PCH2

PCH2 is a conserved gene encoding a HORMA-domain-containing AAA+ ATPase. In budding yeast it is referred to as Pch2, while in vertebrates the ortholog is TRIP13. The protein is involved in meiotic prophase I, where it contributes to chromosome axis remodeling and synaptonemal complex assembly and participates in the pachytene checkpoint that monitors recombination and synapsis progression.

Mechanistically, PCH2 remodels HORMA-domain proteins through ATP hydrolysis, promoting conformational changes that regulate their interactions and turnover on meiotic chromosomes. In yeast, this includes effects on Hop1 distribution and its association with chromosome axes.

PCH2 is broadly conserved across eukaryotes. Its yeast counterpart is Pch2; in mammals the homolog is TRIP13; in nematodes the gene is PCH-2. The protein typically contains an N-terminal HORMA domain and a C-terminal AAA+ ATPase motor, enabling energy-dependent remodeling of HORMA-domain proteins.

Significance: PCH2/TRIP13 has attracted research attention for its role in meiosis and checkpoint signaling, contributing to proper crossover formation and chromosome segregation. Dysregulation can lead to meiotic defects and aneuploidy; in humans, TRIP13 has also been studied in the context of the mitotic spindle checkpoint and cancer, where altered expression may influence chromosome stability.