from Valerie A. Ray and Karen L. Visick writing in Two-Component Systems in Bacteria:

The symbiotic relationship between the marine bioluminescent bacterium Vibrio fischeri and its host, the Hawaiian bobtail squid Euprymna scolopes, depends upon the ability of the two partners to sense and respond to each other. V. fischeri colonizes a specialized squid organ called the light organ in three general stages: initiation, accommodation, and persistence. To respond to the different environments encountered during these stages of colonization, V. fischeri utilizes specialized two-component signal transduction systems to regulate processes such as biofilm formation, motility and chemotaxis, and luminescence. In this chapter, we discuss in detail the two component systems that regulate these processes and how they impact successful colonization of the squid host.

Further reading: Two-Component Systems in Bacteria

from Karen Schrecke, Anna Staroń and Thorsten Mascher writing in Two-Component Systems in Bacteria:

The cell envelope stress response (CESR) network monitors and maintains envelope integrity to counteract the damaging effects of cell wall antibiotics and membrane perturbating agents. Two-component systems (2CSs) involved in orchestrating CESR in Firmicutes bacteria (low G+C Gram-positive) are characterized by so-called intramembrane-sensing histidine kinases (IM-HKs). The N-terminal input domain of these proteins consists of two transmembrane helices with a very short extracellular linker of less than 20 amino acids, which is insufficient for stimulus perception. It was originally thought that these HKs sense their stimuli within the membrane interface. But subsequent studies identified accessory membrane proteins for all IM-HKs described so far. This chapter will specifically summarize the current state of knowledge on BceRS- and LiaRS-like 2CSs, which are ubiquitously distributed in Firmicutes bacteria. While BceRSAB-like systems represent antibiotic-specific detoxification modules, LiaFSR-like three-component systems mount more general CESR. These two types of systems are genetically and functionally linked to BceAB-like ABC transporters and LiaF-like membrane-anchored regulatory proteins, respectively, which play a crucial role in sensing envelope stress and transferring the information to the cognate HKs. Accordingly, BceS- and LiaS-like IM-HKs do not function as sensor proteins, but rather as signal transfer relays between the sensor and the cognate response regulators.

Further reading: Two-Component Systems in Bacteria

from writing in Two-Component Systems in Bacteria:

Further reading: Two-Component Systems in Bacteria

from Juan-Francisco Martín, Alberto Sola-Landa and Antonio Rodríguez-García writing in Two-Component Systems in Bacteria:

Two-component systems (TCS) play a very important role in the regulation of metabolism in Streptomyces species in response to different nutritional or environmental signals. Streptomyces are Gram-positive soil-dwelling filamentous bacteria with large genomes that have the ability to produce thousands of different secondary metabolites. Streptomyces genomes contain a large number of paired two-component systems (usually more than 70) and some additional orphan sensor kinases and response regulators. Several of these systems have been studied in detail in the model species Streptomyces coelicolor. Particular attention has been paid to the PhoR/PhoP and the orphan GlnR systems due to their relevance in the control of primary metabolism and secondary metabolite biosynthesis. The PhoP binding sequence in many phosphate regulated promoters is formed by 11 nucleotide direct-repeats. A cross-talk between PhoP and other global regulators such as AfsR or GlnR has been found. Other two-component systems, particularly AbsA1/AbsA2, also control antibiotic biosynthesis in S. coelicolor, while others control chitinase synthesis, stress responses or cellular differentiation. Finally, some orphan response regulators named atypical response regulators (e.g. RedZ in S. coelicolor and JadR1 in Streptomyces venezuelae) bind as ligands the final product of the antibiotic biosynthetic pathway and act as feedback regulators of the biosynthesis of these secondary metabolites.

Further reading: Two-Component Systems in Bacteria

from writing in Two-Component Systems in Bacteria:

Further reading: Two-Component Systems in Bacteria

from writing in Two-Component Systems in Bacteria:

Further reading: Two-Component Systems in Bacteria

from Daniela Keilberg, Stuart Huntley and Lotte Søgaard-Andersen writing in Two-Component Systems in Bacteria:

The Myxococcus xanthus lifecycle is characterized by many social interactions. In particular, M. xanthus forms cooperatively spreading colonies in the presence of nutrients and multicellular, spore-filled fruiting bodies in the absence of nutrients. Formation of both cellular patterns depends on two intact motility systems. Moreover, fruiting body formation depends on intercellular communication and temporally regulated gene expression. The M. xanthus genome encodes a staggering 272 putative proteins of two-component system and most aspects of the M. xanthus lifecycle are regulated by one or more of these proteins. Interestingly, many of the corresponding genes encoding two-component system proteins possess an unusual organization in complex genes clusters and as orphan genes. However, major strides have been made in our understanding of a large number of these proteins. Here, we focus on the function of well-studied proteins of two-component systems in motility and development in M. xanthus.

Further reading: Two-Component Systems in Bacteria