Phytochelatin synthase

Lee, S., Moon, J. S., Ko, T.-S., Petros, D., Goldsbrough, P. B., and Korhan, S. S., 2003b, Overexpression of Arabidopsis phytochelatin synthase paradoxically leads to hypersensitivity to cadmium stress, Plant Physiol. 131 656-663. 

In contrast to MT induction, the available evidence suggests that PC synthesis is not stimulated by direct transcriptional activation. PCs can be synthesised very rapidly (within 5 min) in response to metals entering the cells, even when protein synthesis is totally inhibited (Scheller et al., 1987 Robinson etal., 1988). Phytochelatin synthase thus appears to be a constitutive enzyme. Loeffler et al. (1989) have shown that, for the enzyme purified from Silene cucubalus, metal ion induction is a post-... 

Grill, E., Loeffler, S., Winnacker, E.-L. Zenk, M.H. (1989). Phytochelatins, the heavy metal-binding peptides of plants are synthesised from glutathione by a specific gamma-glutamyl cysteine dipeptidyl transpeptidase (phytochelatin synthase). Proceedings of the National Academy of Sciences (USA) 86, 6838-42. 

Maier, T., Yu, C., Kulleritz, G., and Clemens, S. (2003) Localization and functional characterization of metal-binding sites in phytochelatin synthases. Planta 218,... 

Li, Y., Dhankher, O.P., Carreira, L., Lee, D., Chen, A., Schroeder, J.I., Balish, R.S., Meagher, R.B. (2004). Overexpression of phytochelatin synthase in Arabidopsis leads to enhanced arsenic tolerance and cadmium hypersensitivity. Plant Cell Physiol. 45 1787-97. 

Singh, S., Lee, W., Dasilva, N.A., Mulchandani, A., Chen, W. (2008). Enhanced arsenic accumulation by engineered yeast cells expressing Arabidopsis thaliana phytochelatin synthase. Biotechnol. Bioeng. 99 333-40. 

He ZY, Li JC, Zhang HY, Ma M. Different effects of calcium and lanthanum on the expression of phytochelatin synthase gene and cadmium absorption in Lactuca sativa. Plant Sci 2005 168 309-18. 

Both plants and yeast are known to produce phytochelatins (PC ), peptide metal-binding ligands, in response to heavy metal (especially Cd2+) toxicity heavy metal ions activate the enzyme, PC synthase (PCS), which produces PC s from glutathione (GSH) see equation (7.1). 

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