Mammalian cells concentrate Golgi membranes around the centrosome in a microtubule-dependent manner. The mechanisms involved in generating a single Golgi ribbon in the periphery of the centrosome remain unknown. Here we show that GMAP-210, a cis-Golgi microtubule binding protein, recruits gamma-tubulin-containing complexes to Golgi membranes even in conditions where microtubule polymerization is prevented and independently of Golgi apparatus localization within the cell. Under overexpression conditions, very short microtubules, or tubulin oligomers, are stabilized on Golgi membranes. GMAP-210 depletion by RNA interference results in extensive fragmentation of the Golgi apparatus, supporting a role for GMAP-210 in Golgi ribbon formation. Targeting of GMAP-210 or its C terminus to mitochondria induces the recruitment of gamma-tubulin to their surface and redistribution of mitochondria to a pericentrosomal location. All our experiments suggest that GMAP-210 displays microtubule anchoring and membrane fusion activities, thus contributing to the assembly and maintenance of the Golgi ribbon around the centrosome.
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http://dx.doi.org/10.1016/j.cell.2004.07.012 | DOI Listing |
Plant Physiol
January 2025
State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China, P. R.
Mitochondria have generated the bulk of ATP to fuel cellular activities, including membrane trafficking, since the beginning of eukaryogenesis. How inhibition of mitochondrial energy production will affect the form and function of the endomembrane system and whether such changes are specific in today's cells remain unclear. Here, we treated Arabidopsis thaliana with antimycin A (AA), a potent inhibitor of the mitochondrial electron transport chain (mETC), as well as other mETC inhibitors and an uncoupler.
View Article and Find Full Text PDFJ Cell Sci
January 2025
Program in Molecular Medicine, University of Massachusetts Chan Medical School, Suite 213 Biotech II, 373 Plantation Street, Worcester MA 01605, USA.
In humans, inositol polyphosphate-5-phosphatase e (INPP5E) mutations cause retinal degeneration as part of Joubert and MORM syndromes and can also cause non-syndromic blindness. In mice, mutations cause a spectrum of brain, kidney, and other anomalies and prevent the formation of photoreceptor outer segments. To further explore the function of Inpp5e in photoreceptors, we generated conditional and inducible knockouts of mouse Inpp5e where the gene was deleted either during outer segment formation or after outer segments were fully formed.
View Article and Find Full Text PDFPLoS One
January 2025
Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Muenster, Muenster, Germany.
Weibel-Palade bodies (WPB) are secretory organelles exclusively found in endothelial cells and among other cargo proteins, contain the hemostatic von-Willebrand factor (VWF). Stimulation of endothelial cells results in exocytosis of WPB and release of their cargo into the vascular lumen, where VWF unfurls into long strings of up to 1000 µm and recruits platelets to sites of vascular injury, thereby mediating a crucial step in the hemostatic response. The function of VWF is strongly correlated to its structure; in order to fulfill its task in the vascular lumen, VWF has to undergo a complex packing/processing after translation into the ER.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, 690041 Vladivostok, Russia.
The ultrastructural organization of the nuclei of the tegmental region in juvenile chum salmon () was examined using transmission electron microscopy (TEM). The dorsal tegmental nuclei (DTN), the nucleus of (NFLM), and the nucleus of the oculomotor nerve (NIII) were studied. The ultrastructural examination provided detailed ultrastructural characteristics of neurons forming the tegmental nuclei and showed neuro-glial relationships in them.
View Article and Find Full Text PDFJ Neuroinflammation
January 2025
Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.
The brain presents various structural and functional sex differences, for which multiple factors are attributed: genetic, epigenetic, metabolic, and hormonal. While biological sex is determined by both sex chromosomes and sex hormones, little is known about how these two factors interact to establish this dimorphism. Sex differences in the brain also affect its resident immune cells, microglia, which actively survey the brain parenchyma and interact with sex hormones throughout life.
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