Structural and functional characterization of Solanum lycopersicum phosphatidylinositol 3-kinase C2 domain.

Phosphatidylinositol 3-kinases (PI3Ks) are characterized by the presence of a C2 domain at the N-terminal end (class I, III); or at both the N-terminal and C-terminal ends (class II), sometimes including a Plextrin homology domain and/or a Ras domain. Plant PI3Ks are analogous to the class III mammalian PI3K. An N-terminal fragment (~170 aa) of the tomato PI3K regulatory domain including the C2 domain, was cloned and expressed in a bacterial system.

Biochemical basis for functional ingredient design from fruits.

Functional food ingredients (nutraceuticals) in fruits range from small molecular components, such as the secondary plant products, to macromolecular entities, e.g., pectin and cellulose, that provide several health benefits.

Microarray analysis of ripening-regulated gene expression and its modulation by 1-MCP and hexanal.

Hexanal, an inhibitor of phospholipase D, has been successfully applied for the pre- and post-harvest treatment of fruits, vegetables and flowers. Changes in gene expression induced by hexanal and the ethylene antagonist 1-MCP, were analyzed by microarray using TOM2 tomato oligo-array containing approximately 12 000 unigenes. Mature green tomato fruits were treated with 1-MCP and hexanal, RNA isolated after 10 days of storage, and labeled cDNA synthesized for microarray analysis.

Cloning, expression and functional characterization of the C2 domain from tomato phospholipase Dα.

C2 domains exist as highly conserved N-terminal or C-terminal calcium- and lipid-binding motifs comprising nearly 130 amino acids, responsible for recruiting proteins to the membrane during signal transduction. In this study, the sequence corresponding to the N-terminal 164 amino acids of a full length cDNA of phospholipase Dα from tomato fruit was cloned in pET28(b) vector and expressed in E. coli as a His-tagged protein.

Grape and wine polyphenols down-regulate the expression of signal transduction genes and inhibit the growth of estrogen receptor-negative MDA-MB231 tumors in nu/nu mouse xenografts.

The antitumor properties of the Merlot grape (and Merlot wine) polyphenols were evaluated in relation to their ability to modulate gene expression in developing tumors using an athymic nude mouse model transplanted with the estrogen receptor-negative MDA-MB231 cells. Groups of mice were fed a modified AIN 93G diet (Research Diets Inc, New Brunswick, NJ) with the experimental groups receiving 100 mg/kg body weight equivalent of polyphenols by gavage 3 times per week. After 1 week of acclimation and another week of polyphenol supplementation, MDA-MB231 cells were transplanted and the growth patterns of the tumors monitored.