Mix and match: Patchwork domain evolution of the land plant-specific Ca2+-permeable mechanosensitive channel MCA.

Kanae Nishii,Hidetoshi Iida,Michael Möller,Berthold Heinze

doi:10.1371/journal.pone.0249735

Kanae Nishii, Hidetoshi Iida + Show 2 more

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https://doi.org/10.1371/journal.pone.0249735

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Abstract

Multidomain proteins can have a complex evolutionary history that may involve de novo domain evolution, recruitment and / or recombination of existing domains and domain losses. Here, the domain evolution of the plant-specific Ca2+-permeable mechanosensitive channel protein, MID1-COMPLEMENTING ACTIVITY (MCA), was investigated. MCA, a multidomain protein, possesses a Ca2+-influx-MCAfunc domain and a PLAC8 domain. Profile Hidden Markov Models (HMMs) of domains were assessed in 25 viridiplantae proteomes. While PLAC8 was detected in plants, animals, and fungi, MCAfunc was found in streptophytes but not in chlorophytes. Full MCA proteins were only found in embryophytes. We identified the MCAfunc domain in all streptophytes including charophytes where it appeared in E3 ubiquitin ligase-like proteins. Our Maximum Likelihood (ML) analyses suggested that the MCAfunc domain evolved early in the history of streptophytes. The PLAC8 domain showed similarity to Plant Cadmium Resistance (PCR) genes, and the coupling of MCAfunc and PLAC8 seemed to represent a single evolutionary event. This combination is unique in MCA, and does not exist in other plant mechanosensitive channels. Within angiosperms, gene duplications increased the number of MCAs. Considering their role in mechanosensing in roots, MCA might be instrumental for the rise of land plants. This study provides a textbook example of de novo domain emergence, recombination, duplication, and losses, leading to the convergence of function of proteins in plants.

Highlights

Proteins are essential components in any biological organism, including plants
The MCA functional (MCAfunc) domain was only present in streptophytes, whereas the PLAC8 domain was found in all proteomes examined in this study (Table 1)
Since MID1-COMPLEMENTING ACTIVITY (MCA) is a multidomain protein, we studied the phylogenetic relationships of the domains MCAfunc and PLAC8 separately

Summary

Introduction

Proteins are essential components in any biological organism, including plants. Each protein can be assembled from smaller units, termed domains, and a protein can consist of a single or multiple domains [1]. There exist several databases for the repository of protein domains found in biological organisms [2]. Protein domains can combine and evolve de novo. These de novo domains can be further combined with other de novo or existing domains to create novel proteins [1]. During plant evolution, it has been suggested

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