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Heterogeneity of 14S and 30S dynein ATPase activities with respect to activation by calmodulin
Author(s) -
Blum Jacob J.,
Hayes A.,
Vanaman T.,
Schachat F. H.
Publication year - 1982
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.240190105
Subject(s) - calmodulin , dynein , dynein atpase , biology , atpase , biochemistry , tetrahymena , tris , biophysics , cilium , enzyme , microbiology and biotechnology , microtubule
Demembranated cilia of Tetrahymena pyriformis were extracted with KCl or Tris‐EDTA and the crude dyneins from each resolved by sucrose density gradient sedimentation into 14S‐K, 30S‐K, 14S‐E and 30S‐E dyneins, respectively. The calmodulin activation ratio (ATPase activity in presence of added calmodulin/ATPase activity in absence of added calmodulin) did not vary across the 30S dynein fractions regardless of the method of extraction nor did it vary across the 14S‐E region. However, in going from the “heavy” fractions to the “light” fractions of the 14S‐K region, it increased markedly. The concentration of calmodulin required for half‐maximal activation did not differ appreciably in the “light” versus the “heavy” fractions of the 14S‐K region, suggesting that the affinity for calmodulin does not vary in these fractions. SDS‐polyacrylamide gel electrophoresis studies showed the presence of several polypeptides that varied in a systematic fashion across the 14S‐K region and hence may be involved in regulating the sensitivity of 14S‐K dynein ATPase activity to added calmodulin.