Apoptotic-like programed cell death in fungi: the benefits in filamentous species

Abstract

Studies conducted in the early 1990s showed for the first time that Saccharomyces cerevisiae can undergo cell death with hallmarks of animal apoptosis. These findings came as a surprise, since suicide machinery was unexpected in unicellular organisms. Today, apoptosis in yeast is well-documented. Apoptotic death of yeast cells has been described under various conditions and S. cerevisiae homologs of human apoptotic genes have been identified and characterized. These studies also revealed fundamental differences between yeast and animal apoptosis; in S. cerevisiae apoptosis is mainly associated with aging and stress adaptation, unlike animal apoptosis, which is essential for proper development. Further, many apoptosis regulatory genes are either missing, or highly divergent in S. cerevisiae. Therefore, in this review we will use the term apoptosis-like programed cell death (PCD) instead of apoptosis. Despite these significant differences, S. cerevisiae has been instrumental in promoting the study of heterologous apoptotic proteins, particularly from human. Work in fungi other than S. cerevisiae revealed differences in the manifestation of PCD in single cell (yeasts) and multicellular (filamentous) species. Such differences may reflect the higher complexity level of filamentous species, and hence the involvement of PCD in a wider range of processes and life styles. It is also expected that differences might be found in the apoptosis apparatus of yeast and filamentous species. In this review we focus on aspects of PCD that are unique or can be better studied in filamentous species. We will highlight the similarities and differences of the PCD machinery between yeast and filamentous species and show the value of using S. cerevisiae along with filamentous species to study apoptosis.

The complexity of apoptotic cell death in mollusks: An update

“…Apoptosis, a type of programmed cell death process, is widely distributed in nature, including plants, fungi, single cell eukaryotes and animals [49,104,115,117,130]. This process occurs during development and aging, playing a homeostatic role in both vertebrates and invertebrates.…”

Meiotic viral attenuation through an ancestral apoptotic pathway

“…NUC1 function is similarly puzzling, as meiotic PCD is unperturbed in nuc1∆/∆ mutants beyond the absence of fragmented DNA (7). Indeed, although activated nuclease pathways that promote genome fragmentation accompany diverse forms of PCD in plants, animals, protists, and fungi, the adaptive purposes for this association are unclear (13)(14)(15).…”

Choose Your Own Adventure: The Role of Histone Modifications in Yeast Cell Fate

“…While PCD is clearly not required for tissue architecture in unicellular yeasts, it may act to eliminate old, damaged or nonreplicative cells, releasing nutrients to younger, replicative cells and promoting their survival [7, 89]. Interestingly, many filamentous fungi have more similar PCD mechanisms to animal cells than budding yeast, and PCD has frequently been observed to be important for pathogenic life cycles and the formation of multicellular-like structures in these organisms [90]. …”