DNA topoisomerase II interacts with Lim15/Dmc1 in meiosis

Abstract

Lim15/Dmc1 is a meiosis specific RecA-like protein. Here we propose its participation in meiotic chromosome pairing-related events along with DNA topoisomerase II. Analysis of protein–protein interactions using in vitro binding assays provided evidence that Coprinus cinereus DNA topoisomerase II (CcTopII) specifically interacts with C.cinereus Lim15/Dmc1 (CcLim15). Co-immunoprecipitation experiments also indicated that the CcLim15 protein interacts with CcTopII in vivo. Furthermore, a significant proportion of CcLim15 and CcTopII could be shown to co-localize on chromosomes from the leptotene to the zygotene stage. Interestingly, CcLim15 can potently activate the relaxation/catenation activity of CcTopII in vitro, and CcTopII suppresses CcLim15-dependent strand transfer activity. On the other hand, while enhancement of CcLim15's DNA-dependent ATPase activity by CcTopII was found in vitro, the same enzyme activity of CcTopII was inhibited by adding CcLim15. The interaction of CcLim15 and CcTopII may facilitate pairing of homologous chromosomes.

Disruption of Topoisomerase II Perturbs Pairing in Drosophila Cell Culture

“…Our findings are consistent with proposals suggesting that topoisomerase II may contribute to pairing during meiosis (Cobb et al 1997;Vazquez et al 2002;Iwabata et al 2005). In this regard, it is of interest that Spo11, which is homologous to a type II DNA topoisomerase, promotes meiotic pairing through the generation of Curiously, absence of Spo11, as well as other genetic backgrounds, can lead to the meiotic pairing of nonhomologous chromosomes (Mcclintock 1933;reviewed by Mckee 2004;Gerton and Hawley 2005;Pawlowski and Cande 2005;Colaiacovo 2006;Osman et al 2006;Zickler 2006; also see Tsubouchi and Roeder 2005), which was proposed by Mcclintock (1933) to be competitive with homologous pairing.…”

“…For example, it may bring and/or hold homologs together by altering DNA topology, modifying chromatin or chromosome structure, or catenating DNA molecules (Bachant et al 2002;Vazquez et al 2002;Iwabata et al 2005). Alternatively, it may dimerize while bound to DNA or via its role as a chromosome structural/scaffold protein Gasser et al 1986; more recently Maeshima and Laemmli 2003;Maeshima et al 2005); for instance, it may act in conjunction with Su(Hw) (Fritsch et al 2006), whose DNA binding site contains the in vitro recognition sequence for topoisomerase II (Nabirochkin et al 1998).…”

Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 1: Background to spermatogenesis, spermatogonia, and spermatocytes

“…DMC1 interacts with it and both colocalize on chromosomes from leptotene to zygotene spermatocytes. The interaction of the two may facilitate pairing of homologous chromosomes (Iwabata et al, 2005). Deletion of Dmc1 in mice leads to infertility because of a defect in meiotic homologous chromosome pairing and an arrest in zygotene spermatocytes (Pittman et al, 1998;Shinohara and Ogawa, 1999;Yoshida et al, 1998).…”

Coprinus cinereus Mer3 is required for synaptonemal complex formation during meiosis

“…Not only is its meiotic cell cycle long and naturally synchronous, but large populations of synchronous meiotic cells are also easy to obtain (Li et al 1999;Kües 2000;Kamada 2002;Casselton and Olesnicky 1998). These advantages have enabled us to isolate and characterize many synapsis-related proteins in C. cinereus (Nara et al 1999(Nara et al , 2001Hamada et al 2007;Ishizaki et al 2002;Namekawa et al 2003a, b, c;Yamaguchi et al 2004;Iwabata et al 2005;Koshiyama et al 2006;Sakamoto et al 2007;Sakaguchi et al 2007) and to demonstrate their roles in vivo.…”