Another way to move chromosomes.

A typical way of moving chromosomes is exemplified by mitotic segregation, in which the centromere is directly captured by spindle microtubules. In this study, we highlight another way of moving chromosomes remotely from outside the nucleus, which involves SUN and KASH domain nuclear envelope proteins. SUN and KASH domain protein families are known to connect the nucleus to cytoskeletal networks and play a role in migration and positioning of the nucleus. Recent studies in the fission yeast Schizossacharomyces pombe demonstrated an additional role for the SUN-KASH protein complex in chromosome movements. During meiotic prophase, telomeres are moved to rearrange chromosomes within the nucleus. The SUN-KASH protein complex located in the nuclear envelope is involved in this process. Telomeres are connected to the SUN protein on the nucleoplasmic side, and the dynein motor complex binds to the KASH protein on the cytoplasmic side. Telomeres are then moved along the nuclear envelope using cytoplasmic microtubules. These findings illustrate a general mechanism for transmitting a cytoskeletal driving force to chromosomes across the nuclear envelope.