DesK is a Histidine Kinase that allows Bacillus subtilis to maintain lipid homeostasis in response to changes in the environment. It is located in the membrane, and has five transmembrane helices and a cytoplasmic catalytic domain. The transmembrane region triggers the phosphorylation of the catalytic domain as soon as the membrane lipids rigidify. In this research, we study how transmembrane inter-helical interactions contribute to signal transmission; we designed a coexpression system that allows studying in vivo interactions between transmembrane helices. By Alanine-replacements, we identified a group of polar uncharged residues, whose side chains contain hydrogen-bond donors or acceptors, which are required for the interaction with other DesK transmembrane helices; a particular array of H-bond- residues plays a key role in signaling, transmitting information detected at the membrane level into the cell to finally trigger an adaptive response.Fil: Almada, Juan Cruz. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Microbiología. Argentina.Fil: Bortolotti, Ana. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Microbiología. Argentina.Fil: Ruysschaert, Jean Marie. Université Libre de Bruxelles. Center for Structural Biology and Bioinformatics. Laboratory for the Structure and Function of Biological Membranes. Belgium.Fil: De Mendoza, Diego. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET). Argentina.Fil: Inda, María Eugenia. Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science. Research Laboratory of Electronics. Cambridge.Fil: Inda, María Eugenia. Massachusetts Institute of Technology. MIT Synthetic Biology Center. Cambridge.Fil:Cybulski, Larisa Estefanía. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Microbiología. Argentina.