Study sheds new light on the mechanism of individual cell memory, using yeast as a model

A mnemon is aprotein that stores information in individual cells by forming stable super-assemblies. This memory state is passed on from one daughter cell to the next. When facing an uncommitted partner, budding yeast cells coalesce the G1/S inhibitor Whi3 into a dominant mnemon super-assembly that drives escape from the mate. This state is stable in the mother cell for many division cycles without being passed on to its daughters. It was not known how cells maintain and partition the state.

In a study published in Current Biology, researchers show that Whi3mnem is confined to the mother cell by ER-lateral barriers at the bud neck. When barriers are lifted, the self-templating fibrils in the embryo form a collective memory.

The authors conclude that the self-templating prion-like behavior of Whi3mnem is needed for the persistence of memory, and that its association with the ER prevents its infectious propagation to the daughter cells. The first mechanism for how cells can form and maintain individual memory was provided by these findings.

There is a question that naturally follows from the results: Are persistence and confinement conserved mechanisms for memory in organisms? The prion-like behavior of mnemons may be unleashed by age-related confinement defects, allowing them to spread in tissues and promote phenotypes very similar to those observed in neurodegenerative diseases.

More information: Yasmin Lau et al, Whi3 mnemon association with endoplasmic reticulum membranes confines the memory of deceptive courtship to the yeast mother cell, Current Biology (2022). DOI: 10.1016/j.cub.2022.01.002 Journal information: Current Biology Citation: Study sheds new light on the mechanism of individual cell memory, using yeast as a model (2022, May 16) retrieved 16 May 2022 from https://phys.org/news/2022-05-mechanism-individual-cell-memory-yeast.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.