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. 1985 Sep;79(1):28–33. doi: 10.1104/pp.79.1.28

Effect of Calmodulin Antagonists on Auxin-Induced Elongation 1

K G Raghothama 1, Yosef Mizrahi 1,2, B W Poovaiah 1
PMCID: PMC1074824  PMID: 16664387

Abstract

Coleoptile segments of oat (Avena sativa var Cayuse) and corn (Zea mays L. var Patriot) were incubated in different concentrations of calmodulin antagonists in the presence and absence of α-naphthaleneacetic acid. The calmodulin antgonists (chlorpromazine (CP), trifluoperazine, and fluphenazine) inhibited the auxin-induced elongation at 5 to 50 micromolar concentrations. Chlorpromazine sulfoxide, an analog of chlorpromazine, did not have significant effect on the elongation of oat and corn coleoptiles. A specific inhibitor of calmodulin N-(6-aminohexyl)5-chloro-1-naphthalenesulfonamide hydrochloride (W-7, a naphthalenesulfonamide derivative) inhibited coleoptile elongation, while its inactive analog N-(6-aminohexyl)-1-naphthalenesulfonamide hydrochloride (W-5) was ineffective at similar concentrations. During a 4-hour incubation period, coleoptile segments accumulated significant quantities of 3H-CP. About 85 to 90% of auxin-induced growth was recovered after 4 hours of preincubation with CP or 12 hours with W-7 and transferring coleoptiles to buffer containing NAA. Leakage of amino acids from coleoptiles increased with increasing concentration of CP, showing a rapid and significant increase above 20 micromolar CP. The amount of amino acids released in the presence of W-7 and W-5 was significantly lower than the amount released in the presence of CP. Both W-5 and W-7 increased amino acid release but only W-7 inhibited auxin-induced growth. Calmodulin activity measured by phosphodiesterase activation did not differ significantly between auxin-treated and control coleoptile segments. These results suggest the possible involvement of calmodulin in auxin-induced coleoptile elongation.

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Selected References

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  1. Anderson J. M., Cormier M. J. Calcium-dependent regulation of NAD kinase. Biochem Biophys Res Commun. 1978 Oct 16;84(3):595–602. doi: 10.1016/0006-291x(78)90747-7. [DOI] [PubMed] [Google Scholar]
  2. Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1006/abio.1976.9999. [DOI] [PubMed] [Google Scholar]
  3. Burris J. E., Black C. C. Inhibition of coral and algal photosynthesis by ca-antagonist phenothiazine drugs. Plant Physiol. 1983 Apr;71(4):712–715. doi: 10.1104/pp.71.4.712. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Charbonneau H., Cormier M. J. Purification of plant calmodulin by fluphenazine-Sepharose affinity chromatography. Biochem Biophys Res Commun. 1979 Oct 12;90(3):1039–1047. doi: 10.1016/0006-291x(79)91931-4. [DOI] [PubMed] [Google Scholar]
  5. Cheung W. Y. Calmodulin plays a pivotal role in cellular regulation. Science. 1980 Jan 4;207(4426):19–27. doi: 10.1126/science.6243188. [DOI] [PubMed] [Google Scholar]
  6. Elliott D. C., Batchelor S. M., Cassar R. A., Marinos N. G. Calmodulin-binding drugs affect responses to cytokinin, auxin, and gibberellic Acid. Plant Physiol. 1983 May;72(1):219–224. doi: 10.1104/pp.72.1.219. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Kubowicz B. D., Vanderhoef L. N., Hanson J. B. ATP-Dependent Calcium Transport in Plasmalemma Preparations from Soybean Hypocotyls : EFFECT OF HORMONE TREATMENTS. Plant Physiol. 1982 Jan;69(1):187–191. doi: 10.1104/pp.69.1.187. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Levin R. M., Weiss B. Specificity of the binding of trifluoperazine to the calcium-dependent activator of phosphodiesterase and to a series of other calcium-binding proteins. Biochim Biophys Acta. 1978 May 3;540(2):197–204. doi: 10.1016/0304-4165(78)90132-0. [DOI] [PubMed] [Google Scholar]
  9. Paliyath G., Poovaiah B. W. Calmodulin inhibitor in senescing apples and its physiological and pharmacological significance. Proc Natl Acad Sci U S A. 1984 Apr;81(7):2065–2069. doi: 10.1073/pnas.81.7.2065. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Poovaiah B. W., Leopold A. C. Deferral of leaf senescence with calcium. Plant Physiol. 1973 Sep;52(3):236–239. doi: 10.1104/pp.52.3.236. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Poovaiah B. W., Leopold A. C. Hormone-solute interactions in the lettuce hypocotyl hook. Plant Physiol. 1974 Sep;54(3):289–293. doi: 10.1104/pp.54.3.289. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Sasaki Y., Hidaka H. Calmodulin and cell proliferation. Biochem Biophys Res Commun. 1982 Jan 29;104(2):451–456. doi: 10.1016/0006-291x(82)90658-1. [DOI] [PubMed] [Google Scholar]
  13. Scharff O., Foder B. Effect of trifluoperazine, compound 48/80, TMB-8 and verapamil on the rate of calmodulin binding to erythrocyte Ca2+-ATPase. Biochim Biophys Acta. 1984 Apr 25;772(1):29–36. doi: 10.1016/0005-2736(84)90514-5. [DOI] [PubMed] [Google Scholar]
  14. Scherer G. F., Morré D. J. In vitro stimulation by 2,4-dichlorophenoxyacetic acid of an ATPase and inhibition of phosphatidate phosphatase of plant membranes. Biochem Biophys Res Commun. 1978 Sep 14;84(1):238–247. doi: 10.1016/0006-291x(78)90288-7. [DOI] [PubMed] [Google Scholar]
  15. Veluthambi K., Poovaiah B. W. Calcium-promoted protein phosphorylation in plants. Science. 1984 Jan 13;223(4632):167–169. doi: 10.1126/science.223.4632.167. [DOI] [PubMed] [Google Scholar]
  16. Watterson D. M., Iverson D. B., Van Eldik L. J. Rapid separation and quantitation of 3',5'-cyclic nucleotides and 5'-nucleotides in phosphodiesterase reaction mixtures using high-performance liquid chromatography. J Biochem Biophys Methods. 1980 Mar;2(3):139–146. doi: 10.1016/0165-022x(80)90021-4. [DOI] [PubMed] [Google Scholar]

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