title: Is unconventional secretion inhibited during cell division by Cdk1 activity?
abstract: A process of unconventional secretion that is dependent on the Golgi stacking protein GRASP and multiple components of the autophagy machinery has recently been documented for several cytoplasmic and membrane protein. Classical secretion via the exocytic pathway is inhibited during cell division in animal cells, as key membrane compartments, particularly the Golgi, are disassembled and fragmented. The question as to whether unconventional secretion is likewise inhibited during mitosis has not been explored. This mode of secretion supposedly bypasses the Golgi. However, GRASP and Vps34 (a key autophagy protein) are both substrates of the cell cycle regulating cyclin-dependent kinase 1 (Cdk1), and their activities are apparently inhibited by Cdk1 phosphorylation. Is unconventional secretion therefore similarly inhibited during cell division like conventional secretion? The story may yet turn out to be more complicated.
authors.affiliation: Department of Biochemistry, Yong Loo Lin School of Medicine, National University Health System, NUS Graduate School of Integrative Sciences and Engineering, National University of Singapore, Singapore, Singapore. bchtbl@nus.edu.sg
authors.forename: Bor Luen
authors.initials: BL
authors.lastname: Tang
mesh_terms: D001343:Autophagy / Q000235:genetics*; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D002453:Cell Cycle; D002455:Cell Division; D058546:Class III Phosphatidylinositol 3-Kinases / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D008938:Mitosis; D010766:Phosphorylation
chemical_list: D002352:Carrier Proteins; D008565:Membrane Proteins; C410230:tamalin protein, human; D058546:Class III Phosphatidylinositol 3-Kinases; D016203:CDC2 Protein Kinase