Extended N-terminal region of the essential phosphorelay signaling protein Ypd1 fromCryptococcus neoformanscontributes to structural stability, phosphostability and binding of calcium ions

Abstract

Rapid response to external stimuli is crucial for survival and proliferation of microorganisms. Pathogenic fungi employ histidine-to-aspartate multistep phosphorelay systems to respond to environmental stress, progress through developmental stages and to produce virulence factors. Because these His-to-Asp phosphorelay systems are not found in humans, they are potential targets for the development of new antifungal therapies. Here we report the characterization of the histidine phosphotransfer (HPt) protein Ypd1 from the human fungal pathogen Cryptococcus neoformans. Results from this study demonstrate that CnYpd1 indeed functions as a phosphorelay protein in vitro, and that H138 is confirmed as the site of phosphorylation. We found that CnYpd1 exhibits unique characteristics in comparison to other histidine phosphotransfer proteins, such as an extended N-terminal amino acid sequence, which we find contributes to structural integrity, a longer phosphorylated life time and the ability to bind calcium ions.

A frameshift in Yersinia pestis rcsD alters canonical Rcs signalling to preserve flea-mammal plague transmission cycles

“…Indeed, wild type RcsD in E. coli produces low levels of a short phosphotransfer protein ( Rogov et al, 2004 ; Wall et al, 2020 ). HPt orphan proteins function as phosphate transfer components in multiple phosphorelay systems in numerous prokaryotes and eukaryotes ( Hérivaux et al, 2018 ; Kennedy et al, 2016 ; Mohanan et al, 2017 ; Valentini et al, 2016 ), and have evolved from larger phosphotransferase proteins containing multiple domains. The frameshift present in rcsD of Y. pestis may represent an ongoing evolutionary process generating an orphan HPt protein and consequently a new regulatory pathway.…”

A frameshift inYersinia pestis rcsDleads to expression of a small HPt variant that alters canonical Rcs signalling to preserve flea-mammal plague transmission cycles

“…Indeed, wild-type RcsD in E. coli produces low levels of a short phosphotransfer protein (Rogov et al, 2004; Wall et al, 2020). HPt orphan proteins function as phosphate transfer components in multiple phosphorelay systems in numerous prokaryotes and eukaryotes (Herivaux et al, 2018; Kennedy et al, 2016; Mohanan et al, 2017; Valentini et al, 2016), and have evolved from larger phosphotransferase proteins containing multiple domains. The frameshift present in rcsD of Y. pestis may represent an ongoing evolutionary process generating an orphan HPt protein and consequently a new regulatory pathway.…”

Predicted Functional and Structural Diversity of Receiver Domains in Fungal Two-Component Regulatory Systems

“…Experimental data on TCSs in pathogenic fungi are remarkably limited and generally phenomenological rather than mechanistic. Although fungal TCSs were discovered almost 30 years ago, we are aware of only four published studies exploring the biochemical properties of purified TCS proteins from fungal pathogens ( 47 – 50 ). We hope that this article will inspire new investigators to turn their attention to fungal TCSs.…”