title: Translocation from nuclei to cytoplasm is necessary for anti A-PCD activity and turnover of the Type II IAP BcBir1.
abstract: Type II inhibitors of apoptosis (IAPs) belong to a subgroup of IAP-related proteins. While IAPs are restricted to animals, Type II IAPs are found in other phyla, including fungi. BcBir1, a Type II IAP from Botrytis cinerea has anti apoptotic-like programmed cell death (A-PCD) activity, which is important for pathogenicity of this fungus. Here we report on the role of sub-cellular localization of BcBir1 in protein turnover and anti A-PCD activity. Expression of BcBir1 in Saccharomyces cerevisiae had no effect on sensitivity of the yeast cells to A-PCD-inducing conditions, whereas expression of a truncated N' part reduced sensitivity of the cells to these conditions. The full-length BcBir1 protein was detected only in the yeast nucleus, whereas the N' part was observed both in the nucleus and cytoplasm. In B. cinerea, BcBir1 was mainly nuclear under optimal conditions, whereas under A-PCD-inducing conditions it shuttled to the cytoplasm and then it was completely degraded. Collectively, our results show that anti A-PCD activity of BcBir1 occurs in the cytoplasm, the C' end mediates regulation of steady state level of BcBir1 in the nucleus, and the N' end mediates anti A-PCD activity as well as fast degradation of BcBir1 in the cytoplasm.
authors.affiliation: Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv, 69978, Israel.
authors.forename: Neta
authors.initials: N
authors.lastname: Shlezinger
authors.affiliation: Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv, 69978, Israel.
authors.forename: Maayan
authors.initials: M
authors.lastname: Israeli
authors.affiliation: Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv, 69978, Israel.
authors.forename: Elad
authors.initials: E
authors.lastname: Mochly
authors.affiliation: Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv, 69978, Israel.
authors.forename: Liat
authors.initials: L
authors.lastname: Oren-Young
authors.affiliation: Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv, 69978, Israel.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Zhu
authors.affiliation: Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv, 69978, Israel.
authors.forename: Amir
authors.initials: A
authors.lastname: Sharon
mesh_terms: D020816:Amino Acid Motifs; D017209:Apoptosis; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020171:Botrytis / Q000737:chemistry / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism*; D003593:Cytoplasm / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D021381:Protein Transport; D059748:Proteolysis
chemical_list: D001426:Bacterial Proteins