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Reduction in Golgi apparatus dimension in the absence of a residential protein, N -acetylglucosaminyltransferase V

Dong, Zhizhong ; Zuber, Christian ; Pierce, Michael ; Stanley, Pamela ; Roth, Jürgen

In: Histochemistry and Cell Biology, 2014, vol. 141, no. 2, p. 153-164

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    Title
    • Reduction in Golgi apparatus dimension in the absence of a residential protein, N -acetylglucosaminyltransferase V
    Author
    • Dong, Zhizhong. Division of Cell and Molecular Pathology, Department of Pathology, University of Zürich, 8091, Zürich, Switzerland
    • Zuber, Christian. Division of Cell and Molecular Pathology, Department of Pathology, University of Zürich, 8091, Zürich, Switzerland
    • Pierce, Michael. Complex Carbohydrate Research Center, Department of Biochemistry and Molecular Biology, University of Georgia, 30602, Athens, GA, USA
    • Stanley, Pamela. Department of Cell Biology, Albert Einstein College of Medicine, 10461, New York, NY, USA
    • Roth, Jürgen. Division of Cell and Molecular Pathology, Department of Pathology, University of Zürich, 8091, Zürich, Switzerland
    Document Type
    • Postprint
    Language
    • English
    Published in
    • Histochemistry and Cell Biology, 2014, vol. 141, no. 2, p. 153-164. Springer Berlin Heidelberg
    Other Version
    OAI-PMH Identifier
    • oai:doc.rero.ch:325659
    Summary
    Various proteins are involved in the generation and maintenance of the membrane complex known as the Golgi apparatus. We have used mutant Chinese hamster ovary (CHO) cell lines Lec4 and Lec4A lacking N-acetylglucosaminyltransferase V (GlcNAcT-V, MGAT5) activity and protein in the Golgi apparatus to study the effects of the absence of a single glycosyltransferase on the Golgi apparatus dimension. Quantification of immunofluorescence in serial confocal sections for Golgi α-mannosidase II and electron microscopic morphometry revealed a reduction in Golgi volume density up to 49% in CHO Lec4 and CHO Lec4A cells compared to parental CHO cells. This reduction in Golgi volume density could be reversed by stable transfection of Lec4 cells with a cDNA encoding Mgat5. Inhibition of the synthesis of β1,6-branched N-glycans by swainsonine had no effect on Golgi volume density. In addition, no effect on Golgi volume density was observed in CHO Lec1 cells that contain enzymatically active GlcNAcT-V, but cannot synthesize β1,6-branched glycans due to an inactive GlcNAcT-I in their Golgi apparatus. These results indicate that it may be the absence of the GlcNAcT-V protein that is the determining factor in reducing Golgi volume density. No dimensional differences existed in cross-sectioned cisternal stacks between Lec4 and control CHO cells, but significantly reduced Golgi stack hits were observed in cross-sectioned Lec4 cells. Therefore, the Golgi apparatus dimensional change in Lec4 and Lec4A cells may be due to a compaction of the organelle.