REC8
Meiotic recombination protein REC8 homolog is a protein that in humans is encoded by the REC8 gene.[1][2][3][4]
Rec8 is an important component of Cohesin complex that binds sister chromatids together during Meiosis. Rec8 is sequentially degraded first from chromatid arms in meiosis I, then from centromeric regions in meiosis II. Careful regulation of Rec8 degradation during each round of meiotic cell division ensures that karyokinesis in meiosis I segregates chromosome homologs, while karyokinesis in meiosis II results in segregation of sister chromatids.
Function
This gene encodes a member of the kleisin family of SMC (structural maintenance of chromosome) protein partners. The protein localizes to the axial elements of chromosomes during meiosis in both oocytes and spermatocytes. In the mouse, the homologous protein is a key component of the meiotic cohesion complex, which regulates sister chromatid cohesion and recombination between homologous chromosomes. Multiple alternatively spliced variants, encoding the same protein, have been found for this gene.[4]
Rec8 remains in complex with SMC proteins until anaphase, where it is degraded by Separase once the spindle assembly checkpoint is bypassed. Unlike the other Kleisin family member, Scc1, Rec8 must be phosphorylated prior to degradation. Prior to anaphase, Rec8 is protected from phosphorylation by Protein Phosphatase 2 (PP2A-B56) in mouse. PP2A is recruited to cohesin by Shugosin 2 (Sgo2; SGOL2 in yeast). Bypass of the spindle assembly checkpoint activates Separase, which then degrades phosphorylated Rec8 and untethers Cohesin from sister chromatids, allowing for segregation of chromosomes.
Interactions
REC8 has been shown to interact with SMC3.[3]
References
- ↑ Parisi S, McKay MJ, Molnar M, Thompson MA, van der Spek PJ, van Drunen-Schoenmaker E, Kanaar R, Lehmann E, Hoeijmakers JH, Kohli J (May 1999). "Rec8p, a meiotic recombination and sister chromatid cohesion phosphoprotein of the Rad21p family conserved from fission yeast to humans". Molecular and Cellular Biology 19 (5): 3515–28. PMC 84144. PMID 10207075.
- ↑ Xu H, Beasley MD, Warren WD, van der Horst GT, McKay MJ (Jun 2005). "Absence of mouse REC8 cohesin promotes synapsis of sister chromatids in meiosis". Developmental Cell 8 (6): 949–61. doi:10.1016/j.devcel.2005.03.018. PMID 15935783.
- 1 2 Lee J, Iwai T, Yokota T, Yamashita M (Jul 2003). "Temporally and spatially selective loss of Rec8 protein from meiotic chromosomes during mammalian meiosis". Journal of Cell Science 116 (Pt 13): 2781–90. doi:10.1242/jcs.00495. PMID 12759374.
- 1 2 "Entrez Gene: REC8L1 REC8-like 1 (yeast)".
Further reading
- Kimura K, Wakamatsu A, Suzuki Y, Ota T, Nishikawa T, Yamashita R, Yamamoto J, Sekine M, Tsuritani K, Wakaguri H, Ishii S, Sugiyama T, Saito K, Isono Y, Irie R, Kushida N, Yoneyama T, Otsuka R, Kanda K, Yokoi T, Kondo H, Wagatsuma M, Murakawa K, Ishida S, Ishibashi T, Takahashi-Fujii A, Tanase T, Nagai K, Kikuchi H, Nakai K, Isogai T, Sugano S (Jan 2006). "Diversification of transcriptional modulation: large-scale identification and characterization of putative alternative promoters of human genes". Genome Research 16 (1): 55–65. doi:10.1101/gr.4039406. PMC 1356129. PMID 16344560.
- Prieto I, Tease C, Pezzi N, Buesa JM, Ortega S, Kremer L, Martínez A, Martínez-A C, Hultén MA, Barbero JL (2004). "Cohesin component dynamics during meiotic prophase I in mammalian oocytes". Chromosome Research 12 (3): 197–213. doi:10.1023/B:CHRO.0000021945.83198.0e. PMID 15125634.
- Schleiffer A, Kaitna S, Maurer-Stroh S, Glotzer M, Nasmyth K, Eisenhaber F (Mar 2003). "Kleisins: a superfamily of bacterial and eukaryotic SMC protein partners". Molecular Cell 11 (3): 571–5. doi:10.1016/S1097-2765(03)00108-4. PMID 12667442.