ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Abstract: Plasma membrane proteolipid protein (PMPLP) synthesis was examined in embryonic rat neurons and neonatal rat glial cells during differentiation in culture. Glial cultures were treated with 1 mM N6,O2, dibutyryl cyclic adenosine monophosphate (dbcAMP) following confluency to induce differentiation, which resulted in the elaboration of long cellular processes. However, no changes in the biosynthetic level of PMPLP was observed during the differentiation of these cells. Neurons differentiated spontaneously in culture, forming cellular aggregates immediately following plating and elaborating a network of neurites over 7 days. The differentiation of neurons was accompanied by a sevenfold increase in PM-PLP synthesis with increases in biosynthetic rate observed betvyeen days 1 and 3 and between days 3 and 7 in culture. Ultrastructural examination of neurons indicated that the Golgi apparatus was also developing during this period of time, with an increase in both the number of lamellae and generation of vesicles. The transport of PM-PLP to the plasma membrane was therefore examined in neurons at day 7 in culture by pulse labeling experiments with monensin and colchicine. Monensin (1 μM) was found to inhibit the appearance of radiolabeled PM-PLP in the plasma membrane by 63%, indicating that a functional Golgi apparatus is required for transport of PM-PLP to its target membrane. Colchicine (125 μM) also inhibited the appearance of newly synthesized PM-PLP in the plasma membrane by 〉40%, suggesting that microtubules may also be required for PM-PLP transport to the plasma membrane.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1471-4159.1986.tb00668.x
