MSH4
Description
The MSH4 (mutS homolog 4) is a protein-coding gene located on chromosome 1.
MutS protein homolog 4 is a protein that in humans is encoded by the MSH4 gene. The MSH4 and MSH5 proteins form a hetero-oligomeric structure (heterodimer) in yeast and humans. In the yeast Saccharomyces cerevisiae, MSH4 and MSH5 act specifically to facilitate crossovers between homologous chromosomes during meiosis. The MSH4/MSH5 complex binds and stabilizes double Holliday junctions and promotes their resolution into crossover products. An MSH4 hypomorphic (partially functional) mutant of S. cerevisiae showed a 30% genome-wide reduction in crossover numbers and a large number of meioses with non-exchange chromosomes. Nevertheless, this mutant gave rise to spore viability patterns suggesting that segregation of non-exchange chromosomes occurred efficiently. Thus, in S. cerevisiae, proper segregation apparently does not entirely depend on crossovers between homologous pairs. The him-14 gene of the worm Caenorhabditis elegans encodes an ortholog of MSH4. Formation of crossovers during C. elegans meiosis requires the him-14(MSH4) gene. Loss of him-14(MSH-4) function severely reduces crossing over, resulting in a lack of chiasmata between homologs and consequent missegregation.
MSH4 is also known as ASG, POF20, SPGF2.
