Axonal growth is believed to depend on microtubule transport and microtubule dynamic instability. We now report that the growth of axon collateral branches can occur independent of microtubule dynamic instability and can rely mostly on the transport of preassembled polymer. Raising embryonic sensory neurons in concentrations of either taxol or nocodazole (NOC) that largely inhibit microtubule d...

The role of the cytoskeleton in regulating Ca(2+) release has been explored in epithelial cells. Trains of local Ca(2+) spikes were elicited in pancreatic acinar cells by infusion of inositol trisphosphate through a whole cell patch pipette, and the Ca(2+)-dependent Cl(-) current spikes were recorded. The spikes were only transiently inhibited by cytochalasin B, an agent that acts on microfilam...

We have re-examined the involvement of microtubules in the process of pigment granule transport in squirrelfish erythrophores in situ (i.e. on scales). Light-microscopic studies revealed that following exposure to 5 microM-nocodazole for 1 h at 4 degrees C erythrophores retained an ability to aggregate and disperse their pigment uniformly, though at reduced rates. Serial thick-section stereo hi...

Translation mechanisms at different stages of the cell cycle have been studied for many years, resulting in the dogma that translation rates are slowed during mitosis, with cap-independent translation mechanisms favored to give expression of key regulatory proteins. However, such cell culture studies involve synchronization using harsh methods, which may in themselves stress cells and affect pr...

We analysed the neurulation movements in the Mexican salamander Ambystoma mexicanum. Embryos were exposed to colchicine or nocodazole prior to neural fold formation. Exposure to these drugs prevented the anterior neural folds from closing. Neurulation however proceeded normally in the posterior regions of the embryo. We were unable to find apically constricted cells in the neural plate of colch...

Lung endothelial barrier function is regulated by multiple signaling pathways, including mitogen-activated protein kinases (MAPK) extracellular signal-regulated kinases (ERK) 1/2 and p38. We have recently shown involvement of microtubule (MT) disassembly in endothelial cell (EC) barrier failure. In this study, we examined potential involvement of ERK1/2 and p38 MAPK in lung EC barrier dysfuncti...

Microtubules are a primary cytoskeletal constituent of axons and growth cones. In addition to serving as a scaffolding for axon assembly, they also provide a means of transport of organelles that are essential for outgrowth and maintenance of synaptic function. Pharmacological manipulations that disrupt net assembly of microtubules also interfere with growth cone advance and axon extension. Les...

Inge Grundke-Iqbal and Khalid Iqbal found a connection between microtubule associated tau and Alzheimer's disease. They described that abnormally phosphorylated tau is a component of the paired helical filaments found in the disease. Afterwards they described that tau hyperphosphorylation prevents microtubule assembly. Now trying to complement the relationship between microtubules and tau phosp...

Speed and reliability of synaptic transmission are essential for information coding in neuronal networks and require the presence of clustered neurotransmitter receptors at the plasma membrane in precise apposition to presynaptic terminals. Receptor clusterization is the result of highly regulated processes involving functional and structural proteins. Among the structural elements, microtubule...

The organization of myosin in the fibroblast lamellum was studied by correlative fluorescence and electron microscopy after a novel procedure to reveal its underlying morphology. An X-rhodamine analog of conventional smooth muscle myosin (myosin II) that colocalized after microinjection with endogenous myosin was used to trace myosin distribution in living fibroblasts. Then, the same cells were...