Regulation of interaction between signaling protein CheY and flagellar motor during bacterial chemotaxis

Abstract

This chapter describes the regulation of interaction between the signaling protein CheY and flagellar motor during bacterial chemotaxis. This chapter discusses the regulation of the interaction between two key players in the signal transduction pathway in bacterial chemotaxis: the protein CheY and the “switch” at the base of the flagellar motor. One of the major modes of communication between a cell and its environment is by chemotaxis— namely, by attraction to some chemicals and repulsion from others. The interaction of CheY with the switch, a key step in signal transduction during chemotaxis, may be regulated in a number of ways. CheY phosphorylation is an established mechanism of regulation, but the experimental results indicate that this alone is not sufficient. AcAMP, Ac∼P, Ca 2+ , fumarate, and perhaps additional compounds may be involved in the regulation. AcAMP causes an additional chemical modification of CheY— that is, acetylation; the mechanism of the function of fumarate is not known. It is reasonable to assume that while the phosphorylation activates CheY to bind to the switch, CheY causes it to detach from the switch; the acetylation and the fumarate affect switching step(s) subsequent to the binding.