Protein SYCP2 provides a link between transverse filaments and lateral elements of mammalian synaptonemal complexes.
Synaptonemal complexes (SCs) are evolutionarily conserved meiosis-specific nuclear structures critically involved in synapsis, recombination, and segregation of homologous chromosomes. SCs are proteinaceous structures composed of (a) two lateral elements (LEs), to which the chromatin of the homologs is attached, (b) numerous transverse filaments (TFs) that link the LEs, and (c) a central element (CE). Major protein components of mammalian SCs are the TF protein SYCP1 and the LE proteins SYCP2 and SCYP3. How SCs become assembled is presently poorly understood, in particular, it is not known how TFs assemble at the plane of LEs to interconnect the homologous chromosomes. Therefore, we have investigated possible interactions between SYCP1 and other SC proteins. In immunoprecipitation experiments we could find that SYCP1 and SYCP2 interact in extracts of meiotic cells. Using the yeast two-hybrid system, we were able to demonstrate that the C-terminus of SYCP1 directly interacts with SYCP2. These results were confirmed by different interaction traps. Furthermore, we could narrow down the interacting domain of the SYCP2 molecule to its C-terminal region. We propose that SYCP2 acts as a linker between SYCP1 and SYCP3 and therefore would be the missing connecting link between LEs and TFs essential for proper chromosome synapsis.
Winkel
Karoline
K
Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Am Hubland, Germany.
Alsheimer
Manfred
M
Ollinger
Rupert
R
Benavente
Ricardo
R
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D019556:COS Cells; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002522:Chlorocebus aethiops; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D054730:Protein Interaction Domains and Motifs; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013573:Synaptonemal Complex / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D011994:Recombinant Proteins; C078744:Sycp1 protein, rat; C113093:Sycp2 protein, rat; C085453:Sycp3 protein, rat