Características y funcionamiento de los Sistemas de Dos Componentes de organismos procariotas y eucariotas

[摘要] Two-component systems (TCSs) are signaling circuits that allow both prokaryotic and eukaryotic organisms to detect environmental cues and respond to them in an adaptive way. These signal transduction systems, based on phosphoryl-group transfers between histidine and aspartate- containing sensor kinase and response regulator proteins, are characterized to be highly specific in order to assure an appropriate response to each particular condition. Although many TCSs co-exist in a bacterial cell, different mechanisms prevent cross phosphorylation events that could compromise such specificity. However, there are functional connections between different TCSs, called cross regulation, which allows cells to modulate a coordinated response to multiple signals. Curiously, TCSs of eukaryotic cells, although conserve some bacterial TCSs features, acquired new architectures and, sometimes, novel modes of action. In this review, in addition to describe the most important structural and functional characteristics of bacterial TCSs, we compare the TCS architecture of prokaryotes and eukaryotes, and discuss briefly the consequences of the differences on signaling specificity.

[学科分类] 生物技术

[关键词] Two component systems;phosphorylation;specificity;signaling