Kinetochore microtubule stability is dependent on the integral nuclear membrane protein, Samp1

• We have previously shown that the transmembrane inner nuclear membrane protein, Samp1, localises to the mitotic spindle during metaphase, where it recruits γ-tubulin, which promotes spindle assembly by increasing the β-tubulin density. Samp1 depleted cells displayed signs of spindle destabilisation, such as increased spindle length, prolonged metaphase and chromosome mis-segregation. Here we show that Samp1 partially localise to cold resistant kinetochore fibres of the mitotic spindle. Posttranscriptional silencing of Samp1 decreased the number of kinetochore fibres and resulted in mis-aligned chromosomes, phenotypes that were rescued by Samp1YFP overexpression. We also show that Samp1 interacts with the Aurora B kinase and that Samp1 depletion increased the distribution of Aurora B in the metaphase plate and increased its activity. The effects of Samp1 on Aurora B increases our understanding of the kinetochore fibres and spindle stability.

Subject headings

NATURVETENSKAP  -- Biologi -- Cellbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Cell Biology (hsv//eng)

Keyword

Samp1

nuclear membrane

mitotic spindle

k-fiber

Aurora B

Chromosome mis-segregation

neurokemi med molekylär neurobiologi

Neurochemistry with Molecular Neurobiology

Publication and Content Type

vet (subject category)

ovr (subject category)