Funktionelle Architektur des Synaptonemalen Komplexes
Final Report Abstract
During the prophase of the first meiotic division homologous chromosomes undergo synapsis, a key event that is crucial for their proper segregation during meiotic division I. Defective synapsis of homologous chromosomes has deleterious consequences for meiosis that frequently lead to infertility. Synapsis of homologous chromosomes is mediated by the synaptonemal complex. Synaptonemal complexes (SCs) are evolutionary conserved meiosis-specific karyoskeletal structures that were discovered 51 years ago SCs show a tripartite ladder-like organization characterized by the presence of two lateral elements to which the chromatin loops of the individual homologous chromosomes are attached. The third component - the central region - holds the SC together and is located in the gap between lateral elements. The central region is composed of a central element and numerous perpendicularly-oriented transverse filaments that link the lateral elements with the central element. The functional significance of the SC for meiosis has been a matter of debate. However, evidence has accumulated in the past indicating that it plays a key role during synapsis of homologous chromosomes, chiasmata formation and chromosome segregation. Major components of mammalian SCs are the meiosis-specific proteins SYCP1, 2 and 3. Proteins SYCP2 and SYCP3 are structural components of lateral elements, while the central element and transverse filaments are largely composed of protein SYCP1. Although the structure of SCs is highly conserved among eukaryotes, this is not the case for the SC protein components which are rather divergent in the amino acid sequence. A comparison of the primary structure of mammalian SC proteins with that of invertebrates, funghi and plants revealed almost no sequence homologies. Here we have investigated the properties of major SC protein components of vertebrates. We have focused our interest on proteins SYCP1 and SYCP3 and their binding partners in order to provide relevant information for our understanding of SC assembly and function.
Publications
- Architecture of meiotic chromosomes: polymerization properties of synaptonemal complex protein SYCP1 and characterization of binding partners. (PhD thesis, 2005)
Ruppert Öllinger
- The mammalian protein SCP1 forms synaptonemal complex-like structures in the absence of meiotic chromosomes. Mol. Biol. Cell 16: 212-217 (2005)
Öllinger R, Alsheimer M & Benavente R
- Two novel proteins recruited by synaptonemal complex protein 1 (SYCP1) are at the centre of meiosis. J. Cell Sci. 118: 2755-2762 (2005)
Costa Y, Speed R, Öllinger R, Alsheimer M, Semple C, Gautier P, Maratou K, Novak I, Höög C, Benavente R & Cooke HJ
- Characterization of a novel meiosis-specific protein within the central element of the synaptonemal complex. J. Cell Sci. 119: 4025-4032 (2006)
Hamer G, Gell K, Kouznetsova A, Novak I, Benavente R & Höög C
- The synaptonemal complex – 50 years. Chromosoma 115: 151-271 (2006)
Benavente R
- SYCE2 is required for synaptonemal complex assembly, DSB repair and homologous recombination. J. Cell Biol. 176: 741-747 (2007)
Bolcun-Filas E, Costa Y, Speed R, Taggart M, Benavente R, de Rooij DG & Cooke HJ
- Synaptonemal complex protein SYCP3: Conserved polymerization properties among vertebrates. Biochim. Biophys. Acta (2007)
Baier A, Alsheimer M & Benavente R
(See online at https://doi.org/10.1016/j.bbapap.2007.03.008)
