Some molecular interactions on cell surfaces may have a memory that affects their future interactions, according to investigators at the Georgia Institute of Technology. They suggest that results of certain single-molecule research produced under the i.i.d. (independent and identically-distributed) assumption need to be re-examined.
Using a micropipette adhesion frequency assay, the team studied a number of receptor-ligand interactions. The sequence data analysis reportedly revealed examples in which an interaction observed in one test affected the outcome of a future test. Depending on the biological system, the effect could either increase or decrease the likelihood of a future interaction, according to the researchers.
For instance, interaction between T cell receptors and an antigen bound to major histocompatibility molecules showed positive correlation, with one increasing the likelihood of a future interaction, the investigators explain. Interaction between C-adherins exhibited the opposite behavior, with one reducing the likelihood of a future interaction. In a third system the scientists examined, the events appeared to be truly independent, with one interaction not affecting a future one.
The research will be published in the Proceedings of the National Academy of Sciences.