A cross-species analysis of cell wall mechanosensors.

The cell wall (CW) protects fungal cells from various challenges, making its integrity essential for cell survival. CW integrity is monitored by transmembrane sensors that activate effectors to promote CW synthesis in response to injuries. Sensors of the WSC (Wall Surface Component) family are found in most fungi, and share a conserved architecture, with a cytoplasmic tail, a single transmembrane domain, and a long Serine Threonine Rich domain (STR) prolonged by a WSC domain, both embedded in the CW. These extracellular domains promote force detection in the CW, sensor clustering and cell survival. Interestingly, Wsc sensors exhibit variations in domain sequence and size among fungal species. To understand how these variations impact force detection, we expressed Wsc sensors taken from Saccharomyces cerevisiae and Candida albicans, in the fission yeast Schizosaccharomyces pombe. Remarkably, we found that a subset of these foreign sensors cluster at sites of CW compression, but that others failed, suggesting divergences in mechanosensing abilities. By swapping sensor domains, we demonstrate that both the cytoplasmic tail and STR domain influence sensor relocalization to sites of CW compression. These findings reveal a high level of functional plasticity in fungal sensors and identify tuneable modules that may regulate mechanosensing of various CWs.