title: Microtubule nucleation at the cis-side of the Golgi apparatus requires AKAP450 and GM130.
abstract: We report that microtubule (MT) nucleation at the Golgi apparatus requires AKAP450, a centrosomal gamma-TuRC-interacting protein that also forms a distinct network associated with the Golgi. Depletion of AKAP450 abolished MT nucleation at the Golgi, whereas depletion of the cis-Golgi protein GM130 led to the disorganisation of AKAP450 network and impairment of MT nucleation. Brefeldin-A treatment induced relocalisation of AKAP450 to ER exit sites and concomitant redistribution of MT nucleation capacity to the ER. AKAP450 specifically binds the cis-side of the Golgi in an MT-independent, GM130-dependent manner. Short AKAP450-dependent growing MTs are covered by CLASP2. Like for centrosome, dynein/dynactin complexes are necessary to anchor MTs growing from the Golgi. We further show that Golgi-associated AKAP450 has a role in cell migration rather than in cell polarisation of the centrosome-Golgi apparatus. We propose that the recruitment of AKAP450 on the Golgi membranes through GM130 allows centrosome-associated nucleating activity to extend to the Golgi, to control the assembly of subsets of MTs ensuring specific functions within the Golgi or for transporting specific cargos to the cell periphery.
authors.affiliation: Departamento de Señalización Celular, Centro Andaluz de Biología Molecular y Medicina Regenerativa, CABIMER-CSIC, Sevilla, Spain.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Rivero
authors.forename: Jesus
authors.initials: J
authors.lastname: Cardenas
authors.forename: Michel
authors.initials: M
authors.lastname: Bornens
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Rios
mesh_terms: D054758:A Kinase Anchor Proteins / Q000235:genetics / Q000378:metabolism*; D001324:Autoantigens / Q000235:genetics / Q000378:metabolism*; D020126:Brefeldin A / Q000378:metabolism; D002460:Cell Line; D002465:Cell Movement / Q000502:physiology; D018385:Centrosome / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism*; D000072159:Dynactin Complex; D004398:Dyneins / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology / Q000502:physiology; D006056:Golgi Apparatus / Q000378:metabolism*; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism*; D011500:Protein Synthesis Inhibitors / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D055213:Retinal Pigment Epithelium / Q000166:cytology
chemical_list: D054758:A Kinase Anchor Proteins; C119719:AKAP9 protein, human; D001324:Autoantigens; C497851:CLASP2 protein, human; D003598:Cytoskeletal Proteins; D000072159:Dynactin Complex; C097741:Golgin subfamily A member 2; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; D011500:Protein Synthesis Inhibitors; D034741:RNA, Small Interfering; D020126:Brefeldin A; D004398:Dyneins