# The Schizosaccharomyces pombe nucleolar protein Nsk1 modulates rDNA silencing during interphase

## TL;DR

This study explores the role of the nucleolar protein Nsk1 in rRNA silencing in Schizosaccharomyces pombe.

## Contribution

The novel finding is that Nsk1 modulates rDNA silencing during interphase, a previously unknown nucleolar function.

## Key findings

- Nsk1 participates in rRNA silencing during interphase.
- Nsk1 does not affect rDNA segregation, transcription, or nucleolar organization.

## Abstract

Schizosaccharomyces pombe
Nsk1
acts at kinetochores during mitosis to prevent error-prone chromosome segregation and it is phosphoregulated by
Cdk1
. The
Clp1
/
Cdc14
protein phosphatase, to which
Nsk1
binds, reverses Cdk1-mediated phosphorylation of
Nsk1
during anaphase. During interphase,
Nsk1
localizes exclusively to the nucleolus and its function there is unknown. In this study, we examined whether
Nsk1
shares functions in the nucleolus with other known
Clp1
/
Cdc14
phosphatase substrates that localize there. We found that
Nsk1
participates in rRNA silencing but not rDNA segregation, rDNA transcription, or nucleolar organization.