Chemoreceptor Trg and osmosensor EnvZ of Escherichia coli share a common transmembrane organization but have essentially unrelated primary structures. We created a hybrid gene coding for a protein in which Trg contributed its periplasmic and transmembrane domains as well as a short cytoplasmic segment and EnvZ contributed its cytoplasmic kinase/phosphatase domain. Trz1 transduced recognition of...

Chemoreceptors transmit signals from the environment to the flagellar motors via a histidine kinase that controls the phosphorylation level of the effector protein CheY. The cytoplasmic domain of chemoreceptors is strongly conserved and consists of a long alpha-helical hairpin that forms, in the dimer, a coiled-coil four-helix bundle. Changes in this domain during evolution are characterized by...

ISHII, K. and ISHII, K. Degeneration in the Efferent Nerve Endings on the Chemoreceptor Cells of the Carotid Labyrinth after the Sympathetic Nerve Trunk Section. Tohoku J. exp. Med., 1973, 109 (4), 339-345-Using 9 toads , the sympathetic nerve trunk was cut near the jugular ganglion . In more than a half of efferent nerve endings on the chemoreceptor cells, morphological changes , which were co...

Many sensory systems involve multiple steps of signal amplification to produce a significant response. One such mechanism may be the clustering of transmembrane receptors. In bacterial chemotaxis, where a stoichiometric His-Asp phosphorelay from the kinase CheA to the response regulator CheY plays a central role, the chemoreceptors (methyl-accepting chemotaxis proteins) cluster together with Ch...

Motile bacteria follow gradients of attractant and repellent chemicals with high sensitivity. Their chemoreceptors are physically clustered, which may enable them to function as a cooperative array. Although native chemoreceptor molecules are typically transmembrane homodimers, they appear to associate through their cytoplasmic tips to form trimers of dimers, which may be an important architect...

The perception and processing of chemical signals from the environment is essential for any living systems and is most probably the first sense developed in life. This perspective discusses the physical limits of chemoreception and gives an overview on the receptor types developed during evolution to detect chemical signals from the outside world of an organism. It discusses the interaction of ...

Sensory signals regulate multiple developmental and behavioral circuits in C. elegans, providing a genetically tractable system in which to investigate the mechanisms underlying the acquisition and integration of sensory information. kin-29 mutants are defective in the expression of a set of chemoreceptor genes, and exhibit characteristics associated with altered sensory signaling, including in...

A cost-effective, highly compact, and versatile optoelectronic device constructed of two ordinary light emitting diodes compatible with optosensing films has been developed. This fibreless device containing chemoreceptor, semiconductor light source, and detector integrated in a miniaturized flow-through cell of low microliter internal volume works as a complete photometric chemical sensor suita...

In the chemotaxis of Escherichia coli, polar clustering of the chemoreceptors, the histidine kinase CheA, and the adaptor protein CheW is thought to be involved in signal amplification and adaptation. However, the mechanism that leads to the polar localization of the receptor is still largely unknown. In this study, we examined the effect of receptor covalent modification on the polar localizat...