title: AKAP95 interacts with nucleoporin TPR in mitosis and is important for the spindle assembly checkpoint.
abstract: Faithful chromosome segregation during mitosis relies on a proofreading mechanism that monitors proper kinetochore-microtubule attachments. The spindle assembly checkpoint (SAC) is based on the concerted action of numerous components that maintain a repressive signal inhibiting transition into anaphase until all chromosomes are attached. Here we show that A-Kinase Anchoring Protein 95 (AKAP95) is necessary for proper SAC function. AKAP95-depleted HeLa cells show micronuclei formed from lagging chromosomes at mitosis. Using a BioID proximity-based proteomic screen, we identify the nuclear pore complex protein TPR as a novel AKAP95 binding partner. We show interaction between AKAP95 and TPR in mitosis, and an AKAP95-dependent enrichment of TPR in the spindle microtubule area in metaphase, then later in the spindle midzone area. AKAP95-depleted cells display faster prometaphase to anaphase transition, escape from nocodazole-induced mitotic arrest and show a partial delocalization from kinetochores of the SAC component MAD1. Our results demonstrate an involvement of AKAP95 in proper SAC function likely through its interaction with TPR.
authors.affiliation: a Department of Molecular Medicine, Faculty of Medicine , University of Oslo , Oslo , Norway.|b Norwegian Center for Stem Cell Research, Oslo University Hospital , Oslo , Norway.
authors.forename: Graciela
authors.initials: G
authors.lastname: López-Soop
authors.affiliation: a Department of Molecular Medicine, Faculty of Medicine , University of Oslo , Oslo , Norway.|b Norwegian Center for Stem Cell Research, Oslo University Hospital , Oslo , Norway.
authors.forename: Torunn
authors.initials: T
authors.lastname: Rønningen
authors.affiliation: c Department of Oral Biology, Faculty of Dentistry , University of Oslo , Oslo , Norway.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Rogala
authors.affiliation: a Department of Molecular Medicine, Faculty of Medicine , University of Oslo , Oslo , Norway.
authors.forename: Nina
authors.initials: N
authors.lastname: Richartz
authors.affiliation: a Department of Molecular Medicine, Faculty of Medicine , University of Oslo , Oslo , Norway.
authors.forename: Heidi Kiil
authors.initials: HK
authors.lastname: Blomhoff
authors.affiliation: d Department of Biosciences, Faculty of Mathematics and Natural Sciences , University of Oslo , Oslo , Norway.
authors.forename: Bernd
authors.identifier: http://orcid.org/0000-0002-2804-9522
authors.initials: B
authors.lastname: Thiede
authors.affiliation: a Department of Molecular Medicine, Faculty of Medicine , University of Oslo , Oslo , Norway.|b Norwegian Center for Stem Cell Research, Oslo University Hospital , Oslo , Norway.
authors.forename: Philippe
authors.initials: P
authors.lastname: Collas
authors.affiliation: c Department of Oral Biology, Faculty of Dentistry , University of Oslo , Oslo , Norway.
authors.forename: Thomas
authors.initials: T
authors.lastname: Küntziger
mesh_terms: D054758:A Kinase Anchor Proteins / Q000235:genetics*; D020090:Chromosome Segregation / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D059566:M Phase Cell Cycle Checkpoints / Q000235:genetics*; D008938:Mitosis / Q000235:genetics; D022022:Nuclear Pore / Q000235:genetics / Q000378:metabolism; D028861:Nuclear Pore Complex Proteins / Q000235:genetics* / Q000378:metabolism; D011485:Protein Binding; D040901:Proteomics; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D008941:Spindle Apparatus / Q000235:genetics / Q000378:metabolism
chemical_list: D054758:A Kinase Anchor Proteins; C485099:AKAP8 protein, human; D028861:Nuclear Pore Complex Proteins; D011518:Proto-Oncogene Proteins; C073597:TPR protein, human
keywords: mitotic arrest deficient; translocated in promoter region