Reverse Engineering of a Thermosensing Regulator Switch

• Published in: Journal of molecular biology 2019-03, Vol.431 (5), p.1016-1024
• Main Authors: Inda, María Eugenia, Vazquez, Daniela B., Fernández, Ariel, Cybulski, Larisa E.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Bacillus subtilis - metabolism; Bacterial Proteins - metabolism; Cell Membrane - metabolism; histidin-kinase; Histidine Kinase - metabolism; Hydrogen Bonding; Membrane Proteins - metabolism; Protein Binding - physiology; reverse engineer; serine zipper; Signal Transduction - physiology; Temperature; Thermosensing - physiology; transmembrane signaling
• ISSN: 0022-2836; 1089-8638
• DOI: 10.1016/j.jmb.2019.01.025

To address the mechanism of thermosensing and its implications for molecular engineering, we previously deconstructed the functional components of the bacterial thermosensor DesK, a histidine kinase with a five-span transmembrane domain that detects temperature changes. The system was first simplified by building a sensor that consists of a single chimerical transmembrane segment that retained full sensing capacity. Genetic and biophysical analysis of this minimal sensor enabled the identification of three modular components named determinants of thermodetection (DOTs). Here we combine and tune the DOTs to determine their contribution to activity. A transmembrane zipper represents the master DOT that drives a reversible and activating dimerization through the formation of hydrogen bonds. Our findings provide the mechanism and insights to construct a synthetic transmembrane helix based on a poly-valine scaffold that harbors the DOTs and regulates the activity. The construct constitutes a modular switch that may be exploited in biotechnology and genetic circuitry. •The mechanistic underpinnings of DesK thermosensing is under debate.•Three functional motifs located in the transmembrane domain, named determinants of thermosensing (DOTs), are critical for signaling.•Incorporation of DOTs in a single-transmembrane poly-valine scaffold allows for thermoregulation of gene expression.•The construct constitutes a modular switch that may be exploited in thermogenetics.