Colocalisation of acetylated microtubules, glial filaments, and mitochondria in astrocytes in vitro.
We have recently shown that acetylated alpha-tubulin containing microtubules (acetyl-MTs; labeled by antibody 6-11B-1) constitute a cold-stable subset of the microtubule network of nonneuronal cells in rat primary forebrain cultures [Cambray-Deakin and Burgoyne: Cell Motil. 8(3):284-291, 1987b]. In contrast, tyrosinated alpha-tubulin containing MTs (tyr-MTs; labeled by antibody YL1/2) are cold-labile. Here we have examined the distribution of acetyl-MTs and tyr-MTs in cultures of newborn rat forebrain astrocytes and simultaneously investigated the distribution of mitochondria and glial filaments. In double-label immunofluorescence experiments a marked colocalisation of acetyl-MTs and glial filament bundles was observed. Tyr-MTs did not show a similar colocalisation with glial filament bundles. Furthermore, the distribution of mitochondria closely followed that of the acetyl-MT and glial filament bundles. When cells were exposed to short-term (30-min) treatments with MT-disrupting agents such as colchicine and nocodazole, the tyr-MT network was removed but the distributions of acetyl-MTs, glial filaments, and mitochondria were unchanged. Increased exposure to colchicine (9-16 hr) caused a progressive disruption of the acetyl-MTs and the collapse of glial filaments and mitochondria to the perinuclear region. These results suggest that acetyl-MTs and glial filaments but not tyr-MTs may be involved in the intracellular transport of organelles and/or in the control of their cytoplasmic distribution.
D000107:Acetylation; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D001253:Astrocytes / Q000032:analysis*; D001562:Benzimidazoles / Q000494:pharmacology; D002478:Cells, Cultured; D003078:Colchicine / Q000494:pharmacology; D003599:Cytoskeleton / Q000032:analysis*; D005455:Fluorescent Antibody Technique; D007382:Intermediate Filaments / Q000032:analysis*; D008870:Microtubules / Q000032:analysis*; D008928:Mitochondria / Q000032:analysis*; D009457:Neuroglia / Q000032:analysis*; D015739:Nocodazole; D051381:Rats
D000970:Antineoplastic Agents; D001562:Benzimidazoles; D015739:Nocodazole; D003078:Colchicine