O. Rogero et Fj. Tejedor, IMMUNOCHEMICAL CHARACTERIZATION AND DEVELOPMENTAL EXPRESSION OF SHAKER POTASSIUM CHANNELS FROM THE NERVOUS-SYSTEM OF DROSOPHILA, The Journal of biological chemistry, 270(43), 1995, pp. 25746-25751
We have raised antisera against recombinant peptides expressed from cD
NAs fragments common to all splicing variants generated at the Shaker
locus of Drosophila and used them as a tool to biochemically character
ize these channel proteins, This antisera succeeded in detecting the e
xpression of multiple Shaker potassium channels (Sh Kch), proteins wit
h variable molecular mass (65-85 kDa) and pi (5.5-7), Additionally, fo
r first time, specific Sh proteins of 40-45 kDa most probably correspo
nding to some of the so called short Sh cDNAs previously isolated by o
thers have been identified, Using genetic criteria, it has been determ
ined that at least a good part of this variety of proteins is generate
d by alternative splicing, Developmental experiments show a double wav
e of Sh Hch channel expression with a first pick at the third instar l
arvae stage, a minimum at the beginning of puparation, and the highest
plateau 36 h after hatching of adult flies, The pattern of Sh splice
variants changes dramatically throughout development. A detergent-resi
stant fraction with about 50% of Sh Kch which seems to be anchored to
submembranous structures has been found, Finally, other biochemical pr
operties of Sh Kch, like membrane fractionation and glycosylation, are
also described.