Monopolin is a protein complex, originally identified in Saccharomyces cerevisiae, that is required for the segregation of homologous centromeres to opposite poles of a dividing cell during meiosis I [1][3]. The orthologous complex in Schizosaccharomyces pombe is not required for meiosis I chromosome segregation, but is proposed to play a similar physiological role in clamping microtubule binding sites [2]. In S .cerevisiae this subunit is called LRS4, and in S. pombe it is known as Mde4.

1: Functional genomics identifies monopolin: a kinetochore protein required for segregation of homologs during meiosis i. Toth A, Rabitsch KP, Galova M, Schleiffer A, Buonomo SB, Nasmyth K; Cell. 2000;103:1155-1168. PMID:11163190

2: The kinetochore proteins Pcs1 and Mde4 and heterochromatin are required to prevent merotelic orientation. Gregan J, Riedel CG, Pidoux AL, Katou Y, Rumpf C, Schleiffer A, Kearsey SE, Shirahige K, Allshire RC, Nasmyth K; Curr Biol. 2007;17:1190-1200. PMID:17627824

3: Kinetochore recruitment of two nucleolar proteins is required for homolog segregation in meiosis I. Rabitsch KP, Petronczki M, Javerzat JP, Genier S, Chwalla B, Schleiffer A, Tanaka TU, Nasmyth K; Dev Cell. 2003;4:535-548. PMID:12689592