The role of Aspartyl aminopeptidase (Ape4) in Cryptococcus neoformans virulence and authophagy

In order to survive and cause disease, microbial pathogens must be able to proliferate at the temperature of their infected host. We identified novel microbial features associated with thermotolerance in the opportunistic fungal pathogen Cryptococcus neoformans using a random insertional mutagenesis strategy, screening for mutants with defective growth at 37°C. Among several thermosensitive mutants, we identified one bearing a disruption in a gene predicted to encode the Ape4 aspartyl aminopeptidase protein. Ape4 metalloproteases in other fungi, including Saccharomyces cerevisiae, are activated by nitrogen starvation, and they are required for autophagy and the cytoplasm-to-vacuole targeting (Cvt) pathway. However, none have been previously associated with altered growth at elevated temperatures. We demonstrated that the C. neoformans ape4 mutant does not grow at 37°C, and it also has defects in the expression of important virulence factors such as phospholipase production and capsule formation. C. neoformans Ape4 activity was required for this facultative intracellular pathogen to survive within macrophages, as well as for virulence in an animal model of cryptococcal infection. Similar to S. cerevisiae Ape4, the C. neoformans GFP-Ape4 fusion protein co-localized with intracytoplasmic vesicles during nitrogen depletion. APE4 expression was also induced by the combination of nutrient and thermal stress. Together these results suggest that autophagy is an important cellular process for this microbial pathogen to survive within the environment of the infected host.

Medienart:

E-Artikel

Erscheinungsjahr:

2017

Erschienen:

2017

Enthalten in:

Zur Gesamtaufnahme - volume:12

Enthalten in:

PloS one - 12(2017), 5 vom: 25., Seite e0177461

Sprache:

Englisch

Beteiligte Personen:

Gontijo, Fabiano de Assis [VerfasserIn]
de Melo, Amanda Teixeira [VerfasserIn]
Pascon, Renata C [VerfasserIn]
Fernandes, Larissa [VerfasserIn]
Paes, Hugo Costa [VerfasserIn]
Alspaugh, J Andrew [VerfasserIn]
Vallim, Marcelo A [VerfasserIn]

Links:

Volltext

Themen:

EC 3.4.11.7
Fungal Proteins
Glutamyl Aminopeptidase
Journal Article
Virulence Factors

Anmerkungen:

Date Completed 11.09.2017

Date Revised 04.08.2023

published: Electronic-eCollection

Citation Status MEDLINE

doi:

10.1371/journal.pone.0177461

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM272241164