In this paper, Alain Rahier and Francis Karst have identified six specific amino acids of the cyclopropylsterol-cycloisomerase from the plant sterol pathway that control its activity or substrate specificity, and are likely to be located in the substrate-binding domain of the active site.
In this paper, Jay Thelen and colleagues describe CPK (calcium-dependent protein kinase) preference for 14-3-3 substrates, novel 14-3-3 phosphorylation and CPK autophosphorylation sites, and discuss a functional role for 14-3-3 phosphorylation.
In this paper, David Hanke and colleagues have found that the potato gene StCKP1 encodes an enzyme interconverting two forms of the plant hormone CK (cytokinin), an activator of tuber development. They also show that StCKP1 is able to prolong dormancy in potato tubers; when tubers are chilled, the extra dormancy disappears.
In this paper, Ute Vothknecht and colleagues have identified stromal transketolase as a target of calcium-dependent phosphorylation. The phosphorylated Ser428 was found to be highly conserved in transketolases from vascular plants and to affect the substrate saturation kinetics of the enzyme, indicating a role for phosphorylation in the regulation of carbon allocation.