| Structural highlights
Function
GEMI_HUMAN Inhibits DNA replication by preventing the incorporation of MCM complex into pre-replication complex (pre-RC). It is degraded during the mitotic phase of the cell cycle. Its destruction at the metaphase-anaphase transition permits replication in the succeeding cell cycle.[1] [2] [3] Inhibits the transcriptional activity of a subset of Hox proteins, enrolling them in cell proliferative control.[4] [5] [6]
Publication Abstract from PubMed
Geminin is an important regulator of proliferation and differentiation in metazoans, which predominantly inhibits the DNA replication licensing factor Cdt1, preventing genome over-replication. We show that Geminin preferentially forms stable coiled-coil heterodimers with its homologue, Idas. In contrast to Idas:Geminin heterodimers, Idas homodimers are thermodynamically unstable and are unlikely to exist as a stable macromolecule under physiological conditions. The crystal structure of the homology regions of Idas in complex with Geminin showed a tight head-to-head heterodimeric coiled-coil. This Idas:Geminin heterodimer binds Cdt1 less strongly than Geminin:Geminin, still with high affinity (~30nM), but with notably different thermodynamic properties. Consistently, in Xenopus egg extracts, Idas:Geminin is less active in licensing inhibition compared to a Geminin:Geminin homodimer. In human cultured cells, ectopic expression of Idas leads to limited over-replication, which is counteracted by Geminin co-expression. The properties of the Idas:Geminin complex suggest it as the functional form of Idas, and provide a possible mechanism to modulate Geminin activity.
The Geminin and Idas coiled coils preferentially form a heterodimer that inhibits Geminin function in DNA replication licensing.,Caillat C, Pefani ED, Gillespie PJ, Taraviras S, Blow JJ, Lygerou Z, Perrakis A J Biol Chem. 2013 Oct 2. PMID:24064211[7]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ McGarry TJ, Kirschner MW. Geminin, an inhibitor of DNA replication, is degraded during mitosis. Cell. 1998 Jun 12;93(6):1043-53. PMID:9635433
- ↑ Sugimoto N, Tatsumi Y, Tsurumi T, Matsukage A, Kiyono T, Nishitani H, Fujita M. Cdt1 phosphorylation by cyclin A-dependent kinases negatively regulates its function without affecting geminin binding. J Biol Chem. 2004 May 7;279(19):19691-7. Epub 2004 Mar 1. PMID:14993212 doi:10.1074/jbc.M313175200
- ↑ Zhou B, Liu C, Xu Z, Zhu G. Structural basis for homeodomain recognition by the cell-cycle regulator Geminin. Proc Natl Acad Sci U S A. 2012 May 21. PMID:22615398 doi:10.1073/pnas.1200874109
- ↑ McGarry TJ, Kirschner MW. Geminin, an inhibitor of DNA replication, is degraded during mitosis. Cell. 1998 Jun 12;93(6):1043-53. PMID:9635433
- ↑ Sugimoto N, Tatsumi Y, Tsurumi T, Matsukage A, Kiyono T, Nishitani H, Fujita M. Cdt1 phosphorylation by cyclin A-dependent kinases negatively regulates its function without affecting geminin binding. J Biol Chem. 2004 May 7;279(19):19691-7. Epub 2004 Mar 1. PMID:14993212 doi:10.1074/jbc.M313175200
- ↑ Zhou B, Liu C, Xu Z, Zhu G. Structural basis for homeodomain recognition by the cell-cycle regulator Geminin. Proc Natl Acad Sci U S A. 2012 May 21. PMID:22615398 doi:10.1073/pnas.1200874109
- ↑ Caillat C, Pefani ED, Gillespie PJ, Taraviras S, Blow JJ, Lygerou Z, Perrakis A. The Geminin and Idas coiled coils preferentially form a heterodimer that inhibits Geminin function in DNA replication licensing. J Biol Chem. 2013 Oct 2. PMID:24064211 doi:http://dx.doi.org/10.1074/jbc.M113.491928
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