Cohesin subunit Rad21L, the new kid on the block has new ideas

Abstract

Rad21L—a new meiotic cohesin described in a recent paper in EMBO reports by the Watanabe group—probably has a role in the establishment of homologous chromosome recognition.

Figure 1

Rad21L, a new cohesin subunit with unprecedented features. (A) Subunit composition of vertebrate cohesin complexes. The mitotic and three main meiotic complexes are shown, including that containing Rad21L. (B) Model for the localization of cohesin complexes during meiosis. Rec8 and Rad21L cohesin complexes establish sister chromatid cohesion during premeiotic S-phase and act as a basis for lateral-element formation, but only Rad21L recruits SYCP1. Nucleation of synaptonemal-complex assembly is facilitated by the matching patterns of Rad21L on homologous chromosomes. Once recombination is complete, phosphorylation of Rad21L-containing complexes dissociates them from chromosomes, facilitating subsequent synaptonemal-complex disassembly. Rad21^Scc1-containing cohesin is then recruited to chromosomes.