A CROSS-SPECIES ANALYSIS OF CELL WALL MECHANOSENSORS

Abstract

The cell wall (CW) protects fungal cells from various mechanical challenges making its integrity essential for cell survival. CW integrity is monitored by transmembrane sensors that activate downstream effectors to promote CW synthesis in response to injuries. Sensors of the WSC 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. In response to forces applied onto the CW, these extracellular domains promote force detection, sensor clustering and cell survival. Interestingly, Wsc sensors exhibit variations in domain sequence and size among different fungal species. To understand how these variations impact mechanosensing, we heterologously expressed Wsc sensors taken from S. cerevisiae and C. albicans, in the fission yeast S. pombe. Remarkably, we found that a subset of these foreign sensors could 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 influence mechanosensation. These findings reveal a high level of functional plasticity in fungal sensors, and identify tuneable modules that may regulate mechanosensing of various CWs. SIGNIFICANCE STATEMENTO_LICell Wall Mechanosensors of the WSC family are present in most fungi, but whether they can detect mechanical stimuli in a foreign cell wall of a distant fungal species is unknown. C_LIO_LIThe authors heterologously expressed Wsc sensors taken from S. cerevisiae and C. albicans in the fission yeast S. pombe and demonstrate that a subset of foreign sensors can probe mechanical stress in its Cell Wall. C_LIO_LIThis work highlights a remarkable plasticity in mechanosensors ability to detect mechanical stress in the Cell Wall and identifies domains involved in regulating mechanosensing. C_LI