Why do so few patients appeal against detention under section 2 of the Mental Health Act?

Abstract

<h3>Abstract</h3> In this report, we investigate the evolution of transcription factor NF-κB by examining its structure, activity, and regulation in two protists using phylogenetic, cellular, and biochemical techniques. In <i>Capsaspora owczarzaki</i> (<i>Co</i>), we find that full-length NF-κB has an N-terminal DNA-binding domain and a C-terminal Ankyrin (ANK) repeat inhibitory domain, and its DNA-binding activity is more similar to metazoan NF-κB rather than Rel proteins. As with mammalian NF-κB proteins, removal of the ANK repeats is required for <i>Co</i>-NF-κB to enter the nucleus, bind DNA, and activate transcription. However, C-terminal processing of <i>Co</i>-NF-κB is not induced by co-expression of IKK in human cells. Exogenously expressed <i>Co</i>-NF-κB localizes to the nucleus in <i>Co</i> cells. NF-κB mRNA and DNA-binding levels differ across three life stages of <i>Capsaspora</i>, suggesting distinct roles for NF-κB in these life stages. RNA-seq and GO analyses identify possible gene targets and biological functions of <i>Co</i>-NF-κB. We also show that three NF-κB-like proteins from the choanoflagellate <i>Acanthoeca spectabilis</i> (<i>As</i>) all consist of primarily the N-terminal conserved Rel Homology domain sequences of NF-κB, and lack C-terminal ANK repeats. All three <i>As</i>-NF-κB proteins constitutively enter the nucleus of human and Co cells, but differ in their DNA-binding and transcriptional activation activities. Furthermore, all three <i>As</i>-NF-κB proteins can form heterodimers, indicating that NF-κB diversified into multi-subunit families at least two times during evolution. Overall, these results present the first functional characterization of NF-κB in a taxonomic kingdom other than Animalia and provide information about the evolution and diversification of this biologically important transcription factor. <h3>Significance</h3> These results represent the first functional characterization of the biologically important transcription factor NF-κB in a taxonomic kingdom other than Animalia. As such, they provide information on the evolutionary origins and basal diversification of NF-κB outside of metazoans. These results suggest that NF-κB plays life stage-specific roles in <i>Capsaspora</i>, the closest unicellular ancestor to all metazoans. Finally, the analysis of three NF-κB proteins in a single choanoflagellate indicates that choanoflagellates have subclasses of NF-κBs, which can form heterodimers, suggesting that NF-κB subunit expansion and diversification has occurred at least twice in evolution.