Evidence against direct involvement of cyclic GMP or cyclic AMP in bacterial chemotactic signaling.
AUTOR(ES)
Tribhuwan, R C
RESUMO
Defects in phosphotransferase chemotaxis in cya and cpd mutants previously cited as evidence of a cyclic GMP or cyclic AMP intermediate in signal transduction were not reproduced in a study of chemotaxis in Escherichia coli and Salmonella typhimurium. In cya mutants, which lack adenylate cyclase, the addition of cyclic AMP was required for synthesis of proteins that were necessary for phosphotransferase transport and chemotaxis. However, the induced cells retained normal phosphotransferase chemotaxis after cyclic AMP was removed. Phosphotransferase chemotaxis was normal in a cpd mutant of S. typhimurium that has elevated levels of cyclic GMP and cyclic AMP. S. typhimurium crr mutants are deficient in enzyme III glucose, which is a component of the glucose transport system, and a regulator of adenylate cyclase. After preincubation with cyclic AMP, the crr mutants were deficient in enzyme II glucose-mediated transport and chemotaxis, but other chemotactic responses were normal. It is concluded that cyclic GMP does not determine the frequency of tumbling and is probably not a component of the transduction pathway. The only known role of cyclic AMP is in the synthesis of some proteins that are subject to catabolite repression.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=213526Documentos Relacionados
- Involvement of cyclic GMP in intracellular signaling in the chemotactic response of Escherichia coli.
- Dictyostelium discoideum lipids modulate cell-cell cohesion and cyclic AMP signaling.
- Immunocytochemical localization of cyclic GMP: Light and electron microscope evidence for involvement of neuroglia
- Effects of Bradykinin and Indomethacin on Cyclic GMP and Cyclic AMP in Lung Slices
- 3′:5′-Cyclic AMP-dependent 3′:5′-cyclic GMP accumulation in Dictyostelium discoideum