Receiver domain of sensor histidine kinase CKI1: Difference between revisions
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'''CKI1 as member of Multistep phosphorelay signaling in ''Arabidopsis''''' | '''CKI1 as member of Multistep phosphorelay signaling in ''Arabidopsis''''' | ||
The sensor histidine kinase CKI1 was identified as an activator of a cytokinin-like response when overexpressed in hypocotyl explants | The sensor histidine kinase CKI1 was identified as an activator of a cytokinin-like response when overexpressed in hypocotyl explants <ref>PMID:8875940</ref> and it is essential for the female gametophyte development (Hejatko, Pischke). Cytokinin response in ''Arabidopsis'' involves shoot and root growth regulation, leaf senesce, circadian rhythms etc. No cytokinin binding to CKI1 has been detected, and in contrast to the genuine cytokinin receptors of ''Arabidopsis'', CKI1 was found to be constitutively active in bacteria and yeast or ''Arabidopsis'' protoplasts (Yamada et al., 2001; Hwang & Sheen, 2001). | ||
Cytokinin signalling in plants is triggered by MSP, which was adopted by plants from bacterial Two-component system (citace). The signalling molecule is bound to the sensory histidin-kinase and then is transferred via AHPs (AHP1-AHP5) to nuclear response regulators (ARRs). ARRs act as transcription factors or interact with other effector proteins (citace) to perform specific cellular response to initial environmental stimuli. In contrast to ancestral two-component signalling in bacteria, protein interactions in plant MSP are supposed to be rather nonspecific. The current MSP interaction maps from ''Arabidopsis'' are based on yeast two-hybrid system (Urao et al., 2000; Tanaka et al., 2004; Dortay et al., 2006; Dortay et al., 2008) and show the AHPs as highly promiscuous, able to interact with all cytokinin receptors, number of other histidine-kinases and number of ARRs. | Cytokinin signalling in plants is triggered by MSP, which was adopted by plants from bacterial Two-component system (citace). The signalling molecule is bound to the sensory histidin-kinase and then is transferred via AHPs (AHP1-AHP5) to nuclear response regulators (ARRs). ARRs act as transcription factors or interact with other effector proteins (citace) to perform specific cellular response to initial environmental stimuli. In contrast to ancestral two-component signalling in bacteria, protein interactions in plant MSP are supposed to be rather nonspecific. The current MSP interaction maps from ''Arabidopsis'' are based on yeast two-hybrid system (Urao et al., 2000; Tanaka et al., 2004; Dortay et al., 2006; Dortay et al., 2008) and show the AHPs as highly promiscuous, able to interact with all cytokinin receptors, number of other histidine-kinases and number of ARRs. | ||
Recently was shown that CKI1RD is responsible for a specific interaction with individual subset of second messengers from AHP family (AHP2, AHP3, AHP5) (Pekárová et al, 2011). | Recently was shown that CKI1RD is responsible for a specific interaction with individual subset of second messengers from AHP family (AHP2, AHP3, AHP5) (Pekárová et al, 2011). | ||