Structural and functional analyses of APG5 a gene involved in autophagy in yeast

doi:10.1016/0378-1119(96)00354-X

Gene

Volume 178, Issues 1–2, 1996, Pages 139-143

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Abstract

The APG5 gene of Saccharomyces cerevisiae was cloned from a yeast genomic library by complementation of autophagy defective phenotype of apg5-1 mutant. Structural analysis of the obtained genomic fragment showed that the APG5 gene encodes a novel hydrophilic protein of 294 amino-acid residues without apparent structural similarities to other proteins in the database. To examine its function, a null allele for APG5 (Δapg5) was constructed and introduced into yeast, Δapg5 cells germinated and grew normally in nutrient-rich condition, however, their viability reduced significantly upon the nutrient starvation. They were also shown to be defective in autophagy: they could not sequester autophagic bodies in the vacuole under nitrogen-starvation conditions. These phenotypes are identical to those found in the apg5-1 mutant. The lack of apparent phenotype in rich medium suggests that APG5 function is required only under nutrient starvation condition, however, Northern blot analysis showed that its expression levels remained unchanged after nutrient depletion.

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With the study of molecular basis of autophagy-related genes (ATG) in yeasts, it has now become routine to use genetic approaches to pinpoint precise events in differentiation and development that require the cellular autophagic machinery (Levine and Klionsky, 2004). In Saccharomyces cerevisiae, Atg5 is required for accumulating autophagic bodies in the vacuoles when grown on starvation medium containing phenylmethylsulfonyl fluoride (PMSF), and for surviving in nutrient starving conditions (Kametaka et al., 1996). In Trichoderma reesei, TrAtg5 is involved in the autophagic process, and the TrATG5 deletion mutant is sensitive to starvation conditions, with reduced conidiation and abnormal conidiophores (Liu et al., 2011).
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Citation Excerpt :
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Citation Excerpt :
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¹: Present address: Department of Life Science, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 226, Japan.

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Gene

Abstract

References (14)

Point mutations define a sequence flanking the AUG initiator codon that modulates translation by eukaryotic ribosomes

Cell

Isolation and characterization of autophagy-defective mutants of Saccharomyces cerevisiae

FEBS Lett.

The leader peptide of yeast gene CPA1 is essential for the translational repression of its expression

Cell

Nucleotide sequence of AMSI the structure gene of vacuolar alpha-mannosidase of Saccharomyces cerevisiae

Biochem. Biophys. Res. Commun.

Ultrastructural analysis of the autophagic process in yeast: detection of autophagosomes and their characterization

J. Cell Biol.

Application of high efficiency lithium acetate transformation of intact yeast cells using single-stranded nucleic acids as carrier

Yeast

Ordered deletion for DNA sequencing and in vitro mutagenesis by polymerase extension and exonuclease III gapping of circular templates

Nucleic Acids Res.

Cited by (96)

Dual Function of USP14 Deubiquitinase in Cellular Proteasomal Activity and Autophagic Flux

Horning cell self-digestion: Autophagy wins the 2016 Nobel Prize in Physiology or Medicine

An autophagy gene, HoATG5, is involved in sporulation, cell wall integrity and infection of wounded barley leaves

Interplay between sumoylation and phosphorylation for protection against α-synuclein inclusions

Role of autophagy in cisplatin resistance in ovarian cancer cells

Glucose starvation inhibits autophagy via vacuolar hydrolysis and induces plasma membrane internalization by down-regulating recycling