Title: Encoding mechanical and chemical information in cell membrane organization:
a sensory engram

Speaker: Dr. Satyajit Mayor

Summary:
The surface of a eukaryotic cell interfaces with the external milieu constantly decoding signals in the
form of chemical and mechanical inputs. These cues are interpreted primarily by membrane
receptors which are embedded in the plasma membrane, a fluid matrix templated by an active
cortical actin meshwork. One such membrane receptor, the integrin receptor receives chemical
inputs in the form of the extracellular matrix, and mechanical signals from the physical environment.
Chemical cues activate intracellular signaling cascades whereas mechanical cues activate mechanotransducers.
By studying the mechano-chemical activation of integrin receptors Prof. Mayor’s group
found that the activation of these two pathways result in the creation of localized membrane
domains consisting of nanoclusters of GPI-anchored proteins and lipids, resembling active emulsions.
These membrane domains are generated by active processes involving acto-myosin stresses,
imprinting the membrane with unique patterns. They hypothesize that this enables the encoding of
the chemical and mechanical nature of the external milieu, resulting in the regulation of crucial
aspects of integrin receptor function such as cell spreading and migration. Thus, this ATP-fueled
membrane composite behaves as a mechano-responsive medium, serving to integrate chemical and
physical cues presented at the cell periphery for the regulation of cell physiology.
Following this seminar, we will have a small workshop at the same venue (16:00 – 16:40). Jitu will
talk about “The membrane of a living cell - an ATP-fueled fabric”.