The mammalian potassium channel KCa3.1, which is important for T- and B-cell activation, is inhibited by cytoplasmic copper, mediated by a histidine residue (His358) that is phosphorylated to activate the channel.
The molecular mechanism of switching between phosphotransferase- and phosphatase-competent states in histidine-kinases has been uncovered, through direct crystallographic observation of bona fide complexes between a histidine-kinase and its response regulator from Bacillus subtilise.
Genetic lesions that compromise the ribosome P-stalk implicate direct signalling from the ribosome to the translation initiation factor eIF2 kinase GCN2 in the cellular response to amino acid starvation.
The circadian clock of Synechococcus elongatus PCC7942 schedules the activity of the transcription factor RpaA, which controls key events in carbon metabolism that contribute to cell fitness in conditions mimicking the natural environment.
The Ras activator RasGRP1 that impacts Ras signals in immune cells, leukemias, and colorectal cancer, switches to an active conformation aided by a pH-sensitive histidine residue in a central location of the RasGRP1 molecule.