Genetics in pond scum – Synechocystis as a model organism for sHsp structure and function
To get at sHsp function in vivo, we have worked with Synechocystis sp. PCC6803. This single-celled cyanobacterium can be easily transformed and the entire genome sequence of ~3,200 genes is known. Synechocystis has a single sHsp gene, Hsp16.6, and deletion of this gene leads to a defect in growth at high temperature. We have used Synechocystis for structure and function studies by making mutations in the Hsp16.6 gene and testing their phenotype. We are also interested in defining the proteins that may be protected by Hsp16.6 in vivo, and have found that a specific subset of Synechocystis proteins are bound to Hsp16.6 following heat stress in vivo. The bound proteins can be released in the presence of other chaperones in an ATP-dependent fashion, suggesting they represent true in vivo substrates.