3 may weaken the malignant behavior of colon cancer and may have promoted the invasion and migration of Colon cancer by regulating the expression of M MP-2 and MMP-9.
Abstract: Introduction Dynamin 3 (DNM3) is a large GTPase that possesses mechanochemical properties and has been shown to be involved in malignancies. However, most studies about DNM3 are observational, and knowledge of the precise molecular mechanism of DNM3 remains limited. Materials and methods We constructed a PCDH-CMV-MCS-EF1a-GFP-Puro-DNM3 recombinant eukaryotic expression vector, which was then transfected into SW620 and LoVo cells. One cell line was divided into three groups. DNM3 mRNA and protein expression was analyzed by quantitative real-time PCR and Western blot assay. To investigate DNM3 biological activity in colon cancer SW620 and LoVo cell line, we performed cell proliferation, transwell migration, and invasion assay. Matrix metalloproteinase (MMP)-2 and MMP-9 protein expressions were detected by Western blot. Result We successfully constructed a PCDH-CMV-MCS-EF1a-GFP-Puro-DNM3 recombinant eukaryotic expression vector, and stable DNM3 expression was observed in SW620 and LoVo cell lines. The vector overexpressing DNM3 inhibited the proliferation, weak invasion, and migration ability of colon cancer SW620 and LoVo cells relative to those in the control group (all P<0.001). DNM3 downregulated the protein expression of MMP-2 and MMP-9. Conclusion DNM3 may weaken the malignant behavior of colon cancer and may have promoted the invasion and migration of colon cancer by regulating the expression of MMP-2 and MMP-9.