Dissection of the NUP107 nuclear pore subcomplex reveals a novel interaction with spindle assembly checkpoint protein MAD1 inCaenorhabditis elegans

• DOI: 10.1091/mbc.e11-11-0927
• Publication Date: 2012-01-12T04:12:58Z
• Authors: Eduardo Ródenas; Cristina González...; Cristina Ayuso; Peter Askjaer
• Keywords: Cell Nucleus; 0301 basic medicine; Embryo, Nonmammalian; Active Transport, Cell Nucleus; Cell Cycle Proteins; Articles; Spindle Apparatus; Protein Serine-Threonine Kinases; Nuclear Pore Complex Proteins; 03 medical and health sciences; Aurora Kinases; Animals; Aurora Kinase B; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Kinetochores

Nuclear pore complexes consist of several subcomplexes. The NUP107 complex is important for nucleocytoplasmic transport, nuclear envelope assembly, and kinetochore function. However, the underlying molecular mechanisms and the roles of individual complex members remain elusive. We report the first description of a genetic disruption of NUP107 in a metazoan. Caenorhabditis elegans NUP107/npp-5 mutants display temperature-dependent lethality. Surprisingly, NPP-5 is dispensable for incorporation of most nucleoporins into nuclear pores and for nuclear protein import. In contrast, NPP-5 is essential for proper kinetochore localization of NUP133/NPP-15, another NUP107 complex member, whereas recruitment of NUP96/NPP-10C and ELYS/MEL-28 is NPP-5 independent. We found that kinetochore protein NUF2/HIM-10 and Aurora B/AIR-2 kinase are less abundant on mitotic chromatin upon NPP-5 depletion. npp-5 mutants are hypersensitive to anoxia, suggesting that the spindle assembly checkpoint (SAC) is compromised. Indeed, NPP-5 interacts genetically and physically with SAC protein MAD1/MDF-1, whose nuclear envelope accumulation requires NPP-5. Thus our results strengthen the emerging connection between nuclear pore proteins and chromosome segregation.