The fission yeast nucleoporin Alm1 is required for proteasomal degradation of kinetochore components

• Published in: The Journal of cell biology Vol. 216; no. 11; pp. 3591 - 3608
• Main Authors: Salas-Pino, Silvia, Gallardo, Paola, Barrales, Ramón R, Braun, Sigurd, Daga, Rafael R
• Format: Journal Article
• Language: English
• Published: United States Rockefeller University Press 06-11-2017; The Rockefeller University Press
• Subjects: Anchors; Biodegradation; Carrier Proteins - genetics; Carrier Proteins - metabolism; Cell cycle; Cell Cycle Proteins - genetics; Cell Cycle Proteins - metabolism; Cell division; Centromeres; Chromatin; Chromosomal Proteins, Non-Histone - genetics; Chromosomal Proteins, Non-Histone - metabolism; Chromosome Segregation; Chromosomes, Fungal; Defects; Endopeptidases - genetics; Endopeptidases - metabolism; Genotype; Homeostasis; Kinetochores; Kinetochores - metabolism; Localization; Mutation; Nuclear Envelope - enzymology; Nuclear Envelope - genetics; Phenotype; Proteasome Endopeptidase Complex - metabolism; Proteasomes; Proteins; Proteolysis; Schizosaccharomyces - enzymology; Schizosaccharomyces - genetics; Schizosaccharomyces pombe Proteins - genetics; Schizosaccharomyces pombe Proteins - metabolism; Stoichiometry; Yeast
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.201612194

Kinetochores (KTs) are large multiprotein complexes that constitute the interface between centromeric chromatin and the mitotic spindle during chromosome segregation. In spite of their essential role, little is known about how centromeres and KTs are assembled and how their precise stoichiometry is regulated. In this study, we show that the nuclear pore basket component Alm1 is required to maintain both the proteasome and its anchor, Cut8, at the nuclear envelope, which in turn regulates proteostasis of certain inner KT components. Consistently,
-deleted cells show increased levels of KT proteins, including CENP-C
, spindle assembly checkpoint activation, and chromosome segregation defects. Our data demonstrate a novel function of the nucleoporin Alm1 in proteasome localization required for KT homeostasis.