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Golgi Morphology (golgi + morphology)

Distribution by Scientific Domains
Life Sciences100%

Selected Abstracts

EMBRYO YELLOW gene, encoding a subunit of the conserved oligomeric Golgi complex, is required for appropriate cell expansion and meristem organization in Arabidopsis thaliana

GENES TO CELLS, Issue 6 2008
Takaaki Ishikawa
We identified an embryo yellow (eye) mutation in Arabidopsis that leads to the abnormal coloration and morphology of embryos. The eye mutant formed bushy plants, with aberrant organization of the shoot apical meristem (SAM) and unexpanded leaves with irregular phyllotaxy. The epidermal cells of the eye mutant were much smaller than that of the wild-type. Thus, EYE is required for expansion of cells and organs, and for formation of the organized SAM. Hydrophobic layers of epidermal cells were also disrupted, suggesting that EYE might be involved in the generation of the extra-cellular matrix. The mutated gene encoded a protein that is homologous to Cog7, a subunit of the conserved oligomeric Golgi (COG) complex, which is required for the normal morphology and function of the Golgi appratus. The eye mutation caused mislocalization of a Golgi protein. In addition, the size of the Golgi apparatus was also altered. Thus, EYE might be involved in transport or retention of Golgi-localized proteins and in maintenance of Golgi morphology. We propose that some Golgi-localized proteins, distributions of which are controlled by EYE, play important roles in expansion of cells and organs, and in formation of the properly organized SAM in plants. [source]

The Salmonella SpiC protein targets the mammalian Hook3 protein function to alter cellular trafficking

MOLECULAR MICROBIOLOGY, Issue 6 2003
Yoram Shotland
Summary The Salmonella SpiC protein is secreted into the cytosol of macrophages via a unique type III secretion system that functions intracellularly to translocate proteins across the phagosomal membrane. The SpiC protein is required for survival within macrophages and inhibition of phagosome-lysosome fusion in vivo, and it is sufficient to inhibit endosome-endosome fusion in vitro. Here, we establish that SpiC targets the function of Hook3, a mammalian protein implicated in cellular trafficking. Purified GST-SpiC pulled down Hook3 from murine macrophages, and anti-Hook3 antibodies precipitated SpiC from the cytosol of Salmonella -infected macrophages. Expression of the spiC gene disrupted Golgi morphology in Vero cells and altered the distribution of lysosomes in macrophages, mimicking the phenotype of cells expressing a hook3 dominant-negative mutant. By inactivating Hook3 function, the SpiC protein may alter the lysosome network and prevent phagosome-lysosome fusion. [source]

Quantitative analysis of neuronal diversity in the mouse olfactory bulb

THE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 6 2007
S. Parrish-Aungst
Abstract Olfactory sensory information is processed and integrated by circuits within the olfactory bulb. Golgi morphology suggests the olfactory bulb contains several major neuronal classes. However, an increasingly diverse collection of neurochemical markers have been localized in subpopulations of olfactory bulb neurons. While the mouse is becoming the animal model of choice for olfactory research, little is known about the proportions of neurons expressing and coexpressing different neurochemical markers in this species. Here we characterize neuronal populations in the mouse main olfactory bulb, focusing on glomerular populations. Immunofluorescent labeling for: 1) calretinin, 2) calbindin D-28K (CB), 3) parvalbumin, 4) neurocalcin, 5) tyrosine hydroxylase (TH), 6) the 67-kDa isoform of GAD (GAD67), and 7) the neuronal marker NeuN was performed in mice expressing green fluorescent protein under the control of the glutamic acid decarboxylase 65kDa (GAD65) promoter. Using unbiased stereological cell counts we estimated the total numbers of cells and neurons in the bulb and the number and percentage of neurons expressing and coexpressing different neurochemical populations in each layer of the olfactory bulb. Use of a genetic label for GAD65 and immunohistochemistry for GAD67 identified a much larger percentage of GABAergic neurons in the glomerular layer (55% of all neurons) than previously recognized. Additionally, while many glomerular neurons expressing TH or CB coexpress GAD, the majority of these neurons preferentially express the GAD67 isoform. These data suggest that the chemospecific populations of neurons in glomeruli form distinct subpopulations and that GAD isoforms are preferentially regulated in different neurochemical cell types. J. Comp. Neurol. 501:825,836, 2007. © 2007 Wiley-Liss, Inc. [source]

Essential role of the V-ATPase in male gametophyte development

THE PLANT JOURNAL, Issue 1 2005
Jan Dettmer
Summary Intracellular pH homeostasis is a prerequisite for biological processes and requires the action of proton pumps. The vacuolar H+ -ATPase (V-ATPase) is involved in regulating pH in endomembrane compartments of all eukaryotic cells. In plants, there is an additional endomembrane proton pump, H+ -pyrophosphatase (H+ -PPase). However, the relative roles of the two types of pumps in endomembrane acidification and energization of secondary active transport are unclear. Here, we show that a strong T-DNA insertion allele of VHA-A, the single copy gene encoding the catalytic subunit of the Arabidopsis V-ATPase, causes complete male and partial female gametophytic lethality. Severe changes in the morphology of Golgi stacks and Golgi-derived vesicles in male gametophytes are the first visible symptoms of cell degeneration leading to a failure to develop mature pollen. Similar effects on Golgi morphology were observed in pollen tubes when growth was blocked by Concanamycin A, a specific V-ATPase inhibitor. Taken together, our results suggests that V-ATPase function is essential for Golgi organization and development of the male gametophyte. [source]