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
N1 - Funding Information:
We thank our colleagues for helpful drscussions and Mr. R. Burns for technical assrstance. Thus work was supported by Nationril Institutes of Health grant GM 22714 and grant Natronal Science Foundation grant BNS 82-16149 to C. K., NSF grant PCM 83-091 IO, a grant from Northeast Ohro Heart Assocration to M. F., NIH NSO6950 to T. H , and a postdoctoral fellowshrp from the Muscular Dystrophy Association, Inc., to R. R.
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 -