The tethering of telomeres to the inner membrane of the nuclear envelope facilitates the pairing, recombination and synapsis of homologous chromosomes during meiotic prophase I in most organisms. Telomere attachment to the nuclear envelope is mediated by several nuclear envelope components, including the evolutionarily conserved SUN-domain-containing proteins and the KASH-domain proteins. Now (p. 88), José Suja and colleagues describe a key role for cyclin-dependent kinase 2 (CDK2) in regulating the integrity of the meiotic nuclear envelope. Using Cdk2−/− mouse spermatocytes, the authors demonstrate that the proteins SUN1, KASH5 and lamin C2 arrange into cap-like structures polarized at the nuclear envelope region facing the centrosome. Further testing revealed that, in vitro, SUN1 is a substrate for mouse testis CDK2 phosphorylation. The authors also show that in the absence of CDK2, some telomeres are unable to attach to the nuclear envelope and remain at the nuclear interior in later prophase I stages. The authors propose that CDK2 is essential for the correct attachment of meiotic telomeres to the nuclear envelope in prophase I, and that it is a key factor governing the assembly, structure and dynamics of the meiotic nuclear envelope in mice.

© 2015. Published by The Company of Biologists Ltd
2015