Temporal association of $Ca^{2+}$-dependent protein kinase with oil bodies during seed development in Santalum album L.: Its biochemical characterization and significance

Anil, Veena S and Harmon, Alice C and Rao, Sankara K (2003) Temporal association of $Ca^{2+}$-dependent protein kinase with oil bodies during seed development in Santalum album L.: Its biochemical characterization and significance. In: Plant and Cell Physiology, 44 (4). pp. 367-376.

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Abstract

Calcium-dependent protein kinase (CDPK) is expressed in sandalwood (Santalum album L.) seeds under developmental regulation, and it is localized with spherical storage organelles in the endosperm [Anil et al. (2000) Plant Physiol. 122:1035]. This study identifies these storage organelles as oil bodies. A 55 kDa protein associated with isolated oil bodies, showed $Ca^{2+}$-dependent autophosphorylation and also cross-reacted with anti-soybean CDPK. The CDPK activity detected in the oil body-protein fraction was calmodulin-independent and sensitive to W7 (N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide) inhibition. Differences in Michaelis Menton kinetics, rate of histone phosphorylation and sensitivity to W7 inhibition between a soluble CDPK from embryos and the oil body-associated CDPK of endosperm suggest that these are tissue-specific isozymes. The association of CDPK with oil bodies of endosperm was found to show a temporal pattern during seed development. CDPK protein and activity, and the in vivo phosphorylation of Ser and Thr residues were detected strongly in the oil bodies of endosperm from maturing seed. Since oil body formation occurs during seed maturation, the observations indicate that CDPK and $Ca^{2+}$ may have a regulatory role during oil accumulation/oil body biogenesis. The detection of CDPK-protein and activity in oil bodies of groundnut, sesame, cotton, sunflower, soybean and safflower suggests the ubiquity of the association of CDPKs with oil bodies.

Item Type:	Journal Article
Publication:	Plant and Cell Physiology
Publisher:	Oxford University Press
Additional Information:	Copyright of this article belongs to Oxford University Press.
Keywords:	Calcium-signaling;CDPK;Oil bodies;Santalum album L;Seed development
Department/Centre:	Division of Biological Sciences > Biochemistry
Date Deposited:	20 Sep 2007
Last Modified:	19 Sep 2010 04:39
URI:	http://eprints.iisc.ac.in/id/eprint/11847

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