The Chromosome Axis Controls Meiotic Events through a Hierarchical Assembly of HORMA Domain Proteins

• Published in: Developmental cell 2014-11, Vol.31 (4), p.487-502
• Main Authors: Kim, Yumi, Rosenberg, Scott C., Kugel, Christine L., Kostow, Nora, Rog, Ofer, Davydov, Vitaliy, Su, Tiffany Y., Dernburg, Abby F., Corbett, Kevin D.
• Format: Article
• Language: English
• Subjects: Animals; Caenorhabditis elegans; Caenorhabditis elegans - cytology; Caenorhabditis elegans - metabolism; Caenorhabditis elegans Proteins - metabolism; Cell Cycle Proteins - metabolism; Chromosome Pairing - genetics; Chromosome Segregation - physiology; Chromosomes - metabolism; Meiosis - physiology; Mutation - genetics; Synaptonemal Complex - metabolism
• ISSN: 1534-5807; 1878-1551
• DOI: 10.1016/j.devcel.2014.09.013

Proteins of the HORMA domain family play central, but poorly understood, roles in chromosome organization and dynamics during meiosis. In Caenorhabditis elegans, four such proteins (HIM-3, HTP-1, HTP-2, and HTP-3) have distinct but overlapping functions. Through combined biochemical, structural, and in vivo analysis, we find that these proteins form hierarchical complexes through binding of their HORMA domains to cognate peptides within their partners’ C-terminal tails, analogous to the “safety belt” binding mechanism of Mad2. These interactions are critical for recruitment of HIM-3, HTP-1, and HTP-2 to chromosome axes. HTP-3, in addition to recruiting the other HORMA domain proteins to the axis, plays an independent role in sister chromatid cohesion and double-strand break formation. Finally, we find that mammalian HORMAD1 binds a motif found both at its own C terminus and at that of HORMAD2, indicating that this mode of intermolecular association is a conserved feature of meiotic chromosome structure in eukaryotes. [Display omitted] •HORMA proteins play central but mysterious roles in meiotic chromosome metabolism•In C. elegans and mammals, HORMA proteins assemble through head-to-tail interactions•Hierarchical assembly of HORMA domain proteins underlies chromosome axis structure•Disruption of specific binding interactions allows targeted analysis in vivo Kim, Rosenberg, et al. find that the meiotic HORMA domain proteins in C. elegans assemble into complexes along the chromosome axis through head-to-tail binding interactions, which are likely conserved throughout eukaryotes. Hierarchical assembly of HORMA proteins underlies chromosome axis structure and is important for meiotic recombination and chromosome segregation.