All of these studies employ molecular genetic, protein biochemistry, and microbial physiology techniques. An organism must sense and respond to changes in its environment. These changes often involve changes in gene expression. In addition, in response to low levels of a particular nutrient, a bacterium will breakdown intracellular reserves to maintain a nutrient supply for anabolic reactions. In cyanobacteria, one of the storage forms for nitrogen and sulfur is the light-harvesting complex.
Cyanobacteria use phycobiliproteins to absorb light energy.
Phycobiliproteins, along with several linker polypeptides, are assembled into phycobilisomes that transfer light energy into Photosystem II complexes. I am interested in how cyanobacteria sense changes in the nutrient status of their environment. We are screening mutant cells for additional genes involved in the cellular response to low nitrogen. The pictures show Synechococcus sp. In addition to the regulated degradation of the phycobilisome, nitrate deprivation of Synechococcus sp. strain PCC 7002 alters the expression pattern of several genes.