SUMMARY PARAGRAPH for MCD1
MCD1 is an essential gene that encodes a subunit of the yeast cohesin complex, which is required for sister chromatid cohesion in mitosis and meiosis (3, 1, 2, 5, 6, 7, 8). Temperature-sensitive mutations in MCD1 cause defects in sister chromatid cohesion, chromosome condensation, and chromosome segregation (3, 1, 2, 5).
The yeast cohesin complex includes Smc1p and Smc3p, two members of a conserved family of chromosomal ATPases, and Irr1p (1, 5, 7, 8). Cohesin associates with centromeres and other discrete sites along chromosome arms prior to metaphase; the association with centromeres requires the centromere protein Mif2p, the centromere binding complex CBF3, and Cse4p (9, 10, 11). Scc2p is not a stoichiometric cohesin subunit, but is required for the cohesin complex to associate with chromosomes (5).
The level of Mcd1p is cell cycle regulated, and peaks in S phase (3, 1); Mcd1p must be present during S phase for sister chromatid cohesion to be established (12). Mcd1p dissociates from chromosomes upon the loss of sister chromatid cohesion at the metaphase-to-anaphase transition (3). Dissociation of Mcd1p from chromatin requires Esp1, a separin that stimulates proteolysis of Mcd1p (13, 14).
Mcd1p shares homology with the S. pombe Rad21 protein and with putative proteins encoded by ORFs from human, mouse, and C. elegans (1). Cohesin complexes have been identified in other eukaryotes, including Xenopus, C. elegans, S. pombe, and human (7).
Last updated: 2000-05-04