Tw. Ecay et al., NONMUSCLE MYOSIN IIA COPURIFIES WITH CHLORIDE CHANNEL-ENRICHED MEMBRANES FROM EPITHELIA, Biochemical and biophysical research communications, 231(2), 1997, pp. 369-372
Hydrophobic affinity chromatography can be used to isolate, from bovin
e tracheal epithelial cells, an intracellular membrane vesicle fractio
n enriched in a single type of chloride channel. The intracellular ori
gin of these vesicles and the function of this chloride channel has no
t been established. As a first step in this direction, we have purifie
d a 200 kDa protein that copurifies with these membranes. Partial amin
o acid sequencing and immunoblotting with specific antibodies identify
this protein as nonmuscle myosin IIA. Since the vesicle chloride chan
nel is present in plasma membrane fractions as well, we hypothesize th
at these vesicles represent an intracellular storage or recycling comp
artment for epithelial chloride channels, which translocate to the pla
sma membrane during periods of peak demand for epithelial fluid secret
ion. (C) 1997 Academic Press.