Novel insights into DAPK autophagic signalling using peptide aptamer combinatorial protein-interaction screens.
DAPK represents a relatively unique enzyme in the protein kinase superfamily whose major biological functions are linked to both autophagy and signal-mediated apoptosis. However, genetic studies have not yet uncovered how DAPK integrates into the core autophagy-related (Atg) machinery since DAPK is not present in a genetically tractable eukaryotic cell such as yeast. Furthermore, there have been no definitive DAPK binding proteins identified in metazoan systems that play a direct role in cooperating with DAPK in autophagy. We have utilized a growing concept in systems biology that invokes linear peptide-motifs as a fundamental mechanism driving protein-protein interactions and as a key switch underlying the dynamics of a signal transduction pathway. By using peptide combinatorial libraries as an assay that reflects the diversity of the linear peptide motif repertoire in the mammalian proteome, we identified microtubule-associated protein 1B (MAP1B) as a novel DAPK interacting protein that stimulates DAPK-dependent membrane blebbing and autophagy. MAP1B has previously been shown to form a functional interaction with the autophagosomal protein Atg8 (LC3). Together these studies define a genetic interaction between DAPK-MAP1B in the regulation of autophagy that may have particular relevance to cellular signalling pathways that regulate cell survival or cell death under distinct environmental stresses.
Stevens
Craig
C
University of Edinburgh, Institute of Genetics and Molecular Medicine, Division of Cancer Biology, CRUK p53 Signal Transduction Group, Edinburgh, Scotland, UK. craig.stevens@ed.ac
Hupp
Ted R
TR
D020816:Amino Acid Motifs; D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism*; D052158:Aptamers, Peptide / Q000235:genetics / Q000378:metabolism*; D001343:Autophagy / Q000502:physiology*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D064550:Death-Associated Protein Kinases; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D011485:Protein Binding; D025941:Protein Interaction Mapping / Q000379:methods*; D015398:Signal Transduction / Q000502:physiology*
D051017:Apoptosis Regulatory Proteins; D052158:Aptamers, Peptide; D008869:Microtubule-Associated Proteins; C085284:microtubule-associated protein 1B; D064550:Death-Associated Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases