Fungal apoptosis: function, genes and gene function

Abstract

Cells of all living organisms are programmed to self-destruct under certain conditions. The most well known form of programmed cell death is apoptosis, which is essential for proper development in higher eukaryotes. In fungi, apoptotic-like cell death occurs naturally during aging and reproduction, and can be induced by environmental stresses and exposure to toxic metabolites. The core apoptotic machinery in fungi is similar to that in mammals, but the apoptotic network is less complex and of more ancient origin. Only some of the mammalian apoptosis-regulating proteins have fungal homologs, and the number of protein families is drastically reduced. Expression in fungi of animal proteins that do not have fungal homologs often affects apoptosis, suggesting functional conservation of these components despite the absence of protein-sequence similarity. Functional analysis of Saccharomyces cerevisiae apoptotic genes, and more recently of those in some filamentous species, has revealed partial conservation, along with substantial differences in function and mode of action between fungal and human proteins. It has been suggested that apoptotic proteins might be suitable targets for novel antifungal treatments. However, implementation of this approach requires a better understanding of fungal apoptotic networks and identification of the key proteins regulating apoptotic-like cell death in fungi.

The Calcineurin Pathway Inhibitor Tacrolimus Enhances the In Vitro Activity of Azoles against Mucorales via Apoptosis

“…Authors have also reported ROS-induced apoptosis in Aspergillus nidulans, Fusarium oxysporum, and Candida albicans cells (37)(38)(39). Sharon et al (40) reported that apoptotic pathways in fungi seem to be mitochondrion dependent, and mitochondria are considered to be a powerful source of superoxide radicals in miconazole-and farnesol-induced apoptosis (41). …”

Hyperthermia Sensitizes Rhizopus oryzae to Posaconazole and Itraconazole Action through Apoptosis

“…S2 in the supplemental material). As high temperatures induce both apoptosis and necrosis in mammalian cells (15), we sought to differentiate between apoptotic and necrotic R. oryzae cells by using the annexin V-FITC and PI double-staining method. In this method, apoptotic cells are stained with annexin V-FITC, whereas PI accumulates in the nuclei of necrotic cells via membrane permeabilization (34).…”

“…Various physiological stresses, ionizing radiation, and hyperthermia have been reported to trigger apoptosis in fungi and cancer cells (14)(15)(16). However, the precise mechanism of hyperthermia-induced apoptosis in mammalian cells is not clear.…”

“…Apoptosis has been observed in a number of filamentous fungi, such as Aspergillus nidulans, Aspergillus fumigatus, Neurospora crassa, and Fusarium oxysporum (12)(13)(14)(15). Various physiological stresses, ionizing radiation, and hyperthermia have been reported to trigger apoptosis in fungi and cancer cells (14)(15)(16).…”

Transcriptome changes initiated by carbon starvation in Aspergillus nidulans

“…Although necrotic cell death is possible during any kind of stress, programmed cell death processes have also been observed during carbon starvation in several fungi (Emri et al, 2005;Cebollero & Gonzalez, 2006;Robson, 2006;Pollack et al, 2009;Sharon et al, 2009). In the case of A. nidulans, the appearance of apoptotic markers (membrane inversion, DNA fragmentation) was detected in late autolytic cultures, and macroautophagy has also been observed in both carbon-starved and rapamycin-treated cultures by Emri et al (2005) and Kim et al (2011), respectively.…”