MutS Homolog 4 (MSH4)

The Escherichia coli MutHLS system has been highly conserved throughout evolution. The eukaryotic pathway results in a specialization of MutS homologs such as MSH2 that have evolved to play crucial roles in both DNA mismatch repair and meiotic recombination. Meiosis-specific genes belonging to this family had been identified only in yeast. In Saccharomyces cerevisiae, MSH4 (MutS homolog 4) is a meiosis-specific protein that is not involved in mismatch correction. This protein is required for reciprocal recombination and proper segregation of homologous chromosomes at meiosis I. The predicted 936-amino acid sequence shows 28.7% identity with the S. cerevisiae MSH4 protein. By Northern blot analysis, human MSH4 transcripts were detectable only in testis and in ovary with a lower level of expression.