Development of a Highly Sensitive Luciferase-Based Reporter System To Study Two-Step Protein Secretion in Cyanobacteria
David A. Russo, Julie A. Z. Zedler, Fabian D. Conradi, Nils Schuergers, Poul Erik Jensen, Conrad W. Mullineaux, Annegret Wilde, Georg Pohnert
Abstract
Protein secretion allows bacteria to interact and communicate with the external environment. Secretion is also biotechnologically relevant, where it is often beneficial to target proteins to the extracellular space. Due to a shortage of quantitative assays, many aspects of protein secretion are not understood. Here, we introduce an NLuc-based secretion reporter in cyanobacteria. NLuc is highly sensitive and can be assayed rapidly and in small volumes. The NLuc reporter allowed us to clarify the role of type IVa pili in protein secretion and identify mutations that increase secretion yield. This study expands our knowledge of cyanobacterial secretion and offers a valuable tool for future studies of protein secretion systems in cyanobacteria.