Cell December 2, 2025

An archaeal transcription factor bridges prokaryotic and eukaryotic regulatory paradigms

Volume 188, Issue 26, 24 December 2025, Pages 7366-7377.e30 Article An archaeal transcription factor bridges prokaryotic and eukaryotic regulatory paradigms Author links open overlay panel , https://doi.org/10.1016/j.cell.2025.10.036 Get rights and content Under a Creative Commons license Open access Highlights • AmzR is a transcriptional repressor of methylamine growth in Methanosarcina acetivorans • AmzR is a methylamine sensor • AmzR binds DNA only in the absence of methylamines via paired basic helices • AmzR homologs are widely distributed in methanogenic archaea Summary Archaeal transcription is a hybrid of eukaryotic and prokaryotic features: an RNA polymerase II (RNAPII)-like polymerase transcribes genes organized in circular chromosomes within cells devoid of a nucleus. Consequently, archaeal genomes are depleted of transcriptional regulators found in other domains of life. Here, we outline the discovery of a cryptic, archaea-specific family of ligand-binding regulatory transcription factors (TFs), called AmzR (archaeal metabolite-sensing zipper-like regulators). We identify AmzR using an evolution-based genetic screen and show that it is a repressor of methanogenic growth on methylamines in the archaeon Methanosarcina acetivorans. AmzR binds its target promoters as an oligomer using paired basic α-helices akin to eukaryotic leucine zippers. AmzR also binds methylamines, which reduces its DNA-binding affinity and allows it to function as a one-component system commonly found in prokaryotes, while containing a eukaryotic-like DNA-binding motif. The AmzR family of TFs are widespread in archaea and broaden the scope of innovations at the prokaryote-eukaryote interface. Graphical abstract Download: Download high-res image (174KB) Download: Download full-size image Keywords archaeamethanogenmethylaminesmethanogenesistranscriptional regulatortranscription factorrepressorone-component systembZIPbHLH 3 Lead contact © 2025 The Author(s). Published by Elsevier Inc.