title: Phosphorylation of Beclin 1 by DAP-kinase promotes autophagy by weakening its interactions with Bcl-2 and Bcl-XL.
abstract: Beclin 1, an essential autophagic protein, is a BH3-only protein that binds Bcl-2 anti-apoptotic family members. The dissociation of Beclin 1 from the Bcl-2 inhibitors is essential for its autophagic activity, and therefore is tightly controlled. We recently revealed a novel phosphorylation-based mechanism by which death-associated protein kinase (DAPk) regulates this process. We found that DAPk phosphorylates Beclin 1 on T119, a critical residue within its BH3 domain, and thus promotes Beclin 1 dissociation from Bcl-X(L) and autophagy induction. Here we report that T119 phosphorylation also reduces the interaction between Beclin 1 and Bcl-2, in line with the high degree of structural homology between the BH3 binding pockets of Bcl-2 and Bcl-X(L) proteins. Our results reveal a new phosphorylation-based mechanism that reduces the interaction of Beclin 1 with its inhibitors to activate the autophagic machinery.
authors.affiliation: Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Einat
authors.initials: E
authors.lastname: Zalckvar
authors.forename: Hanna
authors.initials: H
authors.lastname: Berissi
authors.forename: Miriam
authors.initials: M
authors.lastname: Eisenstein
authors.forename: Adi
authors.initials: A
authors.lastname: Kimchi
mesh_terms: D051017:Apoptosis Regulatory Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D001343:Autophagy; D000071186:Beclin-1; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002460:Cell Line; D064550:Death-Associated Protein Kinases; D006801:Humans; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008954:Models, Biological; D010766:Phosphorylation; D010769:Phosphothreonine / Q000378:metabolism; D011485:Protein Binding; D051020:bcl-X Protein / Q000378:metabolism*
chemical_list: D051017:Apoptosis Regulatory Proteins; C491997:BECN1 protein, human; D000071186:Beclin-1; D008565:Membrane Proteins; D051020:bcl-X Protein; D010769:Phosphothreonine; D064550:Death-Associated Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases