RpoN and the Nps and Npa two-component regulatory system control pilE transcription in commensal Neisseria.

María A Rendón,Beatriz Lona,Mancheong Ma,Magdalene So

doi:10.1002/mbo3.713

Abstract

Over 20 genes are involved in the biogenesis and function of the Neisseria Type IV pilus (Tfp). In the pathogenic species, RpoD and the integration host factor (IHF) protein regulate expression of pilE, encoding the Tfp structural subunit. We previously reported that in commensal species, pilE transcription is regulated by RpoN, IHF, and activator Npa. Npa has many hallmarks of response regulators in two‐component regulatory systems, leading us to search for its response regulator partner. We report that Npa partners with sensor kinase Nps to control pilE transcription. Among the genes involved in Tfp biogenesis and function, only pilE is controlled by RpoN and Npa/Nps. We summarize our findings in a model, and discuss the implications of the differential regulation of pilE the context of Neisseria Tfp biogenesis.

Highlights

The Type IV pilus (Tfp) is a multiprotein structure on the surface of many bacteria and archaea (Albers & Jarrell, 2015; Berry & Pelicic, 2015)
Since Npa has hallmarks of a response regulator, we searched the genome of commensal Neisseria elongata (Nel) for its sensor kinase (SK) counterpart, and found Open Reading Frame (ORF) (NEIELOOT_00058) whose deduced amino acid sequence has domains typically found in SK
We show that Neisseria pilus sensor (Nps) is required for pilE transcription, and that Nps and Npa act in concert as a two-component regulatory systems (TCRS)

Summary

| INTRODUCTION

The Type IV pilus (Tfp) is a multiprotein structure on the surface of many bacteria and archaea (Albers & Jarrell, 2015; Berry & Pelicic, 2015). RpoN regulation of pilE requires integration host factor (IHF) and an activator, Npa (Rendón et al, 2013). IHF enhances the efficiency of pilE transcription in both pathogenic and commensal Neisseria species, albeit by different mechanisms (Hill et al, 1997; Rendón et al, 2013). Since Npa has hallmarks of a response regulator, we searched the genome of commensal Neisseria elongata (Nel) for its SK counterpart, and found Open Reading Frame (ORF) (NEIELOOT_00058) whose deduced amino acid sequence has domains typically found in SK. We show that RpoN and Nps/Npa control transcription only of pilE and not the other Tfp biogenesis genes reported to date The implication of these different control mechanisms for Type IV pilus biogenesis is discussed

| EXPERIMENTAL PROCEDURES

D Receiver

| DISCUSSION