Lipoxygenase Activity Accelerates Programmed Spore Germination in Aspergillus fumigatus

Frontiers in Microbiology. 2017;8 DOI 10.3389/fmicb.2017.00831

 

Journal Homepage

Journal Title: Frontiers in Microbiology

ISSN: 1664-302X (Online)

Publisher: Frontiers Media S.A.

LCC Subject Category: Science: Microbiology

Country of publisher: Switzerland

Language of fulltext: English

Full-text formats available: PDF, HTML, ePUB, XML

 

AUTHORS


Gregory J. Fischer (Department of Genetics, University of Wisconsin–Madison, MadisonWI, USA)

William Bacon (Department of Medical Microbiology and Immunology, University of Wisconsin–Madison, MadisonWI, USA)

Jun Yang (Department of Entomology and Nematology and Comprehensive Cancer Center, University of California, Davis, DavisCA, USA)

Jonathan M. Palmer (Department of Medical Microbiology and Immunology, University of Wisconsin–Madison, MadisonWI, USA)

Taylor Dagenais (Department of Medical Microbiology and Immunology, University of Wisconsin–Madison, MadisonWI, USA)

Bruce D. Hammock (Department of Entomology and Nematology and Comprehensive Cancer Center, University of California, Davis, DavisCA, USA)

Nancy P. Keller (Department of Medical Microbiology and Immunology, University of Wisconsin–Madison, MadisonWI, USA)

EDITORIAL INFORMATION

Blind peer review

Editorial Board

Instructions for authors

Time From Submission to Publication: 14 weeks

 

Abstract | Full Text

The opportunistic human pathogen Aspergillus fumigatus initiates invasive growth through a programmed germination process that progresses from dormant spore to swollen spore (SS) to germling (GL) and ultimately invasive hyphal growth. We find a lipoxygenase with considerable homology to human Alox5 and Alox15, LoxB, that impacts the transitions of programmed spore germination. Overexpression of loxB (OE::loxB) increases germination with rapid advance to the GL stage. However, deletion of loxB (ΔloxB) or its signal peptide only delays progression to the SS stage in the presence of arachidonic acid (AA); no delay is observed in minimal media. This delay is remediated by the addition of the oxygenated AA oxylipin 5-hydroxyeicosatetraenoic acid (5-HETE) that is a product of human Alox5. We propose that A. fumigatus acquisition of LoxB (found in few fungi) enhances germination rates in polyunsaturated fatty acid-rich environments.