Immunolocalization of NblA, a protein involved in phycobilisome turnover, during heterocyst differentiation in cyanobacteria

In unicellular non-diazotrophic cyanobacteria, NblA is a small polypeptide required for phycobilisome degradation during macronutrient limitation. In the filamentous N2-fixing Tolypothrix sp., a nblA gene (nblAI) lies upstream of the cpeBA operon that encodes phycoerythrin apoproteins. Using a specific anti-NblAI antibody it was found that in strains of Tolypothrix sp. NblAI abundance increases under nitrogen-limiting conditions but the protein...