The heat shock response of Fusobacterium nucleatum

The heat‐shock response of the oral Gram‐negative bacterium Fusobacterium nucleatum was examined. Different strains of F. nucleatum were grown at 37°C, 42°C and 48°C in the presence of [35S]methionine. Cellular proteins synthesised after shifts to higher temperatures were analysed by SDS‐PAGE and autoradiography. Strains ATCC 10953, F1, F3 and Fev1 exhibited heat‐shock response, and major proteins were observed at 60, 70 and 90 kDa, but increased protein synthesis was also observed for other proteins. Immunoblot analysis, using a panel of antibodies directed to epitopes on different known heat‐shock proteins revealed cross‐reactive proteins, indicating homology between Escherichia coli, Mycobacterium leprae and F. nucleatum heat shock proteins.