title: LAP1 is a crucial protein for the maintenance of the nuclear envelope structure and cell cycle progression.
abstract: Cell division in eukaryotes requires the disassembly of the nuclear envelope (NE) at the beginning of mitosis and its reassembly at the end of mitosis. These processes are complex and involve coordinated steps where NE proteins have a crucial role. Lamina-associated polypeptide 1 (LAP1) is an inner nuclear membrane protein that has been associated with cell cycle events. In support of this role, LAP1 has been implicated in the regulation of the NE reassembly and assembly of the mitotic spindle during mitosis. In this study, we demonstrated that LAP1 intracellular levels vary during the cell cycle in SH-SY5Y cells, and that LAP1 is highly phosphorylated during mitosis. It is also clear that LAP1 co-localized with acetylated α-tubulin in the mitotic spindle and with γ-tubulin in centrosomes (main microtubule organizing center) in mitotic cells. Moreover, LAP1 knockdown resulted in decreased number of mitotic cells and decreased levels of acetylated α-tubulin (marker of microtubules stability) and lamin B1. Additionally, it was possible to determine that LAP1 is important for centrosome positioning near the NE. These findings place LAP1 at a key position to participate in the maintenance of the NE structure and progression of the cell cycle.
authors.affiliation: Neuroscience Laboratory, Health Sciences Department, Centre for Cell Biology, University of Aveiro, 3810-193, Aveiro, Portugal.
authors.forename: Mariana
authors.initials: M
authors.lastname: Santos
authors.forename: Patrícia
authors.initials: P
authors.lastname: Costa
authors.forename: Filipa
authors.initials: F
authors.lastname: Martins
authors.forename: Edgar F
authors.initials: EF
authors.lastname: da Cruz e Silva
authors.forename: Odete A B
authors.initials: OA
authors.lastname: da Cruz e Silva
authors.forename: Sandra
authors.initials: S
authors.lastname: Rebelo
mesh_terms: D002453:Cell Cycle; D002460:Cell Line; D018385:Centrosome / Q000378:metabolism; D050883:HSC70 Heat-Shock Proteins / Q000502:physiology*; D006801:Humans; D022101:Microtubule-Organizing Center / Q000378:metabolism; D009685:Nuclear Envelope / Q000378:metabolism* / Q000648:ultrastructure; D021381:Protein Transport; D014404:Tubulin / Q000378:metabolism
chemical_list: D050883:HSC70 Heat-Shock Proteins; C494371:HSPA8 protein, human; D014404:Tubulin