Bacterial SET domain proteins and their role in eukaryotic chromatin modification.

Raãºl Alvarez-Venegas

doi:10.3389/fgene.2014.00065

Abstract

It has been shown by many researchers that SET-domain containing proteins modify chromatin structure and, as expected, genes coding for SET-domain containing proteins have been found in all eukaryotic genomes sequenced to date. However, during the last years, a great number of bacterial genomes have been sequenced and an important number of putative genes involved in histone post-translational modifications (histone PTMs) have been identified in many bacterial genomes. Here, I aim at presenting an overview of SET domain genes that have been identified in numbers of bacterial genomes based on similarity to SET domains of eukaryotic histone methyltransferases. I will argue in favor of the hypothesis that SET domain genes found in extant bacteria are of bacterial origin. Then, I will focus on the available information on pathogen and symbiont SET-domain containing proteins and their targets in eukaryotic organisms, and how such histone methyltransferases allow a pathogen to inhibit transcriptional activation of host defense genes.

Highlights

In eukaryotic organisms, genomic DNA is packaged in the form of a complex structure known as chromatin
The question is, for what purpose? If we take into consideration that a microbe that forms chronic infections in a host or in a host lineage may evolve to conserve or even to benefit its host, as this will help to maintain its immediate ecological resource (Moran, 2006), we can only hypothesize that the bacterial SET protein might complement the array of posttranslational modifications of histones in the fungus in order to improve bacterial intracellular replication through regulation of its host gene expression, and most important for the fungus, to formation of sporangia and spores
Recent studies have found that microbes affect a diverse set of epigenetic factors such as DNA methylation, histone modifications, chromatin-associated complexes, and non-coding RNAs to alter chromatin structure and gene expression

Summary

Introduction

Genomic DNA is packaged in the form of a complex structure known as chromatin. I will focus on the available information on pathogen and symbiont SET-domain containing proteins and their targets in eukaryotic organisms, and how such histone methyltransferases allow a pathogen to inhibit transcriptional activation of host defense genes.

Results

Conclusion