TY - JOUR
T1 - Characterization and purification of a soluble protein controlling Ca-channel activity in paramecium
AU - Haga, Nobuyuki
AU - Forte, Michael
AU - Ramanathan, Rajeev
AU - Hennessey, Todd
AU - Takahashi, Mihoko
AU - Kung, Ching
PY - 1984/11
Y1 - 1984/11
N2 - The analysis of the voltage-sensitive Ca++ channel of the unicellular eucaryote, Paramecium has been extended to a biochemical level based on recent observations that the transfer of cytoplasm from wild-type cells into mutants lacking Ca++-channel function ("pawn" in P. tetraurelia and "CNR" in P. caudatum) causes mutant cells to regain Ca++-channel function. We have microinjected various cytoplasmic fractions into mutant cells and measured the restored Ca++-channel function using a convenient behavioral assay. Following the "curing" activity, we characterized and purified the component from wild-type cytoplasm that can restore the function missing in cells carrying mutations in the cnrC gene. The curing factor is not an RNA, but a heat-labile, -SH-containing protein that appears to affect existing mutant channels on the ciliary membrane. We have purified this factor over 500-fold from the soluble cytoplasm using conventional techniques. The protein is of low apparent molecular weight (<30,000 daltons), acidic, soluble, and does not have the properties of calmodulin.
AB - The analysis of the voltage-sensitive Ca++ channel of the unicellular eucaryote, Paramecium has been extended to a biochemical level based on recent observations that the transfer of cytoplasm from wild-type cells into mutants lacking Ca++-channel function ("pawn" in P. tetraurelia and "CNR" in P. caudatum) causes mutant cells to regain Ca++-channel function. We have microinjected various cytoplasmic fractions into mutant cells and measured the restored Ca++-channel function using a convenient behavioral assay. Following the "curing" activity, we characterized and purified the component from wild-type cytoplasm that can restore the function missing in cells carrying mutations in the cnrC gene. The curing factor is not an RNA, but a heat-labile, -SH-containing protein that appears to affect existing mutant channels on the ciliary membrane. We have purified this factor over 500-fold from the soluble cytoplasm using conventional techniques. The protein is of low apparent molecular weight (<30,000 daltons), acidic, soluble, and does not have the properties of calmodulin.
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U2 - 10.1016/0092-8674(84)90192-2
DO - 10.1016/0092-8674(84)90192-2
M3 - Article
C2 - 6091917
AN - SCOPUS:0021674199
VL - 39
SP - 71
EP - 78
JO - Cell
JF - Cell
SN - 0092-8674
IS - 1
ER -